JP7010185B2 - Master device, master device control method, information processing program, and recording medium - Google Patents

Description

The present invention relates to a master device or the like in a master-slave control system.

Conventionally, in the field of FA (Factory Automation), attempts have been made to efficiently collect and manage data related to production equipment and the like installed in factories and the like. For example, in Patent Document 1 below, a PLC that collects control data at a collection interval set by a higher-level device and transfers the collected control data to a higher-level device at a transfer interval equal to or larger than the collection interval. (Programmable Logic Controller) is disclosed.

Republished WO 2012/111653

However, in the conventional technology as described above, when the PLC transfers control data such as device data acquired for each control cycle to a higher-level device, when the processing load of the processing related to the transfer becomes large, other than the transfer of the control processing or the like. There is a problem that it can adversely affect the execution of the processing of. More specifically, in the prior art, when the processing load of the master device in the master-slave control system such as PLC becomes large in the process of collecting the data to be transmitted to the external device such as an external server from the control data. , There is no point of view that the execution of processes other than the collection process can be affected. Details will be described below.

In general, control data such as device data acquired by a PLC for each control cycle has an extremely large number of types and quantities, and it is not efficient to transfer all of them to an external device such as an external server. Therefore, for example, the PLC collects desired data from the control data acquired for each control cycle, and transmits the collected desired data to an external device.

However, for example, in order to precisely monitor and verify the FA system constructed as a master-slave control system, there is a desire to store as much control data as possible in the external device as the target of monitoring and verification. be. Therefore, the PLC is expected to collect as much data as possible from the control data acquired for each control cycle as desired data to be transmitted to the external device.

Therefore, for the master device in the master-slave control system such as PLC, the processing load of the process of collecting the data to be transmitted to the external device from the control data may become large enough to affect the execution of the process other than the collection process. There is.

One aspect of the present invention has been made in view of the above-mentioned problems, and the user is responsible for the processing load of the process of collecting the data to be transmitted to the external device from the control data of the master device in the master-slave control system. The purpose is to be manageable.

In order to solve the above problems, the master device according to one aspect of the present invention is a master device in a master-slave control system, and a plurality of control data periodically acquired from the slave device should be transmitted to an external device. A collection unit that repeatedly collects each of the data according to a predetermined collection rule, a reception unit that accepts the maximum value specified by the user for the amount of data collected by the collection unit per unit time, and the predetermined collection unit. With the first adjustment unit that adjusts the predetermined collection rule so that the amount of data collected per unit time by the collection unit according to the collection rule of the above is less than or equal to the maximum value accepted by the reception unit. , Is equipped.

According to the above configuration, the master device adjusts the predetermined collection rule so that the amount of data to be collected per unit time is equal to or less than the maximum value, and the master device adjusts the predetermined collection rule according to the adjusted collection rule. Each of the plurality of data is repeatedly collected from the control data.

Here, it is clear that the larger the amount of data to be collected per unit time, the larger the processing load per unit time related to the data collection of the master apparatus. That is, the maximum value corresponds to the processing load per unit time related to the data collection of the master device.

Therefore, the master device transfers the control data to an external device such as the external server so that the processing load per unit time related to data collection is equal to or less than the processing load corresponding to the maximum value specified by the user. It has the effect of being able to collect data to be transmitted. In other words, the master device has an effect that the user can manage the processing load related to the process of collecting each of the plurality of data from the control data. Specifically, the user should send data to the master device with an appropriate processing load that does not affect the execution of "processing other than data collection processing such as control processing for the slave target". Can be collected from the control data.

In addition, the "data amount of data collected by the master device per unit time" is easy for the user to intuitively grasp, and the "processing load of the master device per unit time related to data collection" is accurate. It is an index that can be shown in.

Therefore, the master device is based on the "data amount of data to be collected per unit time" which is accurate as an index of "processing load per unit time related to data collection" and which is easy for the user to intuitively understand. This has the effect of being able to manage the data collection process.

In the master apparatus according to one aspect of the present invention, the predetermined collection rule includes a sequence indicating the collection order of each of the plurality of data collected by the collection unit, and the collection unit includes the collection unit of the plurality of data. Each is repeatedly collected according to the order, and the amount of data collected per unit time by the collection unit according to the predetermined collection rule is the data of the data collected by the collection unit before one cycle of the order. It may be a value obtained by dividing the amount by the time required by the collecting unit to make a round of the order.

According to the above configuration, the master device repeats from the control data according to the order and collects each of the plurality of data to be transmitted to the external device.

Therefore, the master device has an effect that, for example, data for monitoring and verifying the master-slave control system can be repeatedly collected from the control data in the collection order shown in the order.

In the master device according to one aspect of the present invention, the first adjusting unit, as the predetermined collection rule, (1) the number of appearances of each of the plurality of data in the sequence, and (2) the plurality of data. The number of data points collected for each appearance in the sequence, and (3) the number of data collected per unit time for each appearance of the plurality of data in the sequence. The frequency and (4) at least one of the times required by the collector to make a round of the sequence may be adjusted.

According to the above configuration, as the predetermined collection rule, the master device collects the number of appearances of each of the plurality of data, the number of data points collected for each appearance in the sequence, the collection frequency, and the collection frequency. , Adjust at least one of the times required to go around the sequence.

Here, when "each of the plurality of data" at each of the plurality of time points is stored in an external device such as the external server and a consistent analysis is to be performed, the data is transmitted to the external device. It is desirable that the collection frequency of each of the plurality of data is invariant at each of the plurality of time points. For example, for a data Da, if the acquisition frequency at one time point T1 is 500 Hz, then the collection frequency of that data Da at another time point T2 is consistent with that data Da. If you are going to perform a sexual analysis, it is desirable to set it to 500Hz. Therefore, for example, when collecting each of the plurality of data for the purpose of consistent analysis, the master device may change the collection frequency of each of the plurality of data when collecting each of the plurality of data. Instead, adjust the other items included in the prescribed collection rules. Specifically, the master device goes around the number of appearances of each of the plurality of data, the number of data points to be collected for each appearance in the sequence, and the sequence as the predetermined collection rule. Adjust at least one of the time required for.

Further, when it is desired to collect each of the plurality of data in a predetermined order evenly (that is, without being biased to a specific data), the master device may use the master device to collect the number of appearances and the order of each of the plurality of data. The number of data points collected for each appearance in is not changed. The master device adjusts at least one of the collection frequency of each of the plurality of data and the time required to go around the sequence among the predetermined collection rules, and from the control data, the plurality of data. Collect each of the data of.

Further, when it is not necessary to continuously collect each of the plurality of data (= collection period), the master device adjusts the time required to go around the sequence among the predetermined collection rules. .. For example, when the master device repeatedly collects three types of data Da, Db, and Dc in this order, the free time (= waiting time) is inserted as follows, and "Da, Db, and Dc are each set. , In this order, adjust the time required to "collect once". That is, the master device is used for "from the end of Da collection to the start of Db collection", "from the end of Db collection to the start of Dc collection", and "from the end of Dc collection to the start of Da collection". Insert free time in at least one of "until the start of collection".

That is, the master device sets the number of appearances of each of the plurality of data, the number of data points to be collected for each appearance in the sequence, the collection frequency, and the sequence among the predetermined collection rules. Adjust at least one of the time it takes to make a round. Therefore, the master device appropriately adjusts the items suitable for the purpose of using the plurality of data among the predetermined collection rules, and the processing load related to the data collection is equal to or less than the processing load corresponding to the maximum value. As such, it has the effect of being able to collect the plurality of data.

In the master device according to one aspect of the present invention, when the evaluation value given to each of the plurality of data collected by the collecting unit meets a predetermined criterion, the evaluation value satisfying the predetermined criterion is given. For the data, (1) the number of appearances in the sequence, (2) the number of data points collected for each appearance in the sequence, and (3) per unit time for each appearance in the sequence. Further, a second adjusting unit for adjusting at least one of the collection frequencies, which is the number of data points to be collected, is further provided, and the first adjusting unit is the number of appearances adjusted by the second adjusting unit, once in the order. The number of data points collected for each appearance and the predetermined collection rule including the collection frequency may be further adjusted using the maximum value.

According to the above configuration, the master device collects each of the plurality of data for each appearance count and one appearance in the sequence according to the evaluation value given to each of the plurality of data. The number of data points to be generated and at least one of the collected frequencies are adjusted.

For example, the master device increases the number of appearances, the number of data points collected for each appearance in the sequence, and at least one of the collection frequencies for data to which a high evaluation value is given. Further, the master device reduces at least one of the number of appearances, the number of data points collected for each appearance in the sequence, and the collection frequency for data to which a low evaluation value is given.

Therefore, the master device obtains each of the plurality of data at the number of appearances, the number of data points collected for each appearance in the sequence, and the collection frequency according to the evaluation value of each. It has the effect of being able to collect.

Here, the master device includes the number of appearances of each of the plurality of data adjusted according to the evaluation value, the number of data points collected for each appearance in the sequence, and the collection frequency. The predetermined collection rules are further adjusted using the maximum values.

Therefore, the master device performs processing for each of the plurality of data according to the respective evaluation values, and the processing load per unit time for collecting each of the plurality of data corresponds to the maximum value. It has the effect of being able to collect data so that it is below the load.

In the master apparatus according to one aspect of the present invention, the first adjusting unit is (1) the number of data points collected for each appearance of each of the plurality of data in the order, and (2) the said. At least one of the collection frequencies, which is the number of data points collected per unit time for each appearance in the sequence of each of the plurality of data, may be reduced at a uniform rate.

According to the above configuration, the master device collects the number of data points of each of the plurality of data for each appearance in the sequence, and the collection frequency, as an adjustment of the predetermined collection rule. Make at least one smaller at a uniform rate.

For example, when it is desired to collect each of the plurality of data in a predetermined order, the master device does not change "the number of appearances of each of the plurality of data in the order" among the predetermined collection rules. .. Instead, the master device reduces the number of data points collected for each occurrence of each of the plurality of data and at least one of the collected frequencies at a uniform rate. , Reduce the processing load related to data collection.

Therefore, for example, when the master device wants to collect each of the plurality of data in a predetermined order, the master device can collect the data without changing the "number of appearances of each of the plurality of data in the sequence". It has the effect of reducing the processing load.

The master device according to one aspect of the present invention is: (1) the maximum value, (2) data of data collected per unit time by the collecting unit according to the predetermined collecting rule adjusted by the first adjusting unit. The amount and (3) a display control unit for displaying the difference between the two to the user may be further provided.

According to the above configuration, the master device is the difference between the maximum value and the amount of data collected per unit time according to the adjusted predetermined collection rule, that is, processing related to data collection. The difference between the value indicating the allowable load value and the value indicating the actual processing load is displayed.

Therefore, the master device can notify the margin from the current processing load required for data collection to the allowable value of the processing load related to data collection so that the user can recognize at a glance. Play the effect of.

In the master device according to one aspect of the present invention, each of the plurality of data collected by the collecting unit is the data selected by the user as the collection target among the control data periodically acquired from the slave device. There may be.

According to the above configuration, the master device repeatedly collects the data selected as the collection target by the user from the control data periodically acquired from the slave device according to the predetermined collection rule.

Therefore, the master device may repeatedly collect only the data selected as the collection target by the user among the control data so that the data amount of the data to be collected per unit time is equal to or less than the maximum value. It has the effect of being able to do it.

In order to solve the above problems, the control method according to one aspect of the present invention is the control method of the master device in the master-slave control system, and the control data periodically acquired from the slave device is transmitted to the external device. A collection step in which each of a plurality of data to be collected is repeatedly collected according to a predetermined collection rule, and a reception step that accepts a maximum value specified by a user for the amount of data collected per unit time in the collection step. And, the predetermined collection rule is adjusted so that the amount of data collected per unit time in the collection step is equal to or less than the maximum value received in the reception step according to the predetermined collection rule. It includes a first adjustment step to be performed.

According to the method, the control method adjusts the predetermined collection rule so that the amount of data to be collected per unit time is equal to or less than the maximum value, and the control method adjusts the predetermined collection rule according to the adjusted collection rule. Each of the plurality of data is repeatedly collected from the control data.

Here, it is clear that the larger the amount of data to be collected per unit time, the larger the processing load per unit time related to the data collection of the control method. That is, the maximum value corresponds to the processing load per unit time related to the data collection of the control method.

Therefore, in the control method, the control data is transmitted to an external device such as an external server so that the processing load per unit time related to data collection is equal to or less than the processing load corresponding to the maximum value specified by the user. It has the effect of being able to collect data to be transmitted. In other words, the control method has the effect that the user can manage the processing load related to the process of collecting each of the plurality of data from the control data. Specifically, the user should send data to the master device with an appropriate processing load that does not affect the execution of "processing other than data collection processing such as control processing for the slave target". Can be collected from the control data.

In addition, the "data amount of data collected by the control method per unit time" is easy for the user to intuitively grasp, and the "processing load of the control method per unit time related to data collection" is accurate. It is an index that can be shown in.

Therefore, the control method is based on the "data amount of data to be collected per unit time" which is accurate as an index of "processing load per unit time related to data collection" and which is easy for the user to intuitively understand. This has the effect of being able to manage the data collection process.

According to one aspect of the present invention, the master device in the master-slave control system has an effect that the user can manage the processing load of the process of collecting the data to be transmitted to the external device from the control data.

It is a block diagram which shows the structure of the main part of PLC etc. which concerns on Embodiment 1 of this invention. It is a figure which shows the whole outline of the control system including PLC of FIG. It is a figure which shows the image of the method of collecting "data to be transmitted to a database" from the control data executed by PLC of FIG. It is a figure which shows an example of the data structure of a collection rule table. It is a flow diagram which shows the outline of the process which PLC of FIG. 1 performs. It is a figure which shows the example of the method of adjusting the collection rule based on the importance. This is an example of a collection rule table when the standard collection rule can be adopted without change. This is an example of a collection rule table when the standard collection rule cannot be adopted as it is. It is a figure explaining the tendency of the change of the average sampling rate when the collection rule of each I / O node is increased or decreased. It is a figure which shows an example of the adjustment method of a collection rule. It is a figure which shows the example different from the example of FIG. 10 about the adjustment method of a collection rule. It is a figure which shows the example different from the example of FIG. 10 and FIG. 11 about the adjustment method of a collection rule. This is an example of information to be displayed on the display screen of the external display device by the PLC of FIG. 1. It is an example of the data structure of the collection rule table different from that illustrated in FIG.

[Embodiment 1]
Hereinafter, embodiments according to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to FIGS. 1 to 14. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated. In the present embodiment, for example, a PLC (Programmable Logic Controller) 10 will be described as a typical example of the master device. In order to facilitate understanding of the PLC 10 according to one aspect of the present invention, first, an outline of the control system 1 including the PLC 10 will be described with reference to FIGS. 2 and 3.

