JP7375977B1 - Programmable logic controller, support device, display device, logging method, support method, and display method - Google Patents

Abstract

An object of the present invention is to appropriately collect values of variables used in controlling equipment using a PLC.
[Solution] A control unit performs control processing, including program execution processing for executing a control program for controlling external equipment, and logging processing for collecting values of variables used in the control program, every control cycle. Repeat. The control unit divides a plurality of variables used in a control program into a plurality of control cycles, and collects the values of some of the plurality of variables in each of the plurality of control cycles. The value of is collected within a collection period that is longer than the control period.
[Selection diagram] Figure 11

Description

The present invention relates to a programmable logic controller (PLC) technology.

Regarding PLC, a technique is known that makes it easier to specify the temporal relationship between various data input from monitoring equipment and device values (see, for example, Patent Document 1). A technique is also known that allows logging to be performed without affecting the execution of user applications or the control of devices (see, for example, Patent Document 2). PLCs equipped with a scheduler are also known (for example, see Patent Document 3).

JP2020-13526A Patent No. 7188631 Japanese Patent Application Publication No. 2008-146357

With the PLCs of Patent Document 1 and Patent Document 2, it is difficult to collect a large amount of data indicating the operating status of the device and the PLC while suppressing the influence on the control of the device.

In one aspect, the present invention aims to appropriately collect values of variables used in controlling equipment by PLC.

According to one embodiment, a programmable logic controller includes a controller. The control unit repeats the control process every control cycle. The control process includes a program execution process that executes a control program for controlling external equipment, and a logging process that collects values of variables used in the control program.

The control unit divides a plurality of variables used in a control program into a plurality of control cycles, and collects the values of some of the plurality of variables in each of the plurality of control cycles. The value of is collected within a collection period that is longer than the control period.

According to another embodiment, the programmable logic controller repeats the control process every control cycle. The control process includes a program execution process that executes a control program for controlling external equipment, and a logging process that collects values of variables used in the control program.

A programmable logic controller divides multiple variables used in a control program into multiple control cycles based on setting information output from a support device, and divides some of the variables in each of the multiple control cycles. Collect variable values. Thereby, the programmable logic controller collects the values of each of the plurality of variables within a collection period that is longer than the control cycle.

The support device includes a program analysis section, a selection section, a reception section, and a setting information output section. The program analysis section analyzes the control program and extracts variables used in the control program. The selection unit selects a plurality of variables used in the control program from among the extracted variables. The reception department accepts the designation of the collection period. The setting information output unit outputs information indicating a plurality of variables used in the control program and information indicating a collection period as setting information.

According to yet another embodiment, the programmable logic controller repeats the control process every control cycle. The control process includes a program execution process that executes a control program for controlling external equipment, and a logging process that collects values of variables used in the control program.

A programmable logic controller divides a plurality of variables used in a control program into a plurality of control periods, and collects values of some of the variables in each of the plurality of control periods. Thereby, the programmable logic controller collects the values of each of the plurality of variables within a collection period that is longer than the control cycle.

A display device that displays information collected by a programmable logic controller includes a display section. The display unit displays the values of each of the plurality of variables in association with the collection time of each value of the plurality of variables during the collection period.

According to one aspect, values of variables used in controlling equipment by PLC can be appropriately collected.

It is a diagram showing an example of the configuration of a PLC system. It is a figure which shows the example of the execution period of each process which PLC performs. It is a figure showing an example of a collection period. It is a diagram showing an example of the hardware configuration of a PLC. It is a diagram showing an example of the hardware configuration of a PC. It is a figure showing an example of functional composition of a support device. FIG. 3 is a diagram illustrating an example of a method for setting conditions for executing logging processing. This is an example of a UI screen. FIG. 3 is a diagram showing an example of a data structure of logging setting data. FIG. 3 is a diagram illustrating an example of a data structure of collection target setting information. It is a figure showing an example of functional composition of PLC. It is a figure explaining the example of the logging execution method by PLC. 12 is a flowchart illustrating an example of processing contents of logging processing and storage processing. FIG. 3 is a diagram showing an example of a data structure of logging collection data. FIG. 3 is a diagram showing an example of a data structure of collected data. 3 is a flowchart illustrating an example of synchronous collection processing. 3 is a flowchart illustrating an example of asynchronous collection processing. It is a diagram showing an example of the hardware configuration of a collected data display device. FIG. 2 is a diagram showing an example of a functional configuration of a collected data display device. FIG. 3 is a diagram illustrating an example of a method of displaying collected data. FIG. 3 is a diagram illustrating an example of program display processing. This is an example of a display screen for collected data. This is an example of a warning screen. FIG. 3 is a diagram illustrating an example of waveform display processing. This is an example of a waveform display screen of collected data. FIG. 3 is a diagram illustrating an example of logging file analysis/conversion processing. FIG. 3 is a diagram illustrating an example of display control processing.

