JP2005259077A - Slave and monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide slaves capable of notifying a state such as abnormality of equipment to be controlled (to be monitored) while suppressing the load of a programmable controller (PLC) etc. <P>SOLUTION: A master unit 2 constituting the PLC1 and a plurality of slaves 10 are connected with a field network 3. Four temperature sensors 5 are connected with the slaves, the temperature sensors measure temperatures of different control targets 6, respectively and transmits them to the slaves. A plurality of control targets are the same kind and any one shows the same heating state when they are in normal states. The slaves arithmetically operate fetched temperature data inside, calculate difference between temperatures (analog data) detected by the plurality of connected temperature sensors, compare the difference with a threshold and notifies the PLC of only its result. Namely, since each temperature is approximately equal when the control targets are normal, the difference becomes equal to or less than the threshold, however, when a certain control target breaks down, only temperature of the control target rises and the difference exceeds the threshold. Thus, the abnormality is detected. The slaves perform to abnormality decision and notifies its result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a slave and a monitoring system.

  As is well known, in factory automation (hereinafter referred to as “FA”), I / O devices and other devices / devices are directly connected to a programmable controller (hereinafter referred to as “PLC”) or via a network. Connected. The PLC acquires information from an input device such as a switch or a sensor that is a kind of the I / O device as input data, and executes arithmetic processing using the acquired input data in accordance with a user program incorporated in advance. The entire FA system is controlled by determining the control content for an output device, which is a type of I / O device, and outputting control data corresponding to the control content to an output device such as a valve, actuator, or motor. It is like that.

  More specifically, the control in the CPU unit of the PLC takes in the signal input from the input device connected to the input unit into the I / O memory of the CPU unit (IN refresh), and is built in a ladder language registered in advance. Performs logical operation based on the user program (operation execution), writes the operation execution result to the I / O memory and sends it to the output unit (OUT refresh), and the output unit performs control to drive and stop the output device. Thereafter, so-called peripheral processing is performed such that communication processing is performed via the communication network. In this way, the PLC cyclically repeats IN refresh, operation execution, OUT refresh, and peripheral processing.

  By the way, the input device and the output device may be directly connected to an input / output unit constituting the PLC or may be connected via a network. As a form of connection via the network, for example, master-slave communication can be performed. In this case, a master unit (master) and a slave constituting the PLC are connected to a field network, and communication between the master and the slave is enabled via the field network. By connecting an input device or an output device to this slave, for example, an input signal detected by the input device is transmitted to the master via the slave and field network, and from the master to the CPU unit via the PLC bus. The

  On the PLC side, the user program is executed based on the acquired input information, and the execution result is transmitted as a control command signal via the master unit to the slave via the network, and an output device (relay or Control commands are sent to valves, actuators, etc.

  Furthermore, there are various types of input devices, such as those that output ON / OFF data as input information, such as limit switches, and those that output analog data as input information, such as temperature sensors.

  In addition, transmission / reception of I / O information such as input signals and output signals of devices connected to the slave is performed at a communication timing set in advance between the slave and the master unit, and is asynchronous with the cyclic processing of the PLC. And it is operating at a different timing. The CPU unit of the PLC and the master unit are connected via a bus, and the cyclic processing in the CPU unit can be used to transfer data to and from the master unit using IN refresh, OUT refresh (I / O refresh), or peripheral service processing. Sending and receiving are done. Thereby, the CPU unit of the PLC can connect the input or output device arranged remotely to the slave and transmit / receive data via the network.

  By the way, in recent FA network systems, in addition to managing and monitoring the current control contents, there is an increasing demand for appropriately monitoring and monitoring non-control information such as information about the state of the system. . For example, if it is known that the temperature rises when the control target fails, a temperature sensor is installed in the control target, and analog data (temperature of the control target) output from the temperature sensor is constantly monitored and set in advance. When the measured temperature is exceeded, it can be determined that an abnormality has occurred.

  In order to realize such processing, usually the analog data collected from the slave is processed by the PLC (CPU unit) on the upper side, and the deterioration status of the device and the maintenance time are grasped from the processing result. To be done.

  In order to execute such processing, an analysis program for executing the processing is created and added to the user program. However, if processing is performed on the PLC side, the load of PLC program execution processing increases, which is not preferable. The user program is a language suitable for control, and is not good at setting parameters such as temperature adjustment.

  Further, there is a problem that the communication load with the slave increases. Since it is necessary to always obtain the latest information from the slave, it is necessary to communicate basic data related to maintenance information in addition to control information as I / O data in the communication process between the master and slave of the PLC. Occurs. This increases the amount of communication information, increases the communication processing time, and increases the communication cycle between the master and the slave.