§1. Application example (Overview of control system)
FIG. 2 is a diagram showing an overall outline of the control system 1. As shown in FIG. 2, the control system 1 includes PLC10 as a master device and servo drivers 30A, 30B, 30C, 30D, ... As one or more slave devices connected to the master device via a network. It is a master-slave control system including. Servo motors 40A, 40B, 40C, 40D are connected to each of the servo drivers 30A, 30B, 30C, and 30D.

In the following description, when it is not necessary to distinguish each of the servo drivers 30A, 30B, 30C, and 30D, it is simply referred to as "servo driver 30". Similarly, when it is not necessary to distinguish each of the servo motors 40A, 40B, 40C, and 40D, it is simply referred to as "servo motor 40".

The PLC 10 is a programmable controller that executes a user program for controlling a control device such as a servomotor 40, and is an upper controller for the servo driver 30 as a lower controller. The PLC 10 is called a "master device" in the sense that it manages data transmission via a network in the control system 1, while the servo driver 30 is called a "slave device". That is, the control system 1 is a master-slave control system including a PLC 10 as a master device and a servo driver 30 as one or more slave devices connected to the master device via a network. As a network connecting the PLC 10 and the servo driver 30, for example, EtherCAT (registered trademark) can be used.

The PLC 10 outputs a control instruction to the servo driver 30 at each control cycle and executes control to the servo driver 30. Further, the PLC 10 acquires data related to the output of the servomotor 40 (that is, control data indicating the state of the servomotor 40 such as torque, speed, and position) from the servo driver 30 for each control cycle.

The servo driver 30 is a control device for the servomotor 40, receives control instructions from the PLC 10 for each control cycle, and drives the servomotor 40 according to the received control instructions. Further, the servo driver 30 acquires actual measurement values related to the output (state) of the servo motor 40 such as position, speed, and torque from a position sensor and a torque sensor connected to the shaft of the servo motor 40, and these actual measurement values. The data related to the above is output to the PLC 10 for each control cycle. The servo driver 30 may also be referred to as a servo motor amplifier.

The slave device connected to the PLC 10 as the master device may include various device communication management units and the like in addition to the servo driver 30. One or more devices are connected to the device communication management unit via a device communication cable. The device connected to the device communication management unit is, for example, an input device such as a sensor, or an output device such as an actuator (Actuator). The PLC 10 can acquire information (for example, detection information from a sensor or the like) from each of one or more devices connected to the device communication management unit from the device communication management unit via a network. The data from these devices (device data, for example, detection information from a sensor or the like) is also control data that the PLC 10 as a master device periodically acquires from the slave device for each control cycle.

The "master device" and "slave device" are defined by focusing on the control function of data transmission on the network, and what kind of information is transmitted and received between each device is particularly limited. Not done. As a master device, the PLC 10 periodically acquires data (control data) output by a slave device such as a servo driver 30 for each control cycle. Then, the PLC 10 transmits at least a part of the control data acquired from the slave device such as the servo driver 30 for each control cycle to the external database 20.

The database 20 receives the data transmitted from the PLC 10, that is, at least a part of the control data acquired by the PLC 10 from the slave device for each control cycle, and stores the received data in the storage area.

Here, in general, the control data periodically acquired by the PLC 10 from a slave device such as the servo driver 30 for each control cycle tends to have a very large number of data. For example, if three types of servo data (control data) of "torque", "speed", and "position" are acquired from the servo driver 30 for 20 axes for each axis, the PLC 10 has 60 points for each control cycle. Servo data will be acquired.

Therefore, when all the control data acquired by the PLC 10 from the slave device for each control cycle is stored in the database 20, the amount of control data stored in the database 20 becomes enormous, and the storage area of the database 20 is immediately insufficient. It ends up. Further, when the user (person) selects the data to be stored in the database 20 from the huge amount of control data acquired by the PLC 10 for each control cycle, the control data indicating an abnormality of the control system 1 is stored in the database 20. You may miss the control data you want.

Therefore, the PLC 10 collects the data to be transmitted to the database 20 from the control data acquired from the slave device for each control cycle according to a predetermined collection rule, and transmits (that is, stores) the collected data to the database 20. .. In the following description, "collecting data to be transmitted to the database 20 from the control data periodically acquired from the slave device for each control cycle" is also referred to as "sampling".

However, if the method of simply "collecting data to be transmitted to the database 20 from the control data at a constant timing (time interval) and a constant sampling frequency" is executed, the following problems may occur. That is, there is a possibility that the control data that is not important to the user is excessively collected, or the control data that is important to the user cannot be collected in detail.

Further, if the processing load required for sampling is too large compared to the entire processing capacity (system performance) of the PLC 10, data to be transmitted to the database 20 may be missing due to memory exhaustion, buffer overflow, or the like. Furthermore, system resources are consumed for sampling, which may hinder the execution of control programs.

Therefore, the PLC 10 calculates the importance (evaluation value) for each of the plurality of data to be transmitted to the database 20, and uses the calculated importance to collect rules for each of the plurality of data to be transmitted to the database 20. To adjust. For example, the PLC 10 increases the collection frequency, sampling frequency, sampling point, etc. of high-importance data higher than the collection frequency, sampling frequency, sampling point, etc. of low-importance data. The PLC 10 collects high-importance control data in detail by adjusting the collection rules for each of the plurality of data using the importance of each of the plurality of data, and the less important control data. It is possible to avoid excessive collection.

Further, the PLC 10 adjusts the collection rule for each of the plurality of data to be transmitted to the database 20 so that the processing load related to the sampling process becomes equal to or less than the maximum value set by the user, and according to the adjusted collection rule. Execute sampling processing. Therefore, the PLC 10 can execute the sampling process under the control of the user so as not to affect the process other than the sampling process such as the control process for the slave device.

A tool (not shown) or the like may be connected to the PLC 10 via, for example, a communication cable which is a USB (Universal Serial Bus) cable. The tool is an information processing device for setting various parameters for the control system 1. For example, the information related to the collection rule of the sampling process executed by the PLC 10 (details will be described later) may be set by the tool. The tool typically consists of a general purpose computer. Instead of the tool, an HMI (Human Machine Interface) may be connected to the PLC 10 via a communication cable. The PLC 10 receives information about the collection rule related to the sampling process (for example, initial value, reference value, etc. for the collection rule) from, for example, a tool or the like.

FIG. 3 is a diagram showing an image of a method of collecting "data to be transmitted to the database 20" from the control data executed by the PLC 10, that is, a sampling process executed by the PLC 10. The PLC 10 treats each point of the I / O (control data) stored in the control data table 181 of FIG. 2 as a node (I / O node) of the network, and collects data at each I / O node while collecting data. It goes around the I / O node.

That is, the PLC 10 treats each of the various control data acquired from the servo driver 30 for each control cycle as a network node (I / O node) in which the PLC 10 as a master device controls transmission. The PLC 10 is, for example, "data indicating the torque of the axis 1 (TorqueData1)", "data indicating the speed of the axis 1 (VelocityData1)", and "data indicating the position of the axis 1" (data indicating the position of the axis 1) periodically acquired from the servo driver 30 (TorqueData1). Each of "PositionData1)" is treated as a node (I / O node).

Then, for the entire plurality of control data acquired from the slave device (that is, the control data group), the PLC 10 switches the I / O nodes to be collected in a predetermined order, and the PLC 10 of each I / O node. Collect data. The PLC10 first collects the data of "TorqueData1", then the data of "VelocityData1", the data of "PositionData1", and so on, and so on, and collects the data of each I / O node. do.

In FIG. 3, the PLC 10 displays six I / O nodes “A, B, C, D, E, F” in this order (that is, “A to B, B to C, C to C”). An image of performing sampling while patrolling from D to E, from E to F, from F to A again is shown. That is, the PLC 10 has "A, B, C, D, E, F, A, B, C, D" for each of the six I / O nodes of "A, B, C, D, E, F". , E, F, A, ... ”, and collect the data in this order. The PLC10 has, for example, "TorqueData1", "VelocityData1", "PositionData1", "TorqueData2", "VelocityData2", and "PositionData3" for each of the six I / O nodes in this order. Repeat the process of collecting. The PLC 10 repeats the process of collecting data of each I / O node one after another while switching the I / O nodes to be collected in a predetermined order, thereby displaying data indicating an abnormality of the control system 1. The possibility of overlooking (that is, leaking from the collection target) can be reduced.

(Arrangement of terms)
In the following description, "collecting data of each I / O node while switching the I / O nodes to be collected in a fixed order" may be referred to as "patrol". For example, "A, B, C, D, E, F (that is, A followed by B, B followed by C, C followed by D, D followed by E, E followed by F, F followed by A)". Collecting data of each I / O node by repeating in the pattern (order) of is sometimes referred to as "patrol".

The order sequence of I / O nodes, which is the minimum unit of circulation and does not include duplication of the appearance order of I / O nodes, may be referred to as "circulation unit order sequence (or simply" sequence ")". For example, when PLC10 executes a patrol with "A followed by B, B followed by C, C followed by A, A followed by B, B followed by C, C followed by A, A followed by B, ...". , The order is "A, B, C". Similarly, PLC10 is "A followed by B, B followed by C, C followed by D, D followed by E, E followed by F, F followed by A, A followed by B, B followed by C, and C followed by D. , D followed by E, E followed by F, F followed by A, A followed by B, ... ", the order is" A, B, C, D, E, F ".

The number of occurrences of a specific I / O node included in the patrol unit sequence is referred to as "patrol frequency". For example, the patrol frequency of "I / O node: A" in "sequential sequence: A, B, C, D, E, F" is "1 [round / round]". The patrol frequency of the "I / O node: A" in the "order: A, B, C, A, D, E, F" is "2 [rounds / rounds]". The patrol frequency of the "I / O node: A" in the "order: A, B, C, A, D, E, A, F" is "3 [rounds / rounds]".

The relative patrol frequency of "I / O nodes: A" in "sequential sequence: A, B, C, D, E, F" (the number of each I / O node with respect to the total number of elements in the sequential sequence) is determined. It may be expressed as "1/6 [times / round]". Similarly, the relative patrol frequency of "I / O node: A" in "order: A, B, C, A, D, E, F" is expressed as "2/7 [times / patrol]". You may. The relative patrol frequency of the "I / O node: A" in the "order: A, B, C, A, D, E, A, F" is "3/8 [rounds / rounds]".

As is clear from the above example, the number of I / O nodes included in the traveling unit sequence does not always match the total number of all elements in the traveling unit sequence, and the total number of elements in the traveling unit sequence is the traveling unit sequence. It changes depending on (patrol pattern). For example, even in the case of a "circular unit sequence (sequential sequence)" including six I / O nodes from A to F, the total number of all elements of the cyclic unit sequence varies. That is, the total number of all elements of "order: A, B, C, D, E, F" is "6", and the total number of all elements of "order: A, B, C, A, D, E, F" is The total number of all elements of "7" and "order: A, B, C, A, D, E, A, F" is "8".

Further, the patrol order in the patrol unit order sequence can be arbitrarily expressed according to the implementation. For example, a "sequential sequence: A, B, C" including three I / O nodes from A to C may be expressed as "sequential sequence: B, C, A" or "sequential sequence: C, A". , B "may be expressed.

Further, the patrol order (the appearance order of each I / O node) in the patrol unit order sequence can be arbitrarily set according to the implementation. For example, for the three I / O nodes from A to C, the order in which the total number of all elements is "3" is "Sequential: A, B, C" and "Sequential: A, C, B". Either may be set.

(Outline of PLC according to this embodiment)
In the control system 1, the user sets "a value indicating the magnitude of the processing load required for the execution of the sampling process by the PLC 10 and the maximum value allowed by the user" to "maximum allowable average sampling speed _{Vallowed_mean_max} (hereinafter, hereinafter,". Maximum value _Vamm ) ”. The PLC 10 dynamically optimizes the sampling rules for sampling based on the maximum value _Vamm .

That is, the user sets the maximum value _Vamm for the data collection capacity of the PLC 10, and sets a desired collection rule (reference value of the collection rule) for each I / O node. Specifically, for each I / O node, in addition to the "name (identifier)", the user sets "sampling frequency reference (reference frequency)" and "sampling" as desired collection rules for each I / O node. Specify the score standard (reference score), etc.

The "sampling score" is the number of data points collected for each I / O node for each occurrence in the cyclic unit sequence, and the "reference sampling score" is initially set by the user, that is, for example, of the user. The desired "sampling score".

The "sampling frequency" is the number of data points collected per unit time for each I / O node for each occurrence in the cyclic unit sequence. The "reference sampling frequency" is the "sampling frequency" that is initially set by the user, that is, that is, for example, the user desires.

PLC10 is a value (mean sampling speed) indicating the magnitude of the processing load required when the sampling process is executed according to the "collection rule at the time of initial setting" including the "reference frequency" and "reference point number" of each I / O node. _Vmean ) is calculated. Then, the PLC 10 compares the maximum value _Vamm with the average sampling rate V _mean , and specifically, "the difference between the maximum value V _amm and the average sampling rate V _mean (that is, the maximum value V _amm -mean sampling". The "margin velocity V _margin " is calculated from the "velocity V _mean ").

The PLC 10 adjusts the collection rule so that the margin speed V _margin is "0" or more (that is, the margin speed V _margin ≥ 0). Specifically, the PLC 10 has "circulation frequency (number of appearances)", "sampling frequency", and "sampling frequency" in the circulation unit sequence for each I / O node so that "margin speed V _margin becomes" 0 "or more". , Change at least one of the "sampling points". Further, the PLC 10 may adjust the "time required to make a round of the patrol unit sequence" so that the "margin speed V _margin becomes" 0 "or more". The PLC 10 starts sampling (data collection) according to a collection rule adjusted so that the margin speed V _margin becomes "0" or more.

Further, the PLC 10 determines the importance of the collected data for each I / O node, and specifically, for each I / O node (more accurately, for the data of each I / O node). Calculate the importance (evaluation value).

The PLC 10 is based on the result of the importance determination, that is, using the importance of each I / O node, within the range satisfying the condition that "the margin speed V _margin is" 0 "or more", each I / O. Adjust the collection rules for the nodes. Specifically, the PLC 10 has "patrol frequency" and "patrol frequency" in the patrol unit order based on the importance of each I / O node under the condition that "margin speed V _margin is" 0 "or more". Adjust at least one of "sampling frequency" and "sampling point". For example, the PLC 10 collects data in detail for high-importance I / O nodes, and avoids excessive data collection for low-importance I / O nodes. Adjust the collection rules for / O nodes according to the importance of each I / O node. Therefore, the PLC 10 can collect a large amount of highly important data in detail while making the best use of system resources.

(Note on importance)
The importance (evaluation value) for various data sampled by the PLC 10 differs depending on the purpose of use of the data, and the purpose of use varies depending on the user. For example, an operator may use the data to determine whether or not an "on-site abnormality" has occurred, and a line manager may use the data to determine "productivity and product quality". May be the main purpose of use. Also, if you are a maintenance person, the judgment of "signs of abnormality and bathtub curve" may be the main purpose of use of the data, and in particular, you are interested in the data acquired during the "before and after maintenance work" period. May be high. If you are an analyst, you may be very interested in the punctual (that is, acquired at regular intervals) data that you acquire "good / bad evenly", for example, the data that you acquire every four seasons. It may be expensive.