Hereinafter, embodiments will be described in detail with reference to the drawings.

PLC is a control device that controls manufacturing equipment, transport equipment, inspection equipment, etc. in factory automation. PLCs control various control devices by executing user application programs created by users, such as ladder programs.

When an abnormality occurs in the control of equipment by a control device such as a PLC, it is desirable to identify the cause of the abnormality. In addition, there is a desire to record information related to control of equipment and to verify the information afterward, not only in the case of occurrence of such an abnormality. Therefore, the user may set conditions in the control device in advance for keeping a data history, and based on these conditions, the control device may log data indicating the operating status of the equipment and the control device itself. .

In the PLC of Patent Document 1, input processing, program execution processing for executing a user application program, output processing, and logging processing are executed in order in each control cycle. However, when the control cycle becomes longer due to the addition of logging processing following input processing, program execution processing, and output processing, the start of the next control cycle is delayed. Therefore, the user application may not operate as intended by the user.

In the PLC of Patent Document 2, although the control cycle does not become longer due to the addition of logging processing, the amount of logged data may be limited in order to suppress the extension of the control cycle.

FIG. 1 shows an example of the configuration of a PLC system. The PLC system in FIG. 1 includes a PLC 1, a personal computer (PC) 2, an input/output module 3, and a communication module 4. PLC1 and PC2 are connected via a communication cable 6. The PLC 1 centrally controls various control devices installed in factories and the like.

The PC2 provides a function as a support device that supports the PLC1. The PC 2 is used, for example, to edit a user application program. The user application program corresponds to a control program for controlling external equipment. Note that in the following description, the user application program may be referred to as a "user program."

The user program may be created using, for example, a ladder language compliant with IEC (International Electrotechnical Commission) 61131-3. The user program may be created using a graphical programming language such as a motion program in a flowchart format such as a Sequential Function Chart (SFC). The user program may be created using a high-level programming language such as the C language.

Furthermore, as will be described later, the PC 2 also provides a function for setting conditions for executing logging processing.

The PLC 1, the input/output module 3, and the communication module 4 are connected via a communication bus 7. A plurality of input/output modules 3 and a plurality of communication modules 4 may be connected to the communication bus 7. The input/output module 3 and the communication module 4 are removable. The input/output module 3 and the communication module 4 correspond to external devices.

The input/output module 3 converts a signal from a servo amplifier, an encoder, or a sensor into an electrical signal, and may input/output a digital signal or an analog signal.

Communication module 4 provides a communication interface with other devices.

FIG. 2 shows an example of the execution period of each process executed by the PLC 1 in the PLC system of FIG.

The PLC 1 repeats control processing including input processing, program execution processing, output processing, logging processing, and system processing every control cycle. The input process is a process of capturing input data received from the input/output module 3. The program execution process is a process of executing a user program created by a user. In the execution of this user program, input data captured through input processing is used. The output process is a process of controlling the input/output module 3 by outputting the execution result of the user program, and causing the execution result to be reflected in the output of the input/output module 3.

The logging process is a process of collecting values of variables used in a user program and generating collected data. The logging process is also a process of recording data indicating the operating state of each component of the PLC system including the PLC 1 and saving it as a history. System processing is processing for managing the operation of the PLC 1 itself and maintaining proper operation.

The PLC 1 executes the logging process after the output process in each control cycle so as not to interfere with the execution of the user program. The control cycle is the total execution period of input processing, program execution processing, output processing, logging processing, and system processing. Therefore, the execution period of the logging process is limited by the control cycle band. The control period is specified by the user, for example.

FIG. 3 shows an example of a collection period used in the PLC system of FIG. 1. The collection period in FIG. 3 is longer than the control cycle, and includes the execution period of a plurality of logging processes. The execution period of each logging process is included in each of a plurality of control cycles. Therefore, within the collection period, a plurality of variables to be collected are divided into logging processes for each of a plurality of control cycles, and the values of the variables are collected asynchronously with the control cycles.