  Furthermore, since the control program is the main and important program in the upper side in FA control, there is a high risk of mixing programs such as comparative analysis and information management. In particular, if a data analysis program is added later to a control program that is already operating / operating, the control program may be adversely affected, making it difficult to actually add the program.

As a technique for suppressing unnecessary transmission between the master and the slave, there is an invention disclosed in Patent Document 1. In the disclosed invention, a difference setting value for a change in analog data necessary for a slave is set in advance. When the difference between the current value and the transmission value transmitted last time is equal to or greater than the difference setting value or exceeds the difference setting value and a preset transmission standby time has elapsed since the previous transmission, the current value is sent to the upper level through the network. It is a thing.
JP 11-39025 A

  However, the above-described conventional system has the following problems. In the technique disclosed in Patent Document 1, analog data is not output unless a preset difference set value is exceeded. Accordingly, the number of analog data transmissions communicated through the field network is reduced. Further, the final determination is made by a higher-level device such as a PLC, and a program such as comparative analysis / information management is still required in the PLC.

  For example, in the case of temperature, an appropriate threshold value for determining an abnormality may vary depending on the ambient temperature and other external factors. If it does so, if it manages by an absolute value, it will become impossible to judge correctly. Furthermore, even if we know that “temperature rises when an abnormality occurs in the control target”, it will become abnormal if it rises more specifically or more than an absolute value (difference setting value). There is something I don't know about. Therefore, the invention disclosed in Patent Document 1 also has a problem that it cannot cope with such a situation. Furthermore, in the technique disclosed in Patent Document 1, since the comparison with the previous measurement data is simply performed, events that can detect an abnormality or the like are limited.

  An object of the present invention is to provide a slave and a monitoring system that can notify a state of abnormality or the like of a device to be controlled (monitoring target) while suppressing a load such as a PLC.

  The slave according to the present invention is a slave that is connected to a plurality of analog devices that output analog data as input data and communicates with the controller via a network, and specifies two of the plurality of analog devices. , Using analog data of the designated analog device, a calculation means for performing a predetermined calculation process, and a comparison for comparing the calculation result obtained by the calculation means with a threshold value to determine whether or not the notification condition is satisfied And means for outputting the determination result by the comparison means to the network.

  The controller corresponds to the PLC 1 in the embodiment. The calculation means corresponds to the calculation unit 13a in the embodiment, and the comparison means corresponds to the threshold comparison processing unit 13d in the embodiment. The means for outputting to the network is realized by the status notification processing unit 13f, the status management unit 15, and the like. The timing for outputting to the network may be voluntary or may be based on a request from the outside. The analog data output from the analog device may be used for FA control or may be collected for monitoring / maintenance.

  According to the present invention, arithmetic processing is performed on the slave side based on the acquired analog data, and it is determined whether the notification condition is satisfied. Therefore, a higher-level device such as a PLC sees the determination result. Can be monitored only by Therefore, the higher-level apparatus does not need to add a program for such monitoring.

  Furthermore, since the arithmetic means performs arithmetic processing based on analog data acquired from two designated analog devices, for example, the two analog devices can be compared. In other words, the arithmetic processing can obtain a difference between the plurality of analog data. For example, when analog data is sent from analog devices installed on the same type of control target (monitoring target), if the control target (monitoring target) is normal, each analog data takes the same value. . Therefore, if a difference is taken and the difference exceeds a threshold value, it can be determined that one of them is in an abnormal state or is likely to be abnormal. In other words, by comparing data of different analog devices connected in the slave, the relative comparison result of the analog data can be easily recognized. As a result, when similar measurement is performed with multiple channels, it can be used as a criterion for determining failure or deterioration, which contributes to improvement in maintainability and maintainability. Furthermore, the necessity of calibration and offset adjustment can be easily recognized by comparing data between channels in the slave. Of course, in the present invention, various arithmetic processes are possible without being limited to the difference.

  Further, the calculation means is based on a calculation result obtained by performing calculation processing between the analog data of two designated analog devices, and analog data of any one of the plurality of analog devices. A predetermined calculation can be performed. As another configuration, the calculation means may designate a plurality of combinations of the two analog devices and perform a predetermined calculation process for each designated set. Furthermore, the calculation means designates a plurality of combinations of the two analog devices and performs a predetermined calculation process for each designated set, and the comparison means sets the calculation result for each set as a threshold value. It is also possible to provide a function for obtaining an individual status as to whether or not the threshold value is exceeded as compared with the above and obtaining a representative status based on each individual status. As described above, by appropriately setting the arithmetic processing, more complicated determination can be performed on the slave side.