Since the importance (evaluation value) for data differs depending on the purpose of use, there is a contradiction between the importance of the same data from the viewpoint of one purpose of use and the importance of the same data from the viewpoint of another purpose of use. And can collide. For example, data that is less important to one purpose of use and may be deleted may be extremely important data that is essential for another purpose of use. ..

Therefore, the PLC 10 automatically arbitrates these plurality of "importances for each purpose of use" for each of the various sampled data, and assigns the "arbitrated importance" to each of the various sampled data. Specifically, the PLC 10 applies each of the plurality of evaluation methods corresponding to each of the plurality of purposes of use to each of the various sampled data, and calculates the importance of each evaluation method. Then, the PLC 10 calculates and calculates the arbitrated importance, which is the "importance corresponding to the entire plurality of evaluation methods", using the calculated importance of each evaluation method for each of the various sampled data. The arbitrated importance is given to each of the various sampled data. For each of the various sampled data, the PLC 10 uses, for example, the sum of the values indicating "importance for each evaluation method" multiplied by "weighting coefficient for each evaluation method" to determine the arbitrated importance. calculate. Further, in the PLC10, for each of the various sampled data, for example, the highest importance in the "importance for each evaluation method" is set as the arbitrated importance.

(About display processing, etc.)
The PLC 10 displays information related to the sampling process being executed on the display screen (for example, the display screen of an external display device such as a tool) so that the user can grasp the data collection status in real time and use it for problem finding. Is displayed. Specifically, the PLC 10 has "maximum value _Vamm set by the user", "average sampling rate _{Vmean indicating the magnitude of the processing load related to the sampling process during execution", and "maximum value Vamm and} average sampling". The margin speed V _margin , which is the difference from the speed V _mean , is displayed. Further, the PLC 10 has, for example, "the name of each of the plurality of I / O nodes included in the traveling unit sequence", "the appearance order of each I / O node in the traveling unit sequence", and "currently, the data collection target". "I / O node" is displayed. Further, the PLC 10 displays, for example, "sampling frequency", "sampling score", and "importance to the latest data" in the collection rule being applied for each I / O node.

As described above with reference to FIGS. 2 and 3, the PLC 10 repeats every control cycle, acquires control data from the slave device (that is, captures), and transmits the acquired control data to the database 20. Collect the data to be collected according to the collection rules. The PLC 10 collects data of each I / O node while sequentially switching the I / O nodes to be collected according to the cyclic unit order sequence defined as the collection rule. The PLC 10 adjusts the "circulation frequency", "sampling frequency", "sampling score", etc. of each I / O node defined as a collection rule so that the average sampling rate V _mean is the maximum value _Vamm or less. , Perform sampling according to the adjusted collection rules. Further, the PLC 10 calculates the importance of each I / O node (more accurately, about the data of each I / O node), and based on the calculated importance, the "patrol frequency" of each I / O node. , "Sampling frequency", "sampling point", etc.

(Organization of outline)
That is, the PLC 10 (master device) is a master device in the control system 1 which is a master-slave control system, and includes a collection unit 140, a reception unit 120, and a first adjustment unit 130. The collection unit 140 repeatedly collects each of a plurality of data to be transmitted to an external device such as the database 20 from the control data periodically acquired from the slave device such as the servo driver 30 according to a predetermined collection rule. The reception unit 120 receives the maximum value _Vamm specified by the user for the amount of data collected per unit time by the collection unit 140. The first adjusting unit 130 has the predetermined amount of data collected per unit time by the collecting unit 140 in accordance with the predetermined collecting rule so that the data amount is equal to or less than the maximum value _Vamm received by the receiving unit 120. Adjust collection rules.

According to the above configuration, the PLC 10 adjusts the predetermined collection rule so that the amount of data to be collected per unit time is not more than the maximum value _Vamm , and the control is performed according to the adjusted predetermined collection rule. From the data, each of the plurality of data is repeatedly collected.

Here, it is clear that the larger the amount of data to be collected per unit time, the larger the processing load per unit time related to the data collection of the PLC 10. That is, the maximum value _Vamm corresponds to the processing load per unit time related to the data collection of the PLC 10.

Therefore, the PLC 10 should transmit the control data to the external device of the database 20 so that the processing load per unit time related to data collection is equal to or less than the processing load corresponding to the maximum value _Vamm specified by the user. It has the effect of being able to collect data. In other words, the PLC 10 has an effect that the user can manage the processing load related to the process of collecting each of the plurality of data from the control data. Specifically, the user should transmit the PLC 10 to the database 20 with an appropriate processing load that does not affect the execution of "processing other than data collection processing such as control processing for the slave target such as the servo driver 30". Data can be collected from the control data.

Further, the "data amount of data collected by the PLC 10 per unit time" is easy for the user to intuitively grasp, and accurately indicates the "processing load of the PLC 10 per unit time related to data collection". It is an index that can be done.

Therefore, the PLC 10 is based on the "data amount of data to be collected per unit time" which is accurate as an index of "processing load per unit time related to data collection" and which is easy for the user to intuitively understand. It has the effect of being able to manage the data collection process.

In the PLC 10, the predetermined collection rule includes a sequence (circular unit sequence) indicating the collection order of each of the plurality of data collected by the collection unit 140. The collection unit 140 repeatedly collects each of the plurality of data according to the order. The amount of data collected per unit time by the collecting unit 140 in accordance with the predetermined collection rule is, for example, "the amount of data collected by the collecting unit 140 by the time the order is cycled, and the order is cycled. It is a value divided by the time required by the collecting unit 140 to do so. "

According to the above configuration, the PLC 10 repeats from the control data according to the order and collects each of the plurality of data to be transmitted to the external device such as the database 20.

Therefore, the PLC 10 has the effect that, for example, data for monitoring and verifying the control system 1 can be repeatedly collected from the control data in the collection order shown in the order.

In the PLC 10, the first adjusting unit 130 adjusts at least one of the following four as the predetermined collection rule. That is, the first adjusting unit 130 has (1) an appearance frequency which is the number of appearances of each of the plurality of data in the order, and (2) for each appearance of each of the plurality of data in the order. The number of sampling points, which is the number of data points to be collected, (3) the sampling frequency (collecting frequency), which is the number of data points collected per unit time for each appearance of each of the plurality of data in the sequence. (4) At least one of the times required by the collecting unit 140 to make a round of the order is adjusted.

According to the above configuration, as the predetermined collection rule, the PLC 10 has at least the frequency of appearance, the number of sampling points, the sampling frequency, and the time required to go around the sequence of each of the plurality of data. Adjust one.

Here, when "each of the plurality of data" at each of the plurality of time points is stored in an external device such as a database 20 and a consistent analysis is to be performed, the plurality of data is transmitted to the external device. It is desirable that the sampling frequency of each of the data in the above is invariant at each of the plurality of time points. For example, for a given data Da, if the sampling frequency at one time point T1 is 500 Hz, then the sampling frequency of that certain data Da at another time point T2 is consistent with respect to that certain data Da. If you want to perform a certain analysis, it is desirable to set it to 500 Hz. Therefore, for example, when collecting each of the plurality of data for the purpose of consistent analysis, the PLC 10 does not change the sampling frequency of each of the plurality of data when collecting each of the plurality of data. Adjust other items included in the prescribed collection rules. Specifically, the PLC 10 adjusts, as the predetermined collection rule, at least one of the frequency of appearance, the number of sampling points, and the time required to go around the sequence of each of the plurality of data.

Further, when it is desired to collect each of the plurality of data in a predetermined order evenly (that is, without being biased to a specific data), the PLC 10 changes the appearance frequency and the sampling point of each of the plurality of data. do not do. The PLC 10 adjusts at least one of the sampling frequency of each of the plurality of data and the time required to go around the sequence among the predetermined collection rules, and obtains the plurality of data from the control data. Collect each repeatedly.

Further, when it is not necessary to continuously collect each of the plurality of data (= collection period), the PLC 10 adjusts the time required to go around the sequence among the predetermined collection rules. For example, when the PLC10 repeatedly collects each data of "I / O node: A, B, C" according to "sequential sequence: A, B, C", the PLC 10 inserts free time (= waiting time) as follows. Then, the time required to "collect the data of each I / O node once in this order" is adjusted. That is, the PLC 10 is described as "from the end of data collection of" I / O node: A "to the start of data collection of" I / O node: B "" and "I / O node: B". From the end of data collection to the start of data collection of "I / O node: C" "and" After the end of data collection of "I / O node: C", "I / O node: Insert free time in at least one of "A" until the start of data collection.

That is, the PLC 10 adjusts at least one of the occurrence frequency, the number of sampling points, the sampling frequency, and the time required to go around the sequence of each of the plurality of data among the predetermined collection rules. Therefore, the PLC 10 appropriately adjusts the items suitable for the purpose of using the plurality of data among the predetermined collection rules, and the processing load related to the data collection becomes equal to or less than the processing load corresponding to the maximum value _Vamm . As described above, it has the effect of being able to collect the plurality of data.

When the importance (evaluation value) given to each of the plurality of data (that is, the data of each I / O node) collected by the collecting unit 140 meets a predetermined criterion, the PLC 10 has the predetermined value. It further comprises a second coordinator 160 that adjusts the rules for collecting data with a degree of importance that meets the criteria. The importance given to the data of each I / O node is, for example, the above-mentioned “arbitrated importance”.

The second adjusting unit 160 adjusts at least one of (1) the frequency of appearance, (2) the number of sampling points, and (3) the sampling frequency of the I / O node given the importance of satisfying a predetermined criterion. .. The first adjusting unit 130 further adjusts the collection rule including the appearance frequency, the number of sampling points, and the sampling frequency adjusted by the second adjusting unit 160 by using the maximum value _Vamm .

According to the above configuration, the PLC 10 adjusts at least one of the frequency of appearance, the number of sampling points, and the sampling frequency of each of the plurality of data according to the importance given to each of the plurality of data. do.

For example, PLC10 increases at least one value of frequency of occurrence, number of sampling points, and sampling frequency for data with high importance. The PLC 10 also reduces at least one value of frequency of occurrence, number of sampling points, and sampling frequency for data with low importance.

Therefore, the PLC 10 has the effect that each of the plurality of data can be collected at the appearance frequency, the number of sampling points, and the sampling frequency according to the respective importance.

Here, the PLC 10 further adjusts the collection rule including the appearance frequency, the number of sampling points, and the sampling frequency of each of the plurality of data adjusted according to the importance, using the maximum value _Vamm .

Therefore, the PLC 10 processes each of the plurality of data according to the respective importance, and the processing load per unit time related to the collection of each of the plurality of data corresponds to the maximum value _Vamm . It has the effect of being able to collect as follows.

In the PLC 10, the first adjusting unit 130 adjusts the collection rule by reducing at least one of the sampling points and the sampling frequencies of each of the plurality of data at a uniform rate using the reduction rate R.

According to the above configuration, for example, when the PLC 10 wants to collect each of the plurality of data in a predetermined order, the PLC 10 "the number of appearances of each of the plurality of data in the order" in the predetermined collection rule. Will not change. Instead, the PLC 10 reduces the processing load related to data acquisition by reducing at least one of the sampling points and the sampling frequencies of each of the plurality of data at a uniform rate using the reduction rate R.

Therefore, the PLC 10 performs a process related to data collection without changing "the number of appearances of each of the plurality of data in the order" when, for example, it is desired to collect each of the plurality of data in a predetermined order. It has the effect of reducing the load.

The PLC 10 has (1) the maximum value V _amm , (2) the amount of data collected per unit time by the collecting unit 140 according to the collecting rule adjusted by the first adjusting unit 130, and (3) the difference between the two. Further, a display control unit 170 for displaying the marginal speed V _margin , which is the above, to the user is provided.

According to the above configuration, the PLC 10 has an allowable value (that is, a maximum value _Vamm ) of the processing load related to data collection from the current processing load required for data collection so that the user can recognize at a glance. It has the effect of being able to notify the margin of up to.

In the PLC 10, each of the plurality of data collected by the collection unit 140 is data selected as a collection target by the user from the control data periodically acquired from the slave device such as the servo driver 30.

According to the above configuration, the PLC 10 repeatedly collects the data selected as the collection target by the user from the control data periodically acquired from the slave device such as the servo driver 30 according to the predetermined collection rule. ..

Therefore, the PLC 10 can repeatedly collect only the data selected as the collection target by the user among the control data so that the data amount of the data to be collected per unit time is not more than the maximum value _Vamm . It has the effect of.

The PLC10 whose outline has been described so far will be described first with reference to FIGS. 1 and 4, and then the processing executed by the PLC 10 will be described with reference to FIG. go.

§2. Configuration example (details of master device)
FIG. 1 is a block diagram showing a configuration of a main part such as PLC10. As shown in FIG. 1, the PLC 10 has an acquisition unit 110, a reception unit 120, a first adjustment unit 130, a collection unit 140, an evaluation unit 150, a second adjustment unit 160, and a display as functional blocks other than the storage unit 180. A control unit 170 is provided. In order to ensure the simplicity of the description, configurations that are not directly related to the present embodiment, such as a configuration in which a control instruction to the servo driver 30 is calculated and a configuration in which the calculated control instruction is output to the servo driver 30, are included. , Omitted from the description and block diagram. However, according to the actual situation of implementation, the PLC 10 may have the omitted configuration. Each functional block illustrated in FIG. 1 is, for example, in a storage device (storage unit 180) in which a CPU (central processing unit) or the like is realized by a ROM (read only memory), an NVRAM (non-Volatile random access memory), or the like. This can be realized by reading the stored program into a RAM (random access memory) (not shown) or the like and executing it. Hereinafter, each functional block in the PLC 10 will be described.

(Details of functional blocks other than the storage unit)
The acquisition unit 110 acquires control data output by the slave device from a slave device such as the servo driver 30 for each control cycle, and stores the acquired control data in the control data table 181 of the storage unit 180.

The reception unit 120 is a maximum value that is "the maximum value specified by the user regarding the amount of data collected by the PLC 10 per unit time from the control data" from a tool or the like connected to the PLC 10 via a communication cable. Accepts V _amm . The reception unit 120 stores the received maximum value _Vamm in the maximum allowable value table 182 of the storage unit 180.

The reception unit 120 also receives the "user's initial setting (reference value) for the collection rule to be followed when the PLC 10 executes the sampling process" from a tool or the like, and stores the received "collection rule initial setting". It is stored in the collection rule table 183 of 180. Specifically, the reception unit 120 has the "name (identifier)", "data type", "initial setting value of sampling frequency (reference frequency)", and "initial setting value of sampling points" of each I / O node. (Reference score) ”and the like are received, and these are stored in the collection rule table 183. Details of the "name (identifier)", "data type", "reference frequency", "reference point number", etc. stored in the collection rule table 183 will be described later in the description of FIG. In the present embodiment, the "reference frequency" is also referred to as a "reference sampling frequency", and the "reference point number" is also referred to as a "reference sampling point number".

The first adjusting unit 130 adjusts the collection rules to be followed when the PLC 10 executes the sampling process so that the processing load related to the sampling process executed by the PLC 10 is equal to or less than the maximum processing load allowed by the user.

(Adjustment using the maximum value _Vamm of the standard collection rule)
First, the first adjusting unit 130 refers to the collection rule table 183 exemplified in FIG. 4 and the like, and confirms that the "adjusted collection rule" is not yet stored in the collection rule table 183. Get the rule (that is, the collection rule at the initialization stage). The first adjusting unit 130 has input values in the items such as "ID", "name", and "data type" of the collection rule table 183, and in the items such as "actual frequency" and "actual score". If there is a line with no input value, it is determined that the "adjusted collection rule" is not stored.

When the first adjusting unit 130 determines that the "adjusted collection rule" is not stored, the "data type", "patrol frequency", "reference frequency", "reference point number", and the reference point number of each I / O node are stored. , Acquire a "standard collection rule" including "time required to complete a round of the patrol unit sequence".

Next, the first adjusting unit 130 calculates a value ( _mean sampling rate Vmean) indicating the magnitude of the processing load required when the PLC 10 executes the sampling process according to the reference collection rule. The method of calculating the _mean sampling rate Vmean from the reference collection rule will be described in detail later in the description of FIG. 7.

Then, the first adjusting unit 130 determines "whether the margin speed V _margin (= maximum value V _amm - _mean sampling speed V main) is" 0 "or more."

When the first adjusting unit 130 determines that the margin speed V _margin is "0" or more, the first adjusting unit 130 adopts the reference collecting rule as it is as the collecting rule to be followed when the PLC 10 actually executes the sampling process. .. That is, the first adjusting unit 130 stores the respective values of the "reference frequency" and the "reference point number" in the collection rule table 183 in each of the "actual frequency" and the "actual score" for each I / O node. do.

When the first adjusting unit 130 determines that "the margin speed V _margin is less than" 0 "", the first adjusting unit 130 adjusts the reference collecting rule, and collects the adjusted collecting rule according to when the PLC 10 actually executes the sampling process. Adopt as a rule. That is, the first adjustment unit 130 stores the collection rule adjusted so that "the margin speed V _margin is" 0 "or more" in the collection rule table 183. Specifically, for example, the first adjusting unit 130 transfers the value adjusted so that the margin speed V _margin is "0" or more to the "actual frequency" and "actual score" of the collection rule table 183. Store. Further, for example, the first adjusting unit 130 adjusts the patrol unit order sequence stored in the collection rule table 183 so that “the margin speed V _margin becomes“ 0 ”or more”. Further, for example, the first adjusting unit 130 adjusts the "time required to make a round of the patrol unit sequence" stored in the collection rule table 183 so that "the margin speed V _margin becomes" 0 "or more". do. The method of adjusting the collection rule by the first adjusting unit 130 will be described in detail later in the description of FIGS. 9 to 12.

(Re-adjustment of the adjusted collection rule using the maximum value _Vamm )
The first adjusting unit 130 refers to the collection rule table 183 exemplified in FIG. 4 and the like, and refers to the “real frequency” of the row in which the input values are in the items such as “ID”, “name”, and “data type”. And if there is an input value in an item such as "actual score", it is determined that the "adjusted collection rule" is stored. The first adjusting unit 130 calculates a value (mean sampling rate _Vmaan ) indicating the magnitude of the processing load of the sampling process according to the adjusted collection rule. The method of calculating the mean sampling rate V _mean from the adjusted collection rule is the same as the method of calculating the mean sampling rate V _mean from the reference collection rule.

Then, the first adjusting unit 130 determines "whether the margin speed V _margin (= maximum value V _amm - _mean sampling speed V main) is" 0 "or more."

When the first adjusting unit 130 determines that "the margin speed V _margin is" 0 "or more", it is stored in the collecting rule table 183 as a collecting rule to be followed when the PLC 10 actually executes the sampling process. Adopt the collection rules of No. without changing them. That is, the first adjusting unit 130 does not change the values stored in the respective items of the "real frequency" and the "real score" of the collection rule table 183 for each I / O node.

When the first adjusting unit 130 determines that "the margin speed V _margin is less than" 0 "", the adjusted collection rule is readjusted, and the PLC 10 actually executes the sampling process for the readjusted collection rule. Adopt as a collection rule to follow. That is, the first adjustment unit 130 stores the collection rule readjusted so that “the margin speed V _margin becomes“ 0 ”or more” in the collection rule table 183. Specifically, for example, the first adjusting unit 130 transfers the value readjusted so that the margin speed V _margin becomes "0" or more to the "actual frequency" and "actual score" of the collection rule table 183. And store. Further, for example, the first adjusting unit 130 adjusts the patrol unit order sequence stored in the collection rule table 183 so that “the margin speed V _margin becomes“ 0 ”or more”. Further, for example, the first adjusting unit 130 adjusts the "time required to make a round of the patrol unit sequence" stored in the collection rule table 183 so that "the margin speed V _margin becomes" 0 "or more". do. The method of adjusting the collection rule by the first adjusting unit 130 will be described in detail later in the description of FIGS. 9 to 12.

The collection unit 140 executes the sampling process according to the adjusted collection rule stored in the collection rule table 183, that is, refers to the control data table 181 and collects the data to be transmitted to the database 20. That is, the collection unit 140 collects the data of each I / O node while sequentially switching the I / O nodes to be collected according to the patrol unit order sequence stored in the collection rule table 183. At that time, the collecting unit 140 makes a round of the patrol unit sequence in the "time required to make a round of the patrol unit sequence" stored in the collection rule table 183. Further, the collecting unit 140 collects the data of each I / O node according to the "actual frequency" and the "actual score" of each I / O node stored in the collection rule table 183. Then, the collection unit 140 notifies the evaluation unit 150 of the data collected according to the collection rule adjusted by the first adjustment unit 130.

The evaluation unit 150 calculates the importance (for example, arbitrated importance) for the data of each I / O node collected by the collection unit 140 according to the adjusted collection rule stored in the collection rule table 183. , The calculated importance is stored in the collection rule table 183.

For example, the "I / O node: A" appearing at the beginning of the sequence collected by the collection unit 140 according to the "sequential sequence: A, B, C, A, D, E, F" stored in the collection rule table 183. The evaluation unit 150 calculates the importance of the above. The evaluation unit 150 stores the calculated importance in the item of "importance" of "I / O node: A" appearing at the head of the order in the collection rule table 183. Similarly, the "I / O" that appears fourth from the beginning of the sequence is collected by the collection unit 140 according to the "sequence: A, B, C, A, D, E, F" stored in the collection rule table 183. For "node: A", the evaluation unit 150 calculates the importance. The evaluation unit 150 stores the calculated importance in the item of "importance" of the "I / O node: A" that appears fourth from the beginning of the order in the collection rule table 183.

As described above, the evaluation unit 150 applies, for example, each of the plurality of evaluation methods corresponding to each of the plurality of purposes of use to the data of each I / O node, and calculates the importance of each evaluation method. Then, the evaluation unit 150 calculates the arbitrated importance, which is the "importance corresponding to the entire plurality of evaluation methods", using the calculated importance of each evaluation method, and determines the calculated arbitrated importance. It is stored in the item of "importance" of each I / O node in the collection rule table 183. The evaluation unit 150 uses, for example, the sum of the values indicating "importance for each evaluation method" multiplied by the "weighting coefficient for each evaluation method" for the data of each I / O node, and is arbitrated important. Calculate the degree. Further, the evaluation unit 150 sets the highest importance of the data of each I / O node in the "importance for each evaluation method" as the arbitrated importance.

Further, the evaluation unit 150 transmits the data of each I / O node notified from the collection unit 140 to the database 20, and stores these data in the collection data table 21.

The second adjusting unit 160 refers to the collection rule table 183, determines whether the "importance" of each I / O node in the collection rule table 183 meets a predetermined standard, and satisfies the predetermined standard. Change (adjust) the collection rule for the I / O node determined to be.

Specifically, the second adjusting unit 160 determines that the I / O node meets the predetermined criteria, the “real frequency”, the “real score”, and the “patrol frequency” of the collection rule table 183. To be precise, at least one item of "relative patrol frequency)" is updated. Details of the updated contents of the "actual frequency", the "actual score", and the "patrol frequency" by the second adjusting unit 160 will be described later with reference to FIG.

The display control unit 170 displays information related to the sampling process being executed on the display screen (for example, the display screen of an external display device such as a tool). The display control unit 170 includes, for example, a maximum value _Vamm set by the user, an average sampling rate _Vmean indicating the magnitude of the processing load related to the sampling process during execution, and a maximum value _Vamm and an average sampling rate _Vmean . The _margin speed V marin, which is the difference between the two, is displayed. Further, the display control unit 170 may, for example, "name each of the plurality of I / O nodes included in the patrol unit sequence", "the appearance order of each I / O node in the patrol unit sequence", and "currently, Display the "I / O node for which data is to be collected". Further, the display control unit 170 displays, for example, the “sampling frequency”, the “sampling point”, and the “importance to the latest data” in the collection rule being applied for each I / O node.

(Details of memory)
The storage unit 180 is a storage device that stores various data used by the PLC 10. The storage unit 180 executes (1) a control program executed by the PLC 10, (2) an OS program, (3) an application program for executing various functions of the PLC 10, and (4) the application program. Various data to be read at times may be stored non-temporarily. The data of (1) to (4) above may be, for example, ROM (read only memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), HDD (Hard Disc Drive), or the like. Stored in a non-volatile storage device. The PLC 10 may include a temporary storage unit (not shown). The temporary storage unit is a so-called working memory that temporarily stores data used for calculation and calculation results in the process of various processes executed by the PLC 10, and is composed of a volatile storage device such as a RAM (Random Access Memory). Will be done. Which data is stored in which storage device is appropriately determined from the purpose of use, convenience, cost, physical restrictions, and the like of the PLC 10. The storage unit 180 further stores the control data table 181 and the maximum allowable value table 182, and the collection rule table 183.

The control data table 181 stores the control data acquired by the acquisition unit 110 from the slave device for each control cycle by the acquisition unit 110. In the maximum allowable value table 182, the maximum value _Vamm received by the reception unit 120 is stored by the reception unit 120. The collection rule table 183 stores the collection rules and the like that the collection unit 140 follows when performing sampling, that is, the collection unit 140 refers to the control data table 181 and collects data to be transmitted to the database 20. Will be done.

(Overview of collection rule table)
FIG. 4 is a diagram showing an example of the data structure of the collection rule table 183. As illustrated in FIG. 4, in the collection rule table 183, for example, the IDs that identify each I / O node are stored in the order of appearance in the patrol unit sequence, that is, in the collection rule table 183, the patrol is performed. A unit sequence is stored. In other words, the I / O nodes corresponding to the IDs stored in the "ID" item of the collection rule table 183 are stored in the "ID" item of the collection rule table 183 (for example, in FIG. 4). Data will be collected from the top of the page). In the example of FIG. 4, the patrol unit sequence of "sequential sequence: A, B, C, D, E, F, ..., X" is specified in the collection rule table 183. That is, in the collection rule table 183 exemplified in FIG. 4, "A is followed by B, B is followed by C, C is followed by D, D is followed by E, E is followed by F, F is followed by ..., and X is followed by. The patrol unit order sequence with "A" is stored.

In the description of the present embodiment, for the sake of simplification, for example, the I / O node of "ID: A" is referred to as "I / O node: A" and the I / O node of "ID: B" is referred to as "I / O node". It may be abbreviated as "I / O node: B".

As initial settings, the user uses, for example, a "name" indicating what kind of data the I / O node corresponding to each ID is about, and a standard of the size of the data per unit. Register the "data type". The user registers the size of the data to be collected per unit for each I / O node by registering the "data type" for each I / O node.

In addition, the user registers a collection rule for each I / O node as an initial setting. That is, the user registers the "reference frequency" as the initial setting of the sampling frequency and the "reference point number" as the initial setting of the sampling points for each I / O node. Further, the user may register an "importance variable" which is an item indicating the variable name of the importance given to each I / O node.

The reception unit 120 receives the "name (identifier)", "data type", "reference frequency", "reference score", etc. registered by the user for each I / O node, and corresponds to these in the collection rule table 183. Store in the item to be.

In the example of FIG. 4, the user registers "TorqueData1 (for example, torque of the shaft 1)" as the "name" of the I / O node of "ID: A", and also I of "ID: A". It is shown that the "data type" of the data in the / O node is "INT" type. The "reference frequency (that is, the preset sampling frequency)" of the I / O node of "ID: A" is "200 Hz", and the "reference point number (that is, the preset sampling point number)" is ". 1000 ".

Similarly, the user registers "Velocity Data1 (for example, the speed of the axis 1)" as the "name" of the I / O node of "ID: B", and also the I / O node of "ID: B". It is shown that the "data type" of the data in is "DINT" type. The "reference frequency" of the I / O node of "ID: B" is "200 Hz", and the "reference point number" is "1000".

(Note on waiting time setting)
As described above, the collection unit 140 executes the patrol according to the patrol unit sequence stored in the collection rule table 183. Here, the details will be described later with reference to FIG. 12B, but the collecting unit 140 may set a waiting time between the data to be sampled. For example, in the collection rule table 183 illustrated in FIG. 4, there may be a row in which data is stored only in the items of “ID” and “collection time (not shown in FIG. 4)”. That is, the collection rule table 183 shows the collection time (sampling period) for each occurrence in the circulation unit sequence for each I / O node (more accurately, “each ID”) in the circulation unit sequence. It may have an item of "time".

For example, for the row of "ID: D" in the collection rule table 183 that stores "sequential columns: A, B, C, D", items such as "reference frequency" and "reference score" are not specified, and "collection time" is not specified. When "10.7s" is stored only in the item "", the following collection rules are stored in this collection rule table 183. That is, "10.7 seconds" from the completion of sampling (that is, data collection) for the "ID: C" I / O node to the start of sampling for the "ID: A" I / O node. During that time, a collection rule for interrupting the sampling process is stored. In this embodiment, "second" may be abbreviated as "S".

If "waiting time" is set (inserted) during sampling of multiple I / O nodes, only the "ID" and "collection time" items of the I / O node set as "waiting time" Is set, and items such as "reference frequency" and "reference score" are not specified. However, for the I / O node set as the "waiting time", "reference score: 0" and "actual score: 0" may be set in the collection rule table 183.

(About importance)
As described above, the collection unit 140 collects the data of the I / O nodes corresponding to the IDs appearing in sequence in the patrol unit sequence one after another, and the evaluation unit 150 collects the data collected by the collection unit 140. Gives importance (arbitrated importance). Specifically, the evaluation unit 150 stores the importance given to the data collected by the collection unit 140 in the "history" item of the collection rule table 183.