  The determination result can be output when the notification condition is satisfied. In other words, it may be output regardless of whether or not the notification condition is satisfied, but by outputting only when the notification condition is satisfied, it is possible to suppress frequent transmission of the determination result on the network. By notifying at any time, the amount of communication is suppressed, and data transmission and reception for the original FA control can be efficiently performed.

  In addition, an analog device that outputs analog data as input data is connected, and is a slave that communicates with the controller via a network, using analog data acquired from the analog device and data stored in the slave in advance. Computation means for performing the set computation processing, comparison means for comparing the computation result obtained by the computation means with a threshold value to determine whether the notification condition is satisfied, and outputting the judgment result by the comparison means to the network It is also possible to configure with a means to do.

  As described above, the calculation in the calculation means can be performed using analog data acquired from the analog device and other data in the slave. The internal data includes, for example, designated values set in advance by the user, calculation results obtained by calculation processing based on analog data, and various other data. In other words, in the present invention, arithmetic processing can be performed based only on a plurality of analog data obtained from an analog device, or arithmetic processing can be performed in consideration of analog data and other data.

  In the monitoring system according to the present invention, in the system in which each of the slaves and the controller described above are connected via a network, the controller satisfies the notification condition by acquiring the determination result of the slave. Recognize that.

  In the present invention, since the slave that has acquired the analog data performs an arithmetic process to determine the state and the like, the state of the control target (monitoring target) device abnormality and the like while suppressing the load on the higher-level device such as the PLC Can be notified.

  FIG. 1 shows an example of a network system to which the present invention is applied. In this example, the master unit 2 constituting the PLC 1 and a plurality of slaves 10 are connected to the field network 3, and the master unit 2 and the slaves 10 can communicate with each other via the field network 3. The slave 10 includes an IN slave that captures an input signal, an OUT slave that outputs an output signal, a Mix slave that inputs and outputs. Then, in relation to the present invention, it is a slave that handles analog data, and four temperature sensors 5 are connected. These four temperature sensors 5 each measure the temperature of another control object 6 and send it to the slave 10. The plurality of control objects 6 are of the same type, and are all in the same heat generation state in a normal state.

  The slave 10 in the present embodiment processes analog data and can also be referred to as an analog slave. Then, the calculated temperature data is calculated internally, a difference between temperatures (analog data) detected by a plurality of connected temperature sensors 5 is obtained, compared with a threshold value, and only the result is notified to the PLC. Like to do. That is, the normal slave sends the acquired analog data to the PLC 1 (master unit 2), but in this example, the analog data is used for arithmetic processing, and information based on the arithmetic result is sent.

  Furthermore, a host management computer 7 is connected to the PLC 1. The upper management computer 7 grasps the deterioration state and the maintenance time only from the notification result from the slave 10.

  FIG. 2 is a software configuration diagram of the slave 10. As is apparent from this figure, the slave 10 includes a data acquisition driver 11, a data conversion processing unit 12, an arithmetic processing unit 13, a timer processing unit 14, a status management unit 15, a communication driver 16, and communication data. A processing unit 17, a hardware processing unit 18, and a main processing unit 19 are provided.

  The data acquisition driver 11 has a function of acquiring analog data sent from connected hardware, that is, the temperature sensor 5, and passing it to the data conversion processing unit 12. The data acquisition driver 11 is activated based on an instruction from the internal timer processing unit 14.

  The data conversion processing unit 12 has a function of converting (converting) internal analog data into data (physical quantity) for showing to the user. The data obtained by the conversion is transferred to the communication data processing unit 17. That is, the analog data acquired via the data acquisition driver 11 is a numerical value such as the amount of electricity output from the temperature sensor 5, for example, and the temperature value (“X” of X ° C.) is not sent. Absent. Therefore, the amount of electricity (for example, “10”) sent from the sensor is converted to a specific temperature (for example, “30 ° C.”). Such conversion processing may store and hold a conversion table in which analog data and data (physical quantity) to be shown to the user are associated with each other, refer to the conversion table, or prepare a conversion formula and calculate it each time. You may ask.

  The arithmetic processing unit 13 executes various types of arithmetic processing based on the data obtained by the data conversion processing unit 12, and performs determination and other processing. It has operation data inside and passes the processing result to the communication data processing unit 17 and outputs it to the outside (PLC etc. in the present embodiment), or conversely via the communication data processing unit 17 (external) If a notification such as a calculation condition change from is received, change according to the notification. Further, a result obtained by performing determination processing such as an alarm output when the threshold value is exceeded is passed to the status management unit 15. Specific processing functions of the arithmetic processing unit 13 will be described later.

  The timer processing unit 14 includes an internal timer, and gives a start command to the data acquisition driver 11, the arithmetic processing unit 13, and the communication data processing unit 17 based on the internal timer. That is, timer management is performed for each of these processing units and the like, and each processing is performed periodically.

  The status management unit 15 manages the state of the entire software. As an example, abnormal information and other statuses managed by the arithmetic processing unit 13 and the main processing unit 1 are received and stored (managed). The managed status is transferred as status data to the communication data processing unit 17 so that it can be transmitted to the host PLC 1 or the like.

  The communication driver 16 is a processing unit that communicates with a host device (PLC 1 or the like) on the field network 3. Data to be transmitted uses data generated by the communication data processing unit 17. Information received via the field network 3 is given to the arithmetic processing unit 13.

  The communication data processing unit 17 manages a protocol that controls the field network 3 and communication data. Data managed here is processed as communication data. Data that goes out is transmitted upward. Data input from the outside is output by the hardware processing unit 18. The communication data has IO communication for constantly exchanging with message communication that accepts an event or the like each time.

  The hardware processing unit 18 actually interfaces with the hardware, and processes the output from the higher-level communication and reads the input from the outside (microcomputer SW information, non-volatile memory read / write, etc.). Or use it when

  Further, the main processing unit 19 performs main processing for the entire software. It has the function of managing the entire software state, notifying the status if there is an abnormal state as software, or stopping itself.

  FIG. 3 is a more detailed functional block diagram of the arithmetic processing unit 13. The calculation processing unit 13 includes a calculation unit 13a, a calculation method management unit 13b, a calculation combination management unit 13c, a threshold comparison processing unit 13d, a threshold change processing unit 13e, and a status notification processing unit 13f.

  The calculation method management unit 13b manages conditions for what kind of calculation is performed. Specific calculation methods include, for example, various arithmetic operations, counts (increment, decrement, average, etc.), and the like are stored in the nonvolatile memory 10a. That is, the calculation method management unit 13b calls the calculation method stored in the nonvolatile memory 10a at other timings when the power is turned on and holds it while the apparatus is in operation. Then, at a predetermined timing, the stored calculation method is transferred to the calculation unit 13a. Further, for example, when a change in calculation method is received from the host computer or PLC via the communication data processing unit 17, the stored calculation method is updated to the received content and is also received by the nonvolatile memory 10a. Store the calculation method and update processing. As a result, the latest calculation method can be maintained whenever the power is turned off.

  The calculation combination management unit 13c manages conditions regarding which data is used for calculation. That is, in this embodiment, for example, since four temperature sensors 5 (1ch, 2ch, 3ch, 4ch) are connected to the slave 10, which channel (one or a plurality: usually a plurality) temperature sensors For example, specifying whether analog data is to be calculated (based on which calculation is performed). The condition is also stored and held in the nonvolatile memory 10a, and the arithmetic combination management unit 13c calls the condition stored in the nonvolatile memory 10a at other timings when the power is turned on and holds it while the apparatus is in operation. And the condition currently hold | maintained at a predetermined timing is passed to the calculating part 13a. Further, for example, when a change in condition is received from the host computer or PLC via the communication data processing unit 17, the condition stored in the received content is updated, and the condition is also received from the nonvolatile memory 10a. Store the conditions and perform the update process. As a result, the latest conditions can be maintained whenever the power is turned off.

  The calculation unit 13a acquires information about the calculation method and data to be calculated from the calculation method management unit 13b and the calculation combination management unit 13c, acquires corresponding data from the data conversion processing unit 12, and holds the result. . The calculation result is given to the threshold value comparison processing unit 13d. Further, the communication data processing unit 17 is notified of the calculation result as necessary, for example, in accordance with a predetermined condition. The activation is executed based on an activation instruction issued with the time-up from the timer processing unit 14. When the arithmetic processing is completed, storage notification (registration) is made to the timer processing unit 14. As the calculation target data, each analog value stored in the volatile memory (RAM) 10 b is acquired via the data conversion processing unit 12.

  The threshold value comparison processing unit 13d reads the threshold value from the nonvolatile memory 10a and compares the calculation result data sent from the calculation unit 13a with the threshold value. If the current value is greater than the threshold, the status notification processing unit 13f is notified. Further, a threshold serving as a reference for the comparison process is set by the threshold change processing unit 13e.

  When the threshold value change processing unit 13e receives the change of the threshold value transmitted from the host PLC 1 or the management computer 7 through the communication data processing unit 17, the threshold value change processing unit 13e notifies the threshold value comparison processing unit 13d of the threshold value to be changed. While changing the threshold value during operation, the threshold value changing process is also performed for the nonvolatile memory 10a. Thus, management is performed so that the threshold data is not erased even after the power is turned off.

  When the status notification processing unit 13f receives the status abnormality notification from the threshold comparison processing unit 13d, the status notification processing unit 13f notifies the external status management 15 accordingly.