In the collection rule table 183, "N" is an integer of "1" or more, and in each of the cyclic unit sequence from the first round to the Nth cycle, the I / O node corresponding to the ID appearing in each cyclic unit sequence is used. It has N "history" items that store the importance given to the data. In the N "history", the importance given in each of the cyclic unit sequence from the first round to the Nth round is stored in, for example, FIFO (First --In First --Out), in other words, the importance. The history of the past N times is stored. The example shown in FIG. 4 is an example of “N = 6”, that is, the collection rule table 183 of FIG. Has six "history" items from "history 1" to "history 6" in which is stored.

For example, when the collection rule table 183 stores "sequential columns: A, B, C, A, D, E, F", the "history" item of the collection rule table 183 in FIG. 4 is as follows. The importance given by the collecting unit 140 is stored in.

That is, when the evaluation unit 150 calculates the "importance: 2" for the "I / O node: A" at the head of the first round of the patrol unit sequence, the head "ID: A" in the collection rule table 183 is calculated. Store "importance: 2" in "history 1". When the evaluation unit 150 calculates "importance: 1" for the "I / O node: A" that appears fourth from the beginning of the first round of the circulation unit sequence, it becomes the fourth from the beginning in the collection rule table 183. "Importance: 1" is stored in "History 1" of "ID: A" that appears.

When the evaluation unit 150 calculates "importance: 3" for the "I / O node: A" at the head of the second round of the patrol unit sequence, the "history" of the head "ID: A" in the collection rule table 183. "Importance: 3" is stored in "1", and "importance: 2" is stored in "History 2". When the evaluation unit 150 calculates the "importance: 2" for the "I / O node: A" that appears fourth from the beginning of the second round of the patrol unit sequence, it becomes the fourth from the beginning in the collection rule table 183. "Importance: 2" is stored in "History 1" of the appearing "ID: A", and "Importance: 1" is stored in "History 2".

(About other items)
The collection rule table 183 illustrated in FIG. 4 is based on the "ID", "name", "data type", "reference frequency", "reference score", "importance variable", and "history 1" described so far. In addition to "History 6" and "Collection time", it has the following items. That is, the collection rule table 183 has items of "real frequency (also referred to as" real sampling frequency ")" and "real score (also referred to as" real sampling score ")". Details of the "real frequency" and the "real score" will be described later with reference to FIGS. 6 to 8 and the like.

§3. Operation Example FIG. 5 is a flow chart showing an outline of the processing executed by the PLC 10. The reception unit 120 receives the maximum value _Vam specified by the user from a tool or the like, and stores the received maximum value _Vam in the maximum allowable value table 182 of the storage unit 180 (S110).

In addition, the reception unit 120 sets initial settings (reference values) for collection rules such as "data type", "reference frequency", and "reference score" specified by the user for each I / O node from a tool or the like. accept. The reception unit 120 stores the received "initial setting of the collection rule" in the collection rule table 183 of the storage unit 180. That is, the reception unit 120 is assigned to make a round of the "name (identifier)", "data type", "reference frequency", "reference score", "patrol frequency", and "circular sequence" of each I / O node. The initial value of "the determined period" is set (S120).

At the initial setting stage, the "patrol frequency" of each I / O node is assumed to be, for example, "once" in the patrol unit order sequence. That is, the cyclic unit sequence in which all the I / O nodes selected by the user as the "data collection target" appear only once is stored in the collection rule table 183 as the cyclic unit sequence in the initial setting stage, and each I / The "patrol frequency" of the O node is "1" at the initial setting stage. Further, the "period allocated to make a round of the sequence" will be described in detail later, but is calculated from the cycle unit sequence, the sampling frequency, and the number of sampling points.

In the first adjusting unit 130, the average sampling rate _Vmean indicating the processing load related to the sampling process executed by the collecting unit 140 according to the collection rule stored in the collection rule table 183 indicates the maximum processing load allowed by the user. It is determined whether the value is less than or equal to V _amm . That is, the first adjusting unit 130 determines whether or not the “mean sampling speed V _mean <= maximum value V _amm ” is set (S130). The first adjusting unit 130 calculates the mean sampling rate V _mean from the adjusted collection rule if the adjusted collection rule has been stored with reference to the collection rule table 183, and the adjusted collection rule is not stored. If so, the _mean sampling rate Vmean is calculated from the reference collection rule. Then, the first adjusting unit 130 determines whether the calculated average sampling rate _{Vmean is equal to or less than the maximum value Vamm stored} in the maximum permissible value table 182.

When the first adjusting unit 130 determines that the average sampling rate _{Vmean is equal to or less than the maximum value Vamm (} Yes in S130), the collection rule stored in the collection rule table 183 is collected as it is, and the collection unit 140 should follow. Adopt as a rule. That is, if the adjusted collection rule is not stored, the first adjustment unit 130 sets the respective values of the "reference frequency" and the "reference point score" of the collection rule table 183 for each I / O node to "actual". Store in each of "frequency" and "actual score". If the adjusted collection rule has already been stored, the first adjustment unit 130 will use the values stored in the "real frequency" and "real score" items of the collection rule table 183 for each I / O node. Do not change.

The collection unit 140 refers to the control data table 181 and executes data collection according to the collection rules stored in the collection rule table 183 (S150). That is, the collection unit 140 collects the data of each I / O node in the collection rule table 183 while switching the I / O nodes to be collected according to the patrol unit sequence stored in the collection rule table 183. Collect according to "frequency" and "actual score".

When the first adjusting unit 130 determines that the average sampling rate _{Vmean is larger than the maximum value Vamm (} No in S130), the collection rule stored in the collection rule table 183 is adjusted (or readjusted) for collection. The rule is adopted as the collection rule to be followed by the collection unit 140. That is, the first adjusting unit 130 makes a round of the "patrol frequency (more accurately, the relative patrol frequency)", "sampling frequency", "sampling point", and "sequential sequence" of each I / O node. At least one of the "allocated periods" is corrected (adjusted) using the maximum value _Vamm (S140). The first adjusting unit 130 makes a round of the "circulation frequency", "sampling frequency", "sampling point", and "sequential sequence" of each I / O node so that the average sampling speed V _mean is equal to or less than the maximum value _Vamm . Adjust at least one of the "durations allotted to".

If the adjusted collection rule is not stored, for example, the first adjustment unit 130 sets the adjusted value of at least one of the "reference frequency" and the "reference point" in the collection rule table 183 as the "actual frequency". And store in "actual score". Further, the first adjusting unit 130 adjusts, for example, the patrol unit sequence stored in the collection rule table 183, and further, for example, it takes to make a round of the “circulation unit sequence” stored in the collection rule table 183. Adjust the time.

If the adjusted collection rule is already stored, the first adjustment unit 130 determines the "actual frequency" and "actual score" of the collection rule table 183 so that the average sampling rate _{Vmean is equal to or less than the maximum value Vamm .} Readjust at least one of the values. Further, the first adjusting unit 130 readjusts, for example, the patrol unit sequence stored in the collection rule table 183, and further, for example, by the time the patrol unit sequence stored in the collection rule table 183 is cycled. Readjust "Time required".

The collection unit 140 executes data collection (sampling) with reference to the control data table 181 according to the adjusted (or readjusted) collection rule in S140 stored in the collection rule table 183 (S150). .. The collection unit 140 notifies the evaluation unit 150 of the data of each I / O node collected according to the collection rules stored in the collection rule table 183.

The evaluation unit 150 calculates the importance (arbitrated importance) for the data of each I / O node notified from the collection unit 140, and the calculated importance is the corresponding I / in the collection rule table 183. Store in the "History (history of importance)" item of the O node.

The second adjusting unit 160 refers to the collection rule table 183, determines whether the "importance" of each I / O node in the collection rule table 183 meets a predetermined standard, and satisfies the predetermined standard. Adjust the collection rules for the I / O nodes that are determined to be. That is, the second coordinating unit 160 determines the “patrol frequency (more accurately, relative patrol frequency)” of each I / O node in the collection rule table 183, based on the importance of each I / O node. At least one value of "sampling frequency" and "sampling point" is updated (S160).

The processes executed by the PLC 10 (in other words, the control method executed by the PLC 10) described so far with reference to FIG. 5 can be organized as follows. That is, the control method executed by the PLC 10 is a control method of the PLC 10 (master device) in the control system 1 which is a master-slave control system, and is a collection step (S150), a reception step (S110), and a first adjustment step. (S140) and. The collection step S150 is a step of repeatedly collecting each of a plurality of data to be transmitted to an external device such as the database 20 from the control data periodically acquired from the slave device such as the servo driver 30 according to a predetermined collection rule. be. The reception step S110 is a step of receiving the maximum value _Vamm specified by the user for the data amount of the data collected per unit time in the collection step S150. In the first adjustment step S140, the data amount of the data collected per unit time in the collection step S150 according to the predetermined collection rule is equal to or less than the maximum value _Vamm received in the reception step S110. It is a step to adjust the collection rules.

According to the above method, the control method executed by the PLC 10 adjusts the collection rule so that the amount of data to be collected per unit time is the maximum value _Vamm or less, and the control data is in accordance with the adjusted collection rule. From, each of the plurality of data is repeatedly collected.

Here, it is clear that the larger the amount of data to be collected per unit time, the larger the processing load per unit time related to the data collection of the control method executed by the PLC 10. That is, the maximum value _Vamm corresponds to the processing load per unit time related to the data collection of the control method executed by the PLC 10.

Therefore, the control method executed by the PLC 10 is to obtain the database 20 or the like from the control data so that the processing load per unit time related to data collection is equal to or less than the processing load corresponding to the maximum value _Vamm specified by the user. It has the effect of being able to collect data to be transmitted to an external device. In other words, the control method executed by the PLC 10 has an effect that the user can manage the processing load related to the process of collecting each of the plurality of data from the control data. Specifically, the user transmits the PLC 10 to the external device with an appropriate processing load that does not affect the execution of "processing other than data collection processing such as control processing for the slave target such as the servo driver 30". The data to be output can be collected from the control data.

Further, the "data amount of data collected by the control method executed by the PLC 10 per unit time" is easy for the user to intuitively understand, and "the control method executed by the PLC 10 per unit time related to data collection". It is an index that can accurately indicate the processing load of.

Therefore, the control method executed by the PLC 10 is accurate as an index of "processing load per unit time related to data collection" and is easy for the user to intuitively understand "the amount of data collected per unit time". It has the effect of being able to manage the data collection process based on.

(Regarding the adjustment of collection rules for each I / O node based on importance)
FIG. 6 is a diagram illustrating a specific example of a method of adjusting the collection rule based on the importance of each I / O node. FIG. 6A is a diagram showing an example of a method of adjusting the sampling frequency and the number of sampling points based on the importance. FIG. 6B adjusts the patrol frequency of each I / O node (more accurately, the relative patrol frequency) based on the importance, that is, adjusts the patrol unit order according to the collection unit 140. It is a figure which shows an example of the method.

(Adjustment of at least one of sampling frequency and sampling point)
With "N" as an integer of "1" or more, in the second adjustment unit 160, the value stored in the "history (history of importance)" of the collection rule table 183 is continuously increased N times, and the reference value is increased. Change the collection rule of I / O nodes (that is, each ID) that are Uth or higher.

FIG. 6A shows an example in which “N = 6” and “increase reference value Uth = 3”. In (A) of FIG. 6, a value of "3" or more is input to each of "History 1" to "History 6" of "I / O node: A", that is, "I". For "/ O node: A", the value stored in the "history" is continuously "6" times, and the increase reference value is "3" or more. Therefore, the second adjustment unit 160 increases the "real frequency" of the "I / O node: A" from "200 Hz to 400 Hz" and increases the "real score" from "1000 to 2000". There is. However, it is not essential for the second adjusting unit 160 to increase both the "real frequency" and the "real score" values, and at least one of the values may be increased. The second adjustment unit 160 adjusts the collection rule of the I / O node for the data of high importance, specifically, increases at least one of the sampling frequency and the sampling point. , Collect more data.

With "M" as an integer of "1" or more, in the second adjustment unit 160, the value stored in the "history (history of importance)" of the collection rule table 183 is continuously reduced M times. Change the collection rule of I / O nodes (that is, each ID) that are Dth or less.

FIG. 6A shows an example in which “M = 6” and “decrease reference value Dth = 1”. In (A) of FIG. 6, a value of "1" or less is input to each of "History 1" to "History 6" of "I / O node: D", that is, "I". For "/ O node: D", the value stored in the "history" is continuously "6" times, and is equal to or less than the reduction reference value "1". Therefore, the second adjustment unit 160 reduces the "real frequency" of the "I / O node: D" from "200 Hz to 100 Hz" and the "real score" from "1000 to 500". There is. However, it is not essential for the second adjusting unit 160 to reduce both the "real frequency" and the "real score" values, and at least one of the values may be reduced. The second adjustment unit 160 adjusts the collection rule of the I / O node of the less important data, specifically, reduces at least one of the sampling frequency and the sampling point. , Suppress the amount of data collected.

(Adjustment of patrol frequency)
With "N" as an integer of "1" or more, the second adjusting unit 160 determines that the value stored in the "history" of the collection rule table 183 is N times in succession and is equal to or greater than the increase reference value Uth. Increases the patrol frequency (more precisely, the relative patrol frequency) of the O-node (ie, each ID). Further, in the second adjusting unit 160, where "M" is an integer of "1" or more, the value stored in the "history" of the collection rule table 183 is continuously M times or less than the reduction reference value Dth. Decrease the patrol frequency (more precisely, the relative patrol frequency) of the I / O node (ie, each ID). That is, the second adjusting unit 160 changes the relative patrol frequency of each I / O node based on the importance of each I / O node, that is, changes the patrol unit sequence.

In the first stage of (B) of FIG. 6, when the IDs of the I / O nodes for which data is collected are six, A, B, C, D, E, and F, a normal patrol unit sequence (that is,). , Circular unit order sequence in the initial setting stage), specifically, "sequential sequence: A, B, C, D, E, F" is shown. In the initial setting stage, the "patrol frequency" of each I / O node is "1", and therefore, the IDs of the I / O nodes for which data is collected are six, A, B, C, D, E, and F. In the case of, the patrol unit order sequence in the initial setting stage is, for example, "sequential sequence: A, B, C, D, E, F". The collecting unit 140 says, "A is followed by B, B is followed by C, C is followed by D, D is followed by E, E is followed by F, F is followed by A, A is followed by B, B is followed by C, and C is followed by D. , D followed by E, E followed by F, F followed by A, A followed by B, ... ”.