  Calculation parameters including information (calculation method, target data) and the like managed by the calculation method management unit 13b and the calculation combination management unit 13c can be stored and managed as, for example, an instance having the data structure shown in FIG. This instance is appropriately created as necessary, and when there are a plurality of target data, the corresponding instance is prepared. The example shown in FIG. 4 is a calculation parameter for two data (Data1, Data2). When there are four temperature sensors 5 as in the present embodiment and it is desired to perform all operations on the analog data from the four temperature sensors 5 at the same time, instances corresponding to combinations of the number of Data are required. . That is, a total of six instances of a combination of ch1-ch2, a combination of ch1-ch3, a combination of ch1-ch4, a combination of ch2-ch3, a combination of ch2-ch4, and a combination of ch3-ch4 (excluding reverse calculation) is required.

  The calculation method managed by the calculation method management unit 13 is managed by “calculation choice” in FIG. 4, and is set by selecting a predetermined one from the calculation expressions prepared in advance. As shown in the figure, there are various types of operations such as logical operations as well as four arithmetic operations.

  The calculation combination management unit 13c selects any two pieces of data from the four analog data by appropriately setting the path information stored in the “Data Path 1” and “Data Path 2” fields, and the calculation target data It is what.

  Furthermore, the calculation result in the calculation unit 13a is stored in the “Calculation Value” of the instance, and the threshold value changed / set by the threshold value change processing unit 13e is stored in the “Threshold Calculation Value”. Then, the threshold comparison processing unit 13d performs threshold processing on the threshold value stored in the “Threshold Calculation Value” and the calculation result given from the calculation unit 13a according to the determination condition stored in the “Calculation Status”.

  Next, the actual operation / action of the above-described apparatus (each processing unit or the like) will be described. FIG. 5 is a flowchart for pre-setting / tuning. Prior to actual monitoring, the flowchart shown in FIG. 5 is executed to make initial settings and the like.

First, the calculation method of the analog data between apparatus apparatuses is determined (S11). For example, if the relative temperature of the same device (measurement object 6) is compared as in the present embodiment, and the temperature difference opens, if that device is a system object that seems to be abnormal ,
Calculation method = AB
Set.

Also, if it seems that some abnormality can be detected by knowing the total temperature value of both in the system operating with different devices,
Calculation method = A + B
And set. In addition, various calculation methods such as quotient, product, logical sum, logical product, and exclusive logical sum can be selected as necessary. By executing the processing step of S11, the item “Calculation choice” of the instance shown in FIG. 4 is determined.

  Next, target data for calculation by the calculation method set in S11 is specified. In other words, it designates which device device from among the device devices (such as the temperature sensor 5) connected to the slave 10 is to perform arithmetic processing, and is specified by the channel number to which the device device is connected. .

For example, if you want to know the error between all terminals based on input 1 (1ch) in a 4-point input,
Specification 1: Input 1-Input 2
Specification 2: Input 1-Input 3
Specification 3: Input 1-Input 4
The three types are specified.

If you want to know the three types of operations, sum, product, and difference between two points (input 1 and input 2),
Specification 1 Input 1 + Input 2
Specification 2 Input 1 * Input 2
Specification 3 Input 1-Input 2
The three types are specified. By executing the processing step of S12, the item “Data Path1, Data Path2” of the instance shown in FIG. 4 is determined.

  S11. A threshold value for warning is determined for the calculation result obtained by executing the calculation using the calculation method and calculation target data set in the processing step of S12 (S13). For example, when it is desired to warn when the total temperature value exceeds 1000 ° C., the threshold is set to 1000 ° C. In addition, the threshold for setting a warning when the temperature difference between the apparatuses is opened by 3 degrees or more is set to 3 ° C. By executing the processing step of S13, the item “Threshold Calculation Value” of the instance shown in FIG. 4 is determined.

  Thereafter, the system is operated (S14), and the calculation result and status are confirmed at a predetermined timing (S15). This apparatus can always refer to “Calculation Value” as a calculation result and “Calculation Status” for specifying whether or not the threshold is exceeded (status abnormality). Moreover, the designation | designated destination and threshold value which specify the data of calculation object are changed as needed (S16).

  FIG. 6 shows the relationship between analog data conversion processing and arithmetic processing. In the present embodiment, the analog data conversion process is performed based on the occurrence of an interrupt (S21). This interrupt is started by, for example, an external hardware interrupt, or by a timer interrupt based on the timer processing unit 14 (a method of entering a conversion process on the assumption that analog conversion has ended when a certain timer expires). For example, or sensing an analog conversion process end flag (a method of entering the analog conversion process after confirming the end of analog conversion by periodically checking the flag).

  Next, a count value (analog data) is acquired from the hardware (temperature sensor 5) via the data acquisition driver 11, and passed to the data conversion processing unit 12 (S22). The data conversion processing unit 12 converts the acquired analog data into data (physical quantity) that can be understood by the user (S23), passes the converted data to the arithmetic processing unit 13, and requests an arithmetic processing based on the data (S23). S24). This calculation processing request executes the flowchart shown in FIG. Thereafter, the interruption is completed, and the next interruption is waited for (S25).

  In this example, the calculation function processing request is processed in the interrupt. However, if it is desired to reduce the interrupt time as much as possible, the following method can be used. That is, in this interrupt request process, only the conversion process request flag is set. Then, the flag is separately referred to in the main process, and if the conversion request flag is ON, the arithmetic function process is performed at a place other than the interrupt process.

  As shown in FIG. 7, the specific processing of the calculation function processing request first specifies an input channel for calculation (S31, S32). Here, the Data Path for specifying the storage destination of the calculation target data is specified with reference to the nonvolatile memory 10a (or the calculation combination management unit 13c). Next, the calculation method is designated (S33). That is, the Calculation Choice, which is a method for performing arithmetic processing using the two data specified in S31 and S32, is specified with reference to the nonvolatile memory 10a (or the arithmetic method management unit 13b). And based on the information which received the designation | designated, the calculation between two inputs A and B is performed (S34), and the obtained calculation result is stored. These processes are performed by the calculation unit 13a.

  Then, the threshold value comparison processing unit 13d reads the threshold value stored in the nonvolatile memory 10a and compares it with the calculation result obtained by the calculation unit 13a by executing S34 (S35), and whether or not the calculation result is larger than the threshold value. Is determined (S36). Here, in order to determine that the operation is abnormal when the calculation result is larger than the threshold value, the branch determination is made. However, the reverse may be possible depending on the specification. If the result of the branch determination in S36 is greater than the threshold, the status is turned on (S37), and if it is smaller, the status is turned off (S38). ON / OFF of these statuses is also stored in the nonvolatile memory 10a.

  By storing the above status, a series of processes for one operation is completed. However, since the internal processing flow shown in FIG. 7 is a flow for one operation, when there are a plurality of operations, the next operation processing 2 is started after the operation processing 1 is completed, and the same processing is performed.

  The specific processing of S15 and S16 in FIG. 5 is performed according to the flow shown in FIG. In other words, in the calculation result and status confirmation processing step of S15, as shown in FIG. 8, a current value read command is given from the user (external). At this time, since at least one of the calculation result and the status is designated as a read target, the designated target is read from the nonvolatile memory 10a and output.

  On the other hand, when the change destination step of S16 and the threshold value change step receives a request for changing related parameters (change request given via the communication data processing unit in FIG. 3) as shown in FIG. (Designation destination, calculation method, threshold value) is recognized, and the changed data is rewritten in the corresponding storage area of the nonvolatile memory 10a. Of course, although not shown, the information held by the calculation method management unit 13b, the calculation combination management unit 13c, and the threshold value change processing unit 13e is also updated according to the contents of the change.

  Next, a specific application executed using the above-described apparatus will be described. In this example, the presence / absence of abnormality of the controlled object 6 is determined based on analog data (temperature) output from the temperature sensor 5. As a premise, the controlled objects 6 are of the same type, and in normal conditions, the temperatures generated from the controlled objects during operation are the same. However, the specific temperature generated may vary depending on ambient conditions (temperature, humidity, etc.) and operating conditions (running at full power, driving at low load, etc.).

  Under such a premise, the temperatures of the control objects 6 acquired from the four temperature sensors 5 are compared, and if there is something different from the others, it can be estimated that there is an abnormality (failure). In order to make this determination, as a calculation method, a difference between two data is taken, and when the difference opens more than a certain value, an algorithm for determining that an abnormality has occurred (status ON) is set. Yes. In other words, the arithmetic expression in “Calculation Choice” in FIG. 4 is set to use “Data2-Data1” of 4, and is determined to be abnormal in consideration of the measurement error, the allowable range of fluctuation, etc. in “Threshold Calculation Value”. A threshold value (for example, 0.2 ° C.) is set, and “Calculate Status” is set to “1”.

  Thus, for example, if the temperatures (ch1 temperature, ch2 temperature, ch3 temperature, ch4 temperature) output from each temperature sensor 5 fluctuate as shown in FIG. 9, the calculation unit 13a calculates the temperature difference between the two data. Is obtained as shown in FIG.