In the second row of (B) in FIG. 6, the patrol unit order sequence when the patrol frequency of "I / O node: A" is increased with "N = 6" and "increase reference value Uth = 3" is shown. It is shown. Like "I / O node: A" in (A) of FIG. 6, a value of "3" or more is input to each of "History 1" to "History 6", that is, the value of "History" is When the number of times is continuously "6" times and the increase reference value is "3" or more, the second adjusting unit 160 increases the patrol frequency of "I / O node: A". The "sequential sequence: A, B, C, A, D, E, F" shown in the second row of FIG. 6 (B) is the "sequential sequence: A, B, C" shown in the first row of FIG. 6 (B). , D, E, F ”, only for“ I / O node: A ”is an example of a patrol unit order sequence when the patrol frequency is increased. In the "order: A, B, C, A, D, E, F", the "patrol frequency" of the "I / O node: A" is "2", and the other I / O node (that is, B, The "patrol frequency" of C, D, E, F) is "1". The second coordinating unit 160 adjusts the collection rule of the I / O node of the data of high importance, specifically, increases the relative patrol frequency, and more. Collect data.

In the third row of (B) in FIG. 6, the patrol unit order sequence when the patrol frequency of "I / O node: D" is increased with "M = 6" and "decrease reference value Dth = 1" is shown. It is shown. Like "I / O node: D" in (A) of FIG. 6, a value of "1" or less is input to each of "History 1" to "History 6", that is, the value of "History" is When the number of times is continuously "6" times and the reduction reference value is "1" or less, the second adjusting unit 160 reduces the patrol frequency of "I / O node: D". The "order: A, B, C, A, E, F, A, B, C, A, D, E, F" shown in the third row of FIG. 6 (B) is that of FIG. 6 (B). This is an example of a patrol unit sequence when the patrol frequency of "I / O node: D" is reduced from "sequential sequence: A, B, C, A, D, E, F" shown in the second row. In the "order: A, B, C, A, E, F, A, B, C, A, D, E, F", the "patrol frequency" is "4" for "I / O node: A". "I / O node: B, C, E, F is" 2 "," I / O node: D "is" 1 ". The second coordinating unit 160 adjusts the collection rule of the I / O node of the less important data, specifically, reduces the relative patrol frequency, and collects the data. Suppress the amount.

(Specific example of adjustment of collection rule using maximum value _Vamm )
It is most desirable if the acquisition unit 110 can collect all the control data acquired from the slave device for each control cycle, that is, the data of all the I / O nodes according to the collection rules in the initial setting stage. The processing load of such collection processing becomes extremely large. Therefore, the user sets the allowable maximum value of the "processing load related to the sampling process executed by the PLC 10 (in other words, the" data collection capacity of the system ")" as the "maximum value _Vamm ", and performs the sampling process on the PLC 10. Manage the processing load.

The first adjusting unit 130 follows a collection rule when the collecting unit 140 executes the sampling process so that the processing load related to the sampling process by the collecting unit 140 is equal to or less than the processing load specified by the “maximum value _Vamm ”. To adjust. Specifically, the first adjustment unit 130 has at least one of the “patrol frequency”, “sampling frequency”, “sampling point”, and “time required to complete the patrol unit sequence” of each I / O node. Adjust one item using the maximum value _Vamm .

Whether the first adjusting unit 130 adjusts the "patrol frequency", "sampling frequency", "sampling point", or "time required to complete the patrol unit sequence" of each I / O node is determined. For example, it is determined by the purpose of use of the data collected by the collecting unit 140. For example, when the PLC 10 is made to execute the data collection process (that is, the sampling process) for the purpose of "consistent analysis" for the data collected by the collection unit 140, the "sampling frequency" in the collection rule is unchanged. Is desirable. Therefore, for example, the first adjusting unit 130 changes (adjusts) at least one of the “patrol frequency” and the “sampling point”, and keeps the “sampling frequency” unchanged (frequency maintenance).

For example, when the purpose is to have the collection unit 140 collect data evenly from "all control data acquired by the acquisition unit 110 from the slave device at each control cycle", the "patrol frequency" and "patrol frequency" in the collection rules It is desirable that the "sampling score" is invariant. Therefore, for example, the first adjusting unit 130 changes (adjusts) the "sampling frequency" and keeps the "patrol frequency" and the "sampling score" unchanged (patrol frequency and score maintenance). If it is permissible for the sampling unit 140 to interrupt the sampling process to be repeatedly executed, the first adjusting unit 130 provides a waiting time between the sampling processes to be repeatedly executed, that is, "until the cycle unit sequence is cycled. Adjust the "time required" (waiting time insertion).

The first adjusting unit 130 makes the processing load related to the sampling process less than or equal to the processing load specified by the "maximum value _Vamm " by any method according to the purpose of use of the data collected by the collecting unit 140. In addition, adjust the collection rules. That is, the first adjusting unit 130 collects so that the value (mean sampling speed _{Vmean) indicating the magnitude of the processing load of the data collecting process (sampling process) executed by the collecting unit 140 is equal to or less than the maximum value Vamm .} The collection rules are adjusted according to the purpose of use of the data collected by 140.

Hereinafter, first, using FIGS. 7 and 8, the first adjusting unit 130 _{sets a value (mean sampling rate Vmean) indicating the magnitude of the processing load of the sampling process executed by the collecting unit 140, and a maximum value V amm .} The method for determining the necessity of adjusting the collection rule will be described.

(Example when adjustment of collection rules is not necessary)
FIG. 7 is a diagram showing an example of a collection rule table 183 or the like when the reference collection rule can be adopted without changing the reference collection rule as the collection rule to be followed when the collection unit 140 actually executes the sampling process. In FIG. 7, “maximum value _Vamm = 1024byte / s” is set.

The user acquires control data from the slave device for each control cycle by the acquisition unit 110, which is control data stored in the control data table 181 such as "I / O node: A", "I / O node: B", and , Register the following contents for the data of "I / O node: C". That is, the user sets a "name", a "data type", a "reference frequency", and a "reference point" for each I / O node. Here, the "data type" is, for example, "INT", "DINT", etc., as illustrated in FIG. 4, and is information indicating the size of the data of each I / O node per unit. For example, it is assumed that the size of the data of "data type: INT" per unit is "16 bits", and the size of the data of "data type: DINT" per unit is "32 bits".

In the collection rule table 183 exemplified in FIG. 7A, for "I / O node: A", the "data type" is, for example, "DINT", the unit is 32 bits, and the "reference frequency" is "reference frequency". Information that "200 Hz" and "reference point" are "1000" is registered. Similarly, for "I / O node: B", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "200 Hz", and the "reference point number" is "1000". .. Further, in the "I / O node: C", the "data type" is, for example, "INT", 16 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000".

(Calculation method of sampling speed)
The first adjusting unit 130 collects data per unit time (1 second) for each I / O node from the "data type", "reference frequency", and "reference point number" of each I / O node. The sampling rate V _sample indicating "data amount (byte)" is calculated. Assuming that the sampling speeds V _sample of "I / O node: A", "I / O node: B", and "I / O node: _C " are sampling speeds V _A , V _B , and VC, respectively. The first adjusting unit 130 calculates the sampling speeds V _A , V _B , and _VC as follows. That is, for each I / O node, the first adjustment unit 130 multiplies the size per unit of data specified by the "data type" by the value of the "reference frequency", and then uses "8 bits / byte". Divide to calculate the sampling rate V _sample . The sampling rates V _A , V _B , and _VC are, specifically, as illustrated in FIG. 7 (B), respectively.

Will be.

That is, for each I / O node, the first adjustment unit 130 multiplies the size per unit of data specified by the "data type" by the value of the "sampling frequency", and then uses "8 bits / byte". Divide to calculate the sampling rate V _sample .

(Calculation method of collection time)
In addition, the first adjustment unit 130 describes the "period required to collect the reference points" for each I / O node from the "data type", "reference frequency", and "reference point number" of each I / O node. The collection time T _sample is calculated. Assuming that the collection time T _sample of each of "I / O node: _A ", "I / O node: _B ", and "I / O node: C" is collection time TA, TB, and _TC , The first adjusting unit 130 calculates the collection times _TA , _TB , and _TC as follows. That is, the first adjusting unit 130 calculates the collection time T _sample by dividing the value of the “reference point” by the value of the “reference frequency” for each I / O node. The collection times _TA , _TB , and _TC are, specifically, as illustrated in FIG. 7 (B), respectively.

Will be.

That is, the first adjustment unit 130 calculates the collection time T _sample by dividing the value of the “sampling point” by the value of the “sampling frequency” for each I / O node. In the following description, "total collection time T _sample of each I / O node, total for all I / O nodes (that is, total collection time T _sample for all I / O nodes)" is referred to as "total collection time T." Sometimes referred to as " _All ". The total collection time T _All can be said to be the period allocated for the first adjusting unit 130 to make a round of the traveling unit sequence (in other words, the period required for the collecting unit 140 to make a round of the traveling unit sequence). In the example shown in FIG. 7B, the total collection time T _All = _TA + _TB + _TC = 5 + 5 + 1 = 11s is obtained from the total collection time T _sample of each I / O node in the cyclic unit sequence.

(Calculation method of average sampling rate)
The first adjustment unit 130 indicates the amount of data collected per unit time by the collection unit 140 from the sampling speed V _sample and the collection time T _sample calculated for each I / O node in the cyclic unit sequence. "Sampling speed V _mean " is calculated. Specifically, the first coordinating unit 130 "determines the amount of data collected by the collecting unit 140 before making a round of the traveling unit sequence, at the time interval required by the collecting unit 140 to make a round of the traveling unit sequence. The "average sampling rate V _mean " is calculated as the "divided value". For example, the first adjusting unit 130 sets the total of all I / O nodes of "a value obtained by multiplying the sampling rate V _sample of each I / O node by the collection time T _sample of each I / O node". The average sampling rate _Vmean is calculated by dividing by the total collection time T _sample for the O node. Specifically, the average sampling rate V _mean is as illustrated in FIG. 7 (B).

Will be.

(Calculation method of margin speed)
The first adjusting unit 130 calculates the "margin speed V _margin " as a value obtained by subtracting the average sampling speed V _margin from the maximum value V _amm . Since "maximum value V _am = 1024 bytes / s" and "mean sampling rate V _mean = 910 bytes / s", as illustrated in FIG. 7 (B),

Is.

When the first adjusting unit 130 confirms that "margin speed V _margin = 114byte / s", that is, "margin speed V _margin is" 0 "or more", it is determined that adjustment of the collection rule is unnecessary. do. For each I / O node, the first adjusting unit 130 stores the respective values of the “reference frequency” and the “reference point number” in the collection rule table 183 in each of the “actual frequency” and the “actual score”.

That is, as illustrated in FIG. 7 (C), the first adjusting unit 130 has "200 Hz", which is equal to the "reference frequency" in the "actual frequency" of the "I / O node: A" in the collection rule table 183. Is stored, and "1000" equal to the "reference score" is stored in the "actual score". Similarly, for the "I / O node: B", "200 Hz" equal to the "reference frequency" is stored in the "real frequency", and "1000" equal to the "reference score" is stored in the "real score". Further, for the "I / O node: C", "1000 Hz" equal to the "reference frequency" is stored in the "real frequency", and "1000" equal to the "reference score" is stored in the "real score".

The collection unit 140 executes sampling processing according to the adjusted collection rule stored in the collection rule table 183, that is, the “reference frequency” and “reference frequency” of each I / O node stored in the collection rule table 183. Sampling is performed according to the "score". Specifically, since the collection rule table 183 exemplified in FIG. 7 (C) stores "sequential columns: A, B, C", the collection unit 140 has "I / O node: A". , "I / O node: B", and "I / O node: C" are collected in this order. The collection unit 140 collects data of "sampling points: 1000" with "sampling frequency: 200 Hz" for "I / O node: A". The collection unit 140 collects data of "sampling points: 1000" with "sampling frequency: 200 Hz" for "I / O node: B". The collection unit 140 collects data of "sampling points: 1000" points as "sampling frequency: 1000 Hz" for "I / O node: C".

(Notes on sampling speed)
In the example shown in FIG. 7, the sampling rate VC of the “I / O node: _C ” is “2000 bytes / s”, which is larger than the “maximum value _Vamm = 1024 bytes / s”. However, since the "mean sampling rate Vmean = 910byte / s" is equal to or less than the "maximum value V _amm = _1024byte / s", the first adjusting unit 130 determines that the collection rule does not need to be adjusted.

That is, even if the sampling speed V _sample of a specific I / O node exceeds the maximum value _Vamm , if the average of the entire data collection (mean sampling speed V _mean ) is equal to or less than the maximum value _Vamm , the first adjustment unit 130 determines that adjustment of the collection rules is not necessary.

(Example when it is necessary to adjust the collection rules)
FIG. 8 is a diagram showing an example of a collection rule table 183 or the like when the reference collection rule cannot be adopted as it is as the collection rule to be followed when the collection unit 140 actually executes the sampling process. In FIG. 8, “maximum value _Vamm = 1024byte / s” is set.

In the collection rule table 183 exemplified in FIG. 8A, for "I / O node: A", the "data type" is, for example, "DINT", the unit is 32 bits, and the "reference frequency" is "reference frequency". Information that "2000 Hz" and "reference point" are "2000" is registered. Similarly, for "I / O node: B", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000". .. Further, in the "I / O node: C", the "data type" is, for example, "INT", 16 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000".

(Calculation method of sampling speed)
As described above, for each I / O node, the first adjustment unit 130 multiplies the size per unit of data specified by the "data type" by the value of the "sampling frequency" and then "8 bits / byte". , To calculate the sampling rate V _sample . Specifically, the first adjusting unit 130 has sampling rates _VA , _BB , and "I / O node: A", "I / O node: B", and "I / O node: C". For each of the VCs, the following values are calculated as illustrated in ( _B ) of FIG. That is, the first adjusting unit 130 calculates "sampling speed V _A = 8000 byte / s", "sampling speed V _B = 4000 byte / s", and "sampling speed _VC = 2000 byte / s".

(Calculation method of collection time)
Further, the first adjusting unit 130 calculates the collection time T _sample by dividing the value of the “sampling point” by the value of the “sampling frequency” for each I / O node. Specifically, the first adjusting unit 130 collects the “I / O node: A”, “I / O node: B”, and “I / O node: C” collection times _TA , _TB , and For each of the TCs, the following values are calculated as illustrated in ( _B ) of FIG. That is, the first adjusting unit 130 calculates "collection time _TA = 1s", "collection time _TB = 1s", and "collection time _TC = 1s".

(Calculation method of average sampling speed and margin speed)
The first adjusting unit 130 calculates the average sampling rate V _mean from the sampling rate V _sample and the collection time T _sample calculated for each I / O node in the cyclic unit sequence. For example, the first adjusting unit 130 sets the total of all I / O nodes of "a value obtained by multiplying the sampling rate V _sample of each I / O node by the collection time T _sample of each I / O node". The average sampling rate _Vmean is calculated by dividing by the total collection time T _sample for the O node. That is, the first adjusting unit 130 calculates "mean sampling speed V _mean = 4667 bytes / s". Further, since "maximum value V am = 1024 bytes / s", the first adjusting unit 130 _calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = −3643 bytes / s".

When the first adjusting unit 130 confirms that "margin speed V _margin = -3643 byte / s", that is, "margin speed V _margin is less than" 0 "", it is necessary to adjust the collection rule. judge.

As described with reference to FIGS. 7 and 8, the first adjusting unit 130 determines whether or not the collection rule needs to be adjusted by comparing the average sampling rate V _mean with the maximum value V _amm . Then, the first adjustment unit 130, which determines that the collection rule needs to be adjusted, adjusts the collection rule so that the margin speed V _margin becomes "0" or more. Specifically, the first adjustment unit 130 has at least one of the “patrol frequency”, “sampling frequency”, “sampling point”, and “time required to complete the patrol unit sequence” of each I / O node. Adjust one item using the maximum value _Vamm .

(General points to keep in mind when adjusting collection rules)
FIG. 9 is a diagram illustrating a tendency of how the value of the average sampling rate _Vmean changes when the collection rule of a certain I / O node is increased or decreased. Specifically, in FIG. 9, the first adjusting unit 130 adjusts (that is, increases / decreases) the “circulation frequency”, “sampling frequency”, and “sampling point” of each I / O node. It is a figure explaining the general influence on a sampling rate V _mean .

The first adjusting unit 130 makes a round of the "circulation frequency", "sampling frequency", "sampling point", and "circulation unit sequence" of each I / O node according to the purpose of use of the data collected by the collection unit 140. Adjust at least one of the "time required to do". Here, when the collection rule of a certain I / O node is changed, "for the total time required for the first adjusting unit 130 to make a round of the patrol unit sequence (that is, the total collection time T _All ), each The "ratio occupied by the collection time T _sample of the I / O node" changes relatively. Specifically, when at least one of the "patrol frequency", "sampling frequency", and "sampling point" of a certain I / O node is changed, the "total collection time T _All " of each I / O node is changed. The "ratio occupied by the collection time T _sample " changes relatively. Therefore, changing the collection rule of one I / O node may affect the collection rule of other I / O nodes in the cyclic unit sequence, and as a result, the _mean sampling rate Vmean may change significantly. Therefore, FIG. 9 shows a diagram summarizing the changes in the collection rules of each I / O node and their effects on the average sampling rate _Vmean .

FIG. 9A describes the collection rule to be changed and its influence on the average sampling rate V _mean when the sampling rate V _sample of the I / O node that changes the collection rule is larger than the maximum value _Vamm . It is a figure to do. If the "patrol frequency" of the I / O node whose sampling rate V _sample is larger than the maximum value V _am is increased, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value V _am. Sex rises. If the "patrol frequency" of the I / O node whose sampling rate V _sample is larger than the maximum value V _am is reduced, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value V _am. Gender declines.

If the "sampling frequency" of the I / O node where the sampling rate V _sample is larger than the maximum value _Vamm is increased, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value _Vamm . Sex rises. If the "sampling frequency" of the I / O node where the sampling rate V _sample is larger than the maximum value _Vamm is reduced, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value _Vamm . Gender declines.

If the "sampling points" of the I / O node whose sampling rate V _sample is larger than the maximum value V _am is increased, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value V _am. Sex rises. If the "sampling points" of the I / O node whose sampling rate V _sample is larger than the maximum value V _am is reduced, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value V _am. Gender declines.

(B) of FIG. 9 describes the collection rule to be changed and its influence on the average sampling rate V _mean when the sampling rate V _sample of the I / O node that changes the collection rule is smaller than the maximum value _Vamm . It is a figure to do. If the "patrol frequency" of the I / O node whose sampling rate V _sample is smaller than the maximum value V _am is increased, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value V _am. Gender declines. If the "patrol frequency" of the I / O node whose sampling rate V _sample is smaller than the maximum value V _am is reduced, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value V _am. Sex rises.

If the "sampling frequency" of the I / O node where the sampling rate V _sample is smaller than the maximum value _Vamm is increased, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value V _am. Sex rises. If the "sampling frequency" of the I / O node where the sampling rate V _sample is smaller than the maximum value _Vamm is reduced, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value _Vamm . Gender declines.

If the "sampling point" of the I / O node whose sampling rate V _sample is smaller than the maximum value _Vamm is increased, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean can be larger than the maximum value _Vamm . Gender declines. If the "sampling points" of the I / O node whose sampling rate V _sample is smaller than the maximum value V _am is reduced, the average sampling rate V _mean becomes larger and the average sampling rate V _mean can be larger than the maximum value V _am. Sex rises.

FIG. 9C describes the collection rule to be changed and its influence on the average sampling rate V _mean when the sampling rate V _sample of the I / O node that changes the collection rule is equal to the maximum value _Vamm . It is a figure. When the "patrol frequency" of an I / O node whose sampling rate V _sample is equal to the maximum value V _am is increased or decreased, the value of the average sampling rate V _mean is that of other I / O nodes other than that I / O node. Depends on collection rules.

If the "sampling frequency" of the I / O node where the sampling rate V _sample is equal to the maximum value V _am is increased, the average sampling rate V _mean becomes larger and the average sampling rate V _mean may be larger than the maximum value V _am . Rise.

If the "sampling frequency" of the I / O node where the sampling rate V _sample is equal to the maximum value V _am is reduced, the average sampling rate V _mean becomes smaller and the average sampling rate V _mean may be larger than the maximum value V _am . Goes down.

When the "sampling point" of an I / O node whose sampling rate V _sample is equal to the maximum value V _am is increased or decreased, the value of the average sampling rate V _mean is that of other I / O nodes other than that I / O node. Depends on collection rules.

The first adjusting unit 130 is, for example, at least one of the “patrol frequency”, “sampling frequency”, and “sampling point” of each I / O node so that “the margin speed V _margin becomes“ 0 ”or more”. This is adjusted in consideration of the above-mentioned tendency described with reference to FIG.

(An example of the adjustment method when the "sampling frequency" is invariant)
FIG. 10 is a diagram showing an example in which the first adjusting unit 130 adjusts the collection rule so that the average sampling rate _{Vmean is equal to or less than the maximum value Vamm while} keeping the “sampling frequency” of each I / O node unchanged. Is. In FIG. 10, “maximum value _Vamm = 1024byte / s” is set. As illustrated in FIG. 10, the first adjusting unit 130 does not change the “sampling frequency” of each I / O node, for example, the “patrol frequency (more accurately, relative)” of each I / O node. The frequency of patrols) ”is increased or decreased so that the average sampling rate V _mean is set to the maximum value V _amm or less.

FIG. 10A is a diagram showing an example of a collection rule table 183 immediately after the patrol frequency of “I / O node: A” is changed by the second adjusting unit 160. For example, for "I / O node: A", the second adjusting unit 160 that determines that the value stored in the "history" of the collection rule table 183 is equal to or greater than the increase reference value Uth N times in a row The patrol frequency of "I / O node: A" is increased as shown in (A) of FIG. That is, the second adjusting unit 160 patrols "I / O node: A" with respect to "sequential sequence: A, B, C" which is a patrol unit sequence before increasing the patrol frequency of "I / O node: A". The frequency is increased, and the frequency is changed to, for example, "sequence: A, B, A, C" exemplified in (A) of FIG.

In the collection rule table 183 exemplified in FIG. 10A, "sequential columns: A, B, A, C" are stored, and further, "I / O node: A" and "I / O node:" are stored. The following information is stored for each of "B" and "I / O node: C". That is, for "I / O node: A", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "400 Hz", and the "reference point number" is "1000". Information is registered. Similarly, for "I / O node: B", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "400 Hz", and the "reference point number" is "1000". .. Further, in the "I / O node: C", the "data type" is, for example, "INT", 16 bits per unit, the "reference frequency" is "200 Hz", and the "reference point number" is "1000".

(Calculation method of sampling speed)
Using the methods described so far, the first adjusting unit 130 has a sampling rate VA of "I / O node: _A ", "I / O node: B", and "I / O node: C". , V _B , and _VC , respectively, the following values are calculated as illustrated in FIG. 10 (A). That is, the first adjusting unit 130 calculates "sampling speed V _A = 1600 bytes / s", "sampling speed V _B = 1600 bytes / s", and "sampling speed _VC = 400 bytes / s".

(Calculation method of collection time)
Further, using the method described so far, the first adjusting unit 130 collects "I / O node: A", "I / O node: B", and "I / O node: C". For each of TA, _TB , and _TC , the following values are calculated as illustrated in ( _A ) of FIG. That is, the first adjusting unit 130 calculates "collection time _TA = 2.5s", "collection time _TB = 2.5s", and "collection time _TC = 5s".

(Calculation method of average sampling speed and margin speed)
The first adjusting unit 130 calculates the average sampling rate V _mean from the sampling rate V _sample and the collection time T _sample calculated for each I / O node in the cyclic unit sequence. For example, the first adjusting unit 130 sets the total of all I / O nodes of "a value obtained by multiplying the sampling rate V _sample of each I / O node by the collection time T _sample of each I / O node". The average sampling rate _Vmean is calculated by dividing by the total collection time T _sample for the O node. That is, the first adjusting unit 130 calculates "mean sampling speed V _mean = 1120 bytes / s". Further, since "maximum value V am = 1024 bytes / s", the first adjusting unit 130 _calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = -96 bytes / s".

When the first adjusting unit 130 confirms that "margin speed V _margin = -96 byte / s", that is, "margin speed V _margin is less than" 0 "", it is necessary to adjust the collection rule. judge.

(Example of adjusting patrol frequency)
The first adjusting unit 130 does not change the "sampling frequency" of each I / O node, but increases or decreases the "patrol frequency" of each I / O node, for example, as illustrated in FIG. 10B. , The average sampling rate V _mean is set to the maximum value V _amm or less.

Here, as described with reference to FIG. 9, when the “patrol frequency” of the I / O node of the sampling rate V _sample larger than the maximum value _Vamm is reduced, the average sampling rate V _mean is generally reduced. ((A) in FIG. 9). Further, when the "patrol frequency" of the I / O node of the sampling rate V _sample smaller than the maximum value _Vamm is increased, the average sampling rate V _mean generally becomes smaller ((B) in FIG. 9).

Since "maximum value V _amm = 1024 bytes / s", "sampling speed V _B = 1600 bytes / s" is larger than the maximum value V _amm , and "sampling speed VC = 400 bytes / s" is _{larger than the maximum value V amm .} small.

Therefore, the first adjusting unit 130 describes the "circulation frequency (more accurately," relative patrol frequency ") of the" I / O node: B "for the" sequence: A, B, A, C ". Perform at least one of a decrease and an increase in the "patrol frequency" of "I / O node: C". For example, when the importance of "I / O node: B" is lower than the importance of "I / O node: A" and "I / O node: C", the first adjusting unit 130 is shown in FIG. The "order: A, B, A, C" in (A) is changed to the "order: A, B, C, A, A, C" in (B) of FIG.

In the "sequential sequence: A, B, A, C", the patrol frequency of each of the "I / O nodes: A, B, and C" is "2, 1, 1 (relatively 2/4, 1/4, 1/4) ". On the other hand, in the "order: A, B, C, A, A, C", the patrol frequency of each of the "I / O nodes: A, B, and C" is "3, 1, 2 (relative). 3/6, 1/6, 2/6) ”. That is, the first adjusting unit 130 sets the "patrol frequency (more accurately," relative patrol frequency ") of the" I / O node: B "for the" sequence: A, B, A, C ". Decrease, increase the "patrol frequency" of "I / O node: C", and change to "order: A, B, C, A, A, C".

As illustrated in (B) of FIG. 10, the average sampling rate V _mean calculated by the first adjusting unit 130 for “sequential sequence: A, B, C, A, A, C” is “average sampling rate V _mean = 1000 bytes”. / S ". Since "maximum value V _amm = 1024 bytes / s", the first adjusting unit 130 calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = 24 bytes / s". The first adjusting unit 130, which has determined that the margin speed V _margin is 0 or more, adopts this "sequential sequence: A, B, C, A, A, C" as the patrol unit sequential sequence to be followed by the collecting unit 140.

As described with reference to FIG. 10, the first adjusting unit 130 does not change the “sampling frequency” of each I / O node in the patrol unit sequence, but the “patrol frequency (relative) of each I / O node. The patrol frequency) ”is increased or decreased so that the average sampling rate V _mean is set to the maximum value V _amm or less. For example, the first adjusting unit 130 reduces the "patrol frequency" of "I / O node: B" from "1/4 to 1/6" and reduces the "patrol frequency" of "I / O node: C". Increase "from 1/4 to 2/6" so that the mean sampling rate V _mean is less than or equal to the maximum value V _am .

The average sampling speed V for the "sequential sequence: A, B, A, C" in which the patrol frequency from the "sequential sequence: A, B, C" to the "I / O node: A" was increased by the second adjusting unit 160. The adjustment method for setting the _mean to the maximum value _Vamm or less is not limited to the above. For example, the first adjusting unit 130 returns the “sequential sequence: A, B, A, C” exemplified in FIG. 10 (B) to the “sequential sequence: A, B, C”, whereby the average sampling rate _Vmean . May be set to a maximum value of V _am or less.

(An example of the adjustment method when the "patrol frequency" and "sampling score" are unchanged)
In FIG. 11, the first adjusting unit 130 adjusts the collection rule so that the average sampling rate V _mean is equal to or less than the maximum value _Vamm while keeping the “patrol frequency” and “sampling point” of each I / O node unchanged. It is a figure which shows the example. In FIG. 11, “maximum value _Vamm = 1024byte / s” is set. As illustrated in FIG. 11, the first adjusting unit 130 does not change the “patrol frequency” and the “sampling point” of each I / O node in the patrol unit sequence, for example, “sampling” of each I / O node. The "frequency" is increased or decreased so that the average sampling rate V _mean is set to the maximum value V _am or less.

FIG. 11A is an example of the collection rule table 183 before adjustment by the first adjustment unit 130, and is an example of “I / O node: A” and “I / O node” of “order: A, B, C”. : B ”and“ I / O node: C ”are stored in the following information. That is, for "I / O node: A", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "2000 Hz", and the "reference point number" is "2000". Information is registered. Similarly, for "I / O node: B", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000". .. Further, in the "I / O node: C", the "data type" is, for example, "INT", 16 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000".

(Calculation method of sampling speed and collection time)
Using the method described so far, the first adjusting unit 130 determines the sampling speeds _VA , _BB , VC and the collection time TA for "I / O nodes: _A , B, and _C ". Calculate _TB and _TC . That is, the first adjusting unit 130 calculates "sampling speed V _A = 8000 byte / s", "sampling speed V _B = 4000 byte / s", and "sampling speed _VC = 2000 byte / s". Further, the first adjusting unit 130 calculates "collection time _TA = 1s", "collection time _TB = 1s", and "collection time _TC = 1s".