  The threshold value comparison unit 13d compares the temperature difference between the two data shown in FIG. 9 with the threshold value (0.02 ° C.) in order to sequentially acquire the data from the calculation unit 13a. Then, since the difference does not exceed 0.2 ° C. until August 1, 200 *, it is determined that there is no abnormality. And since 200 * October 1st, since it exceeds 0.2 degreeC, a status notification is output. In addition, when two temperature values are simply compared and the difference is 0.2 ° C. or more, it can be determined that an abnormality has occurred, but it cannot be determined which temperature sensor has a different temperature. . However, when there are outputs from three or more (four in this example) temperature sensors 5 as in the present embodiment, temperature differences based on temperatures acquired at the same time are compared with each other. Can be identified. That is, as shown in FIG. 10, in the difference data of 200 * October 1, the temperature difference related to ch1 exceeds 0.2 ° C., and the measured values of the remaining three temperature sensors 5 are within the allowable range. It is in. Therefore, it can be determined that the temperature sensor of ch1 is abnormal.

  When such a situation occurs, the threshold comparison processing unit 13d notifies the status notification processing unit 13f of a status abnormality (turns the status ON). Upon receiving this, the status notification processing unit 13f notifies the host PLC 1 or the like as communication data via the status management unit 15 or the communication data processing unit 17. The status flag stored and held in the PLC 1 is also given to the management computer 7. As a result, the upper side can determine that it is the time for the regular maintenance of ch1 only by looking at the status flag. In addition, the calculation result can be actually confirmed as communication data. In this case, it can be confirmed how much deviation has occurred.

  Furthermore, according to the same principle, maintenance for correcting the shift between channels due to secular change can be facilitated. That is, although the temperature is regularly measured, it is conceivable that a deviation occurs in the reference temperature value due to a secular change or the like. An error exceeding the allowable range can be automatically notified as a status.

  Furthermore, it is possible to detect a change in temperature due to aging or destruction / deterioration of a controlled object at an early stage and preventive maintenance. That is, in an application for periodically measuring temperature, when a deviation occurs in the measured temperature value due to aging of the control target or device deterioration, it is possible to automatically notify the status of the temperature difference exceeding the allowable range as a status.

  In these cases, the two measured analog data are not compared with each other, but each analog data is compared with a reference value (reference temperature value). Therefore, for example, “Data 1−reference temperature value” can be used as an arithmetic expression.

  Further, in each of the above-described examples, it is specifically specified which one is abnormal, and the notification is made. However, the present invention is not limited to this, and at least one is in a state of fear of abnormality / abnormality. In this case, the abnormal status bit may be turned on to notify the user.

  In order to perform such processing, for example, as shown in FIG. 11, when the change of the difference is observed with the threshold values of a plurality of parameters (three in the illustrated example) being the same value, the threshold values are exceeded for each of the three parameters. Status (individual status 1 to 3). Thereby, an individual situation is known, and the presence or absence of abnormality of each parameter can be recognized by displaying the individual status. Then, a representative status that obtains an OR of these individual statuses is obtained. The bit of this representative status is turned on when any one of the representative statuses exceeds a threshold value, and therefore an algorithm that notifies when any one of the statuses becomes abnormal can be realized by performing notification based on the representative status.

  If the status in FIG. 11 is, for example, the difference between two analog data obtained by measurement, it can be applied to the above-described embodiment, and if it is one analog data obtained by measurement. By setting the base point as the reference temperature, it can be applied to the above-described modification. In the example shown in FIG. 10, the threshold value is set to the same value for all parameters, but the threshold value may be set for each parameter.

  In the above-described embodiments, any two of the four points (calculation of subtraction between input channels) based on analog data (four points of input in the embodiment) fetched from the outside. By detecting, errors between inputs were detected, and status notifications, etc., were made when thresholds were exceeded. In the present invention, the present invention is not limited to this, and it can be widely used for other applications by expanding the data range to be handled.

That is, in the above embodiment, the values of the two points at which the calculation is performed are all analog values fetched from outside, but in the present embodiment, the value to be calculated is not limited to the analog value, and the internal value is It was made possible to use it for arithmetic values.
As an example, as a multi-input operation,
Operation result X = (input 1 + input 2) −input 3
When it is desired to perform the calculation, the calculation 1 and the calculation 2 are used as shown in FIG. 12, and the calculation result X is calculated by the calculation 2. As a designation method, the path designation in the computation 2 is set to “calculation result 1”. Thus, by executing the calculation 1, the input 1 + input 2 is performed and the calculation result 1 is obtained. Then, by executing the calculation 2, the calculation result 1-input 3 is executed, which is equivalent to (input 1 + input 2) -input 3, and the calculation result X can be obtained.

As another example, calculation with a user-specified value can be performed. In other words, since the lower digits of the inputs 1 to 4 are shaken, the lower 2 bits are ignored (fixed to 0).
Operation result X = Input 1 AND User specified value (0xFFFC)
It can respond by executing. In the above example, the value is described in 16-bit expression. In this case, as an implementation method, only the operation 1 shown in FIG. 13 is used. That is, the designation method is set as a user designation value, and the user designation value is set to 0xFFFC (= 1111111111111100) (bit). Assume that the value of the analog input 1 is 0xA973 (this specified value is set by the user).

Then, it becomes as follows,
Analog input value: 0xA973 = 1010100101110011
User specified value: 0xFFFC = 111111111111111100
AND calculation result: 0xA970 = 1010100101110000
By performing AND calculation, a calculation result of a desired arithmetic expression can be obtained.

  In the above-described example, as the data other than the measured analog data, the calculation result (the result of the calculation process is used to feed back and used as the calculation value again) and the user specified value (the value to be calculated are calculated by the user). However, the present invention is not limited to this, and various other values processed inside the microcomputer can be used as operation values.

  In order to realize the above processing function, for example, as shown in FIG. 13, it is possible to respond by changing the contents of the buffer specified as the Data Path based on the “user specified value change request”. That is, by changing the reference destination data, the data used when performing the arithmetic processing by the designated arithmetic method becomes the user-specified value (including the arithmetic result) instead of the analog data. The embodiment described above can be applied as it is.

  In each of the above-described embodiments and modifications, the temperature sensor is used as an analog device, and the analog data is temperature. However, the present invention is not limited to this, and the frequency and other various analog data (changes due to abnormality, etc.) Can be used).

It is a figure which shows one Embodiment of the monitoring system which concerns on this invention. It is a figure which shows an example of the network system of the slave which concerns on this invention. 3 is a diagram illustrating an internal structure of an arithmetic processing unit 13. FIG. It is a figure which shows an example of the data structure of the instance for data calculation stored in a non-volatile memory. It is a flowchart which shows the function of a prior setting and tuning. It is a flowchart which shows an analog conversion processing function. It is a flowchart which shows the specific algorithm of a calculation function process request. It is a flowchart which shows the function of tuning and data reading. It is a figure explaining an effect | action. It is a figure explaining an effect | action. It is a figure explaining an effect | action. It is a figure explaining other embodiment. It is a figure explaining other embodiment. It is a figure explaining other embodiment.

Explanation of symbols

1 PLC
2 Master unit 3 Field network 5 Temperature sensor 6 Control object 7 Management computer 10 Slave 11 Data acquisition driver 12 Data conversion processing unit 13 Calculation processing unit 13a Calculation unit 13b Calculation method management unit 13c Calculation combination management unit 13d Threshold comparison processing unit 13e Threshold Change processing unit 13f Status notification processing unit 14 Timer processing unit 15 Status management unit 16 Communication driver 17 Communication data processing unit 18 Hardware processing unit 19 Main processing unit

Claims (7)

A plurality of analog devices that output analog data as input data are connected, and communicate with the controller via a network.
An arithmetic means for designating two of the plurality of analog devices, using analog data of the designated analog devices, and performing preset arithmetic processing;
Comparing means for comparing the calculation result obtained by the calculating means with a threshold value and determining whether or not the notification condition is satisfied;
A slave comprising means for outputting a determination result by the comparison means to the network.   The slave according to claim 1, wherein the arithmetic processing is to obtain a difference between the plurality of analog data.   The calculation means is configured to perform predetermined processing based on a calculation result obtained by performing calculation processing between analog data of two designated analog devices and analog data of any one of the plurality of analog devices. The slave according to claim 1 or 2, wherein the slave performs an operation.   4. The apparatus according to claim 1, wherein the computing unit designates a plurality of combinations of the two analog devices, and performs a predetermined computing process for each designated group. 5. Slave. The calculation means designates a plurality of combinations of the two analog devices, and performs a predetermined calculation process for each designated set,
The comparison means has a function of comparing the calculation result for each set with a threshold value to obtain an individual status as to whether or not the threshold value is exceeded, and obtaining a representative status based on each individual status. The slave according to any one of claims 1 to 4. An analog device that outputs analog data as input data is connected, and is a slave that communicates with the controller via a network.
Analog data acquired from the analog device, arithmetic means for performing arithmetic processing set in advance using data held in the slave,
Comparing means for comparing the calculation result obtained by the calculating means with a threshold value and determining whether or not the notification condition is satisfied;
A slave comprising means for outputting a determination result by the comparison means to the network. In a system in which the slave according to any one of claims 1 to 6 and a controller are connected via a network,
The monitoring system, wherein the controller recognizes that the notification condition is satisfied by acquiring the determination result of the slave.

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