(Calculation method of average sampling speed and margin speed)
The first adjusting unit 130 calculates "mean sampling rate V _mean = 4667 bytes / s" from the sampling rate V _sample and the collection time T _sample calculated for each I / O node in the cyclic unit sequence. Further, since "maximum value V am = 1024 bytes / s", the first adjusting unit 130 _calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = −3643 bytes / s".

When the first adjusting unit 130 confirms that "margin speed V _margin = -3643 byte / s", that is, "margin speed V _margin is less than" 0 "", it is necessary to adjust the collection rule. judge.

(Sampling frequency adjustment example)
The first adjusting unit 130 does not change the “patrol frequency” and the “sampling point” of each I / O node in the patrol unit sequence, for example, as illustrated in FIG. 11B, each I / O node. The "sampling frequency" of the above is increased or decreased so that the average sampling speed _Vmaan is set to the maximum value _Vamm or less.

First, the first adjustment unit 130 calculates a "reduction rate R" which is a value obtained by dividing the "maximum value V _amm = 1024 bytes / s" by the "mean sampling rate V _mean = 4667 bytes / s" before adjustment. That is,

Is.

Next, the first adjustment unit 130 multiplies the sampling frequency ( _{FA_uncorrected} , _{FB_uncorrected} , _{FC_uncorrected} ) before adjustment of each I / O node by the reduction rate R, and each I / O node. The adjusted sampling frequency ( _{after FA_correction} , _{after FB_correction} , after _{FC_correction} ) is calculated. That is,

Is calculated.

Then, for each I / O node, the first adjustment unit 130 multiplies the size per unit of data specified by the "data type" by the value of the "adjusted sampling frequency", and then "8 bits /". Divide by "byte" to calculate the adjusted sampling rate V _sample . Specifically, the first adjusting unit 130 has adjusted sampling speeds _VA , V of "I / O node: A", "I / O node: B", and "I / O node: C". For each of _B and _VC , the following values are calculated as illustrated in (B) of FIG. That is, the first adjusting unit 130 has "adjusted sampling speed _VA = 1756 byte / s", "adjusted sampling speed V _B = 876 byte / s", and "adjusted sampling rate _VC = 438 byte / s". Is calculated.

Further, the first adjustment unit 130 calculates the adjusted collection time T _sample by dividing the value of the “sampling point” by the value of the “adjusted sampling frequency” for each I / O node. Specifically, the first adjusting unit 130 has the adjusted collection times TA, T of "I / O node: _A ", "I / O node: B", and "I / O node: C". For each of _B and _TC , the following values are calculated as illustrated in (B) of FIG. That is, the first adjusting unit 130 has "adjusted collection time _TA = 4.6s", "adjusted collection time _TB = 4.6s", and "adjusted collection time _TC = 4.6s". Is calculated.

As described above, the first adjusting unit 130 has adjusted sampling rates _VA , _BB , _VC calculated for each I / O node in the cyclic unit sequence, and adjusted collection times _TA , _TB , T. From _C , the adjusted "mean sampling rate V _mean (also referred to as" V _{mean_corrected} ")" is calculated. Specifically, the average sampling rate V _mean is “average sampling rate V _mean = 1024 bytes / s” as illustrated in FIG. 11 (B). Since "maximum value V _amm = 1024 bytes / s", the first adjusting unit 130 calculates "margin speed V _margin = maximum value V _amm -mean sampling speed V _mean = 0 bytes / s". The first adjusting unit 130, which determines that the margin speed V _margin is 0 or more, samples the adjusted sampling frequency ( _{after FA_correction} , _{after FB_correction} , after _{FC_correction} ) to be followed by the collection unit 140. Adopt as a frequency.

(An example of adjustment method when inserting "waiting time")
In FIG. 12, the first adjusting unit 130 inserts a waiting time during the sampling process so that the average sampling speed V _mean is equal to or less than the maximum value _Vamm . It is a figure which shows the example which adjusts. In FIG. 12, “maximum value _Vamm = 1024byte / s” is set. As illustrated in FIG. 12, the first adjusting unit 130 does not change the "circulation frequency", "sampling frequency", and "sampling point" of each I / O node in the circulation unit sequence, and performs the "circulation unit sequence". Increase or decrease the "time required to make a round" so that the average sampling rate V _mean is set to the maximum value V _amm or less.

FIG. 12A is an example of the collection rule table 183 before adjustment by the first adjustment unit 130, and is an example of “I / O node: A” and “I / O node” of “order: A, B, C”. : B ”and“ I / O node: C ”are stored in the following information. That is, for "I / O node: A", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "2000 Hz", and the "reference point number" is "2000". Information is registered. Similarly, for "I / O node: B", the "data type" is, for example, "DINT", 32 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000". .. Further, in the "I / O node: C", the "data type" is, for example, "INT", 16 bits per unit, the "reference frequency" is "1000 Hz", and the "reference point number" is "1000".

(Calculation method of sampling speed and collection time)
Using the method described so far, the first adjusting unit 130 determines the sampling speeds _VA , _BB , VC and the collection time TA for "I / O nodes: _A , B, and _C ". Calculate _TB and _TC . That is, the first adjusting unit 130 calculates "sampling speed V _A = 8000 byte / s", "sampling speed V _B = 4000 byte / s", and "sampling speed _VC = 2000 byte / s". Further, the first adjusting unit 130 calculates "collection time _TA = 1s", "collection time _TB = 1s", and "collection time _TC = 1s".

(Calculation method of average sampling speed and margin speed)
The first adjusting unit 130 calculates "mean sampling rate V _mean = 4667 bytes / s" from the sampling rate V _sample and the collection time T _sample calculated for each I / O node in the cyclic unit sequence. Further, since "maximum value V am = 1024 bytes / s", the first adjusting unit 130 _calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = −3643 bytes / s".

When the first adjusting unit 130 confirms that "margin speed V _margin = -3643 byte / s", that is, "margin speed V _margin is less than" 0 "", it is necessary to adjust the collection rule. judge.

(Example of inserting "waiting time")
The first adjusting unit 130 inserts, for example, a “waiting time T _D ” as illustrated in FIG. 12B without changing the “patrol frequency”, “sampling frequency”, and “sampling point”. , The average sampling rate V _mean is set to the maximum value V _amm or less.

Average sampling speed after correction V _{mean_ After correction,} the maximum value is less than V _amm , that is,

Will be. The first adjusting unit 130 solves this, that is,

Will be. The first adjusting unit 130 inserts the "waiting time T _D " into the "order: A, B, C", and specifically, as illustrated in FIG. 12 (B), the "waiting time T _D ". Is stored in the collection rule table 183. That is, in FIG. 12B, only “ID: D” and “collection time: 10.7s” are stored in the collection rule table 183 exemplified in FIG. 12A, and other items are included. A collection rule table 183 is shown with the addition of rows that do not contain data.

The "total collection time T _All ", which is the total of the collection time T _samples of each I / O node in the "order: A, B, C", is "total collection time T _All = 1 + 1 + 1 = 3s". "Total collection time T _All " of "Sequential: A, B, C, D" with "Waiting time T _D " inserted in "Sequential: A, B, C" is "Total collection time T _All = 1 + 1 + 1 + 10.7 = 13.7s ". Since "I / O node: D" is a node corresponding to the waiting time, the "sampling point" of "I / O node: D" is "0", that is, "I / O node: D". The amount of data collected for "" is "0".

The first adjusting unit 130 does not change the "data amount of data to be collected until one round of the patrol unit sequence", but "inserts a waiting time and sets the total collection time T _All required to complete the cycle of the patrol unit sequence". By "increasing", the average sampling rate V _mean is decreased.

As illustrated in FIG. 12 (B), the average sampling rate V _mean calculated by the first adjusting unit 130 for the “sequential sequence: A, B, C, D” is “average sampling rate V _mean = 1022byte / s”. Become. Since "maximum value V _amm = 1024 bytes / s", the first adjusting unit 130 calculates "margin speed V _margin = maximum value V _amm -mean sampling rate V _mean = 2 bytes / s". The first adjusting unit 130, which is determined to have a margin speed V _margin of 0 or more, is stored in the collection rule table 183 shown in FIG. 12 (B) including this “sequential sequence: A, B, C, D”. The collection rule is adopted as the patrol unit sequence to be followed by the collection unit 140.

(About display processing)
FIG. 13 is a diagram showing an example of information to be displayed on the display screen of an external display device such as a tool by the display control unit 170. The display control unit 170 displays information related to the sampling process being executed on the display screen (for example, the display screen of an external display device such as a tool), and the maximum set by the user, for example, as illustrated in FIG. Display the value V _amm . In the example shown in FIG. 13, the display control unit 170 further indicates the average sampling rate V _mean indicating the magnitude of the processing load related to the sampling process during execution, and the difference between the maximum value _Vamm and the average sampling rate V _mean . The _margin speed V marin, which is, is displayed.

Further, the display control unit 170 may, for example, "name each of the plurality of I / O nodes included in the patrol unit sequence", "the appearance order of each I / O node in the patrol unit sequence", and "currently, Display the "I / O node for which data is to be collected". Further, the display control unit 170 displays, for example, the “sampling frequency”, the “sampling point”, and the “importance to the latest data” in the collection rule being applied for each I / O node.

§4. Modification Example FIG. 14 is a diagram showing an example of the data structure of the collection rule table 183, which is different from that illustrated in FIG. 4, for the collection rule table 183 stored in the storage unit 180. The collection rule table 183 exemplified in FIG. 14 has an item of "collection flag variable" in addition to the items provided in the collection rule table 183 illustrated in FIG.

The collection unit 140 collects the data of the I / O node whose "collection flag variable" of the collection rule table 183 is "TRUE" among the control data stored in the control data table 181 and collects the "collection flag variable". Does not collect data for the "FALSE" I / O node. That is, among the control data acquired by the acquisition unit 110 from the slave device for each control cycle, the collection unit 140 collects only the I / O nodes whose “collection flag variable” in the collection rule table 183 is “TRUE”. set to target.

The first adjustment unit 130 collects only the data of the I / O node that needs to be sampled by targeting only the I / O node whose "collection flag variable" of the collection rule table 183 is "TRUE". can do.

When the collection rule table 183 has an item of "collection flag variable", the first adjusting unit 130 sets the "sampling score" of the I / O node whose "collection flag variable" is "FALSE" to "0" and averages it. Calculate the sampling rate V _mean .

[Example of implementation by software]
The control block of the PLC 10 (specifically, the acquisition unit 110, the reception unit 120, the first adjustment unit 130, the collection unit 140, the evaluation unit 150, the second adjustment unit 160, and the display control unit 170) is an integrated circuit (specifically, the display control unit 170). It may be realized by a logic circuit (hardware) formed in an IC chip) or the like, or may be realized by software using a CPU (Central Processing Unit).

In the latter case, the PLC 10 is a CPU that executes instructions of a program that is software that realizes each function, a ROM (Read Only Memory) or a storage device in which the above program and various data are readablely recorded by a computer (or CPU). (These are referred to as "recording media"), RAM (Random Access Memory) for expanding the above program, and the like are provided. Then, the object of the present invention is achieved by the computer (or CPU) reading the program from the recording medium and executing the program. As the recording medium, a "non-temporary tangible medium", for example, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Control system (master-slave control system)
10 PLC (master device)
20 Database (external device)
30 Servo driver (slave device)
120 Reception unit 130 1st adjustment unit 140 Collection unit 160 2nd adjustment unit 170 Display control unit R Reduction rate (uniform rate)
S110 Reception step S140 First adjustment step S150 Collection step T _All Total collection time (time required by the collection unit to complete the sequence)
V _amm maximum value (maximum value specified by the user)
V _mean average sampling rate (data amount of data collected per unit time)
V _margin margin speed (maximum value _Vamm -mean sampling speed V _mean )

Claims (10)

A master device in a master-slave control system
A collection unit that repeatedly collects each of a plurality of data to be transmitted to the external device from the control data periodically acquired from the slave device according to a predetermined collection rule.
A reception unit that accepts the maximum value specified by the user for the amount of data collected per unit time by the collection unit.
The first adjustment that adjusts the predetermined collection rule so that the amount of data collected per unit time by the collection unit according to the predetermined collection rule is equal to or less than the maximum value accepted by the reception unit. Department and
Master device with. The predetermined collection rule includes a sequence indicating the collection order of each of the plurality of data collected by the collection unit.
The collecting unit repeatedly collects each of the plurality of data according to the order.
The amount of data collected per unit time by the collecting unit in accordance with the predetermined collection rule is the amount of data collected by the collecting unit by the time the order is cycled. The master device according to claim 1, which is a value divided by the time required by the collecting unit. The first adjusting unit, as the predetermined collection rule, (1) the number of appearances of each of the plurality of data in the sequence, and (2) each appearance of each of the plurality of data in the sequence once. The number of data points collected in, (3) the collection frequency, which is the number of data points collected per unit time for each appearance of each of the plurality of data in the sequence, and (4) one round of the sequence. The master device according to claim 2, wherein at least one of the times required by the collecting unit is adjusted. When the evaluation value given to each of the plurality of data collected by the collecting unit meets a predetermined standard, the data to which the evaluation value satisfying the predetermined standard is given is (1) in the above-mentioned order sequence. At least the number of appearances, (2) the number of data points collected for each appearance in the sequence, and (3) the number of data points collected per unit time for each appearance in the sequence. Further equipped with a second adjustment unit to adjust one,
The first adjusting unit obtains the predetermined number of appearances adjusted by the second adjusting unit, the number of data points collected for each appearance in the order, and the predetermined collection rule including the collection frequency. The master apparatus according to claim 2 or 3, further adjusted using the maximum value. The first adjusting unit includes (1) the number of data points collected for each appearance of each of the plurality of data in the sequence, and (2) 1 of each of the plurality of data in the sequence. The master device according to any one of claims 2 to 4, wherein at least one of the collection frequencies, which is the number of data points collected per unit time for each appearance, is reduced at a uniform rate. (1) the maximum value, (2) the amount of data collected per unit time by the collecting unit according to the predetermined collection rule adjusted by the first adjusting unit, and (3) the difference between the two. The master device according to any one of claims 1 to 5, further comprising a display control unit to be displayed to the user. The plurality of data collected by the collecting unit is any one of claims 1 to 6, which is data selected as a collection target by the user among the control data periodically acquired from the slave device. The master device described in. It is a control method of the master device in the master-slave control system.
A collection step of repeatedly collecting each of a plurality of data to be transmitted to the external device from the control data periodically acquired from the slave device according to a predetermined collection rule.
A reception step that accepts the maximum value specified by the user for the amount of data collected per unit time in the collection step, and a reception step.
The predetermined collection rule is adjusted so that the amount of data collected per unit time in the collection step according to the predetermined collection rule is equal to or less than the maximum value received in the reception step. 1 adjustment step and
Control methods including. An information processing program for operating a computer as the master device according to any one of claims 1 to 7, and an information processing program for operating the computer as each part. A computer-readable recording medium on which the information processing program according to claim 9 is recorded.

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