This makes it possible to collect variable values in a desired amount of data without affecting the execution period of input processing, program execution processing, and output processing related to user program and device control. Therefore, values of variables used in controlling the equipment can be appropriately collected.

Note that the execution period of the logging process may be adjustable by changing the ratio of the execution period of each of the program execution process, system process, and logging process.

Next, PLC1 and PC2 in the PLC system will be explained in more detail.

First, the hardware configuration of the PLC 1 will be described with reference to the example hardware configuration shown in FIG. The PLC 1 in FIG. 4 includes a communication I/F 11, a CPU (Central Processing Unit) 12, a bus controller 13, a memory 14, and a storage device I/F 15. All of these components are hardware, connected to the internal bus 16, and are capable of exchanging data with each other. "I/F" is an abbreviation for interface. A CPU is sometimes called a processor.

The communication I/F 11 is connected to the communication cable 6 and manages the exchange of various data with the PC 2.

The CPU 12 executes various programs such as a user program, a system program for managing the operation of the PLC 1 itself, and a logging execution program.

The bus controller 13 is connected to the communication bus 7 and manages the exchange of various data between the input/output module 3 and the communication module 4.

The memory 14 is, for example, a semiconductor memory, and includes a RAM (Random Access Memory) area and a ROM (Read Only Memory) area. The RAM area is used as a storage area for temporarily storing various data when the CPU 12 executes various programs. The ROM area is an area where various programs and data are stored, and for example, nonvolatile memory is used.

The storage device I/F 15 manages writing and reading processing of various data to and from an external storage device 17 such as a memory card.

Next, the hardware configuration of the PC 2 will be described with reference to the example hardware configuration shown in FIG. The PC 2 in FIG. 5 includes a CPU 21, a memory 22, an input device 23, a display device 24, an auxiliary storage device 25, and a communication I/F 26. All of these components are hardware and are connected to the internal bus 27, so that they can exchange data with each other.

The CPU 21 provides a user program editing function and a function for setting conditions for executing logging processing, for example, by executing a predetermined program using the memory 22.

The input device 23 is, for example, a keyboard, a pointing device, or the like, and is used to input instructions or information from the user.

The display device 24 is used, for example, to make inquiries or instructions to the user, and to display and output processing results.

The auxiliary storage device 25 is a magnetic disk device, an optical disk device, a magneto-optical disk device, etc., and may be, for example, a hard disk drive or a flash memory. The PC 2 can store programs and data in the auxiliary storage device 25 and load them into the memory 22 for use.

The communication I/F 26 is connected to the communication cable 6 and manages the exchange of various data with the PLC 1.

<Logging settings>

Next, a method of setting conditions for executing logging processing in the PLC 1 in the PLC system of FIG. 1 will be described.

First, FIG. 6 will be explained. FIG. 6 is a diagram showing an example of the functional configuration of the support device 30. This configuration example is an example in which the support device 30 provides a function of setting conditions for execution of logging processing by the PLC 1. In the PLC system, the PC 2 provides the functions of the support device 30 by causing the PC 2 to execute a predetermined setting tool program.

In FIG. 6, the support device 30 includes a program analysis section 31, a selection section 32, a reception section 33, a setting information output section 34, a calculation section 35, and a data amount output section 36. It is assumed that the control cycle for causing the PLC 1 to perform control processing is set in advance in the support device 30 by the user.

The program analysis unit 31 analyzes a user program to be executed by the PLC 1 and extracts a plurality of variables used in the user program.

The selection unit 32 selects a plurality of variables used in the user program from among the extracted variables as variables to be collected.

The accepting unit 33 accepts a designation of a collection period that is longer than the control cycle. The setting information output unit 34 outputs information indicating a plurality of variables to be collected and information indicating a collection period as setting information.

The PLC 1 divides the plurality of variables to be collected into a plurality of control cycles based on the setting information output from the support device 30, and divides some of the variables among the plurality of variables to be collected in each of the plurality of control cycles. Collect the value of . Thereby, the PLC 1 collects the values of each of the plurality of variables to be collected within the collection period.

The calculation unit 35 determines the number of control cycles in which the values of the plurality of variables to be collected are divided and collected based on the collection period and the control cycle. Then, the calculation unit 35 calculates the amount of data of the values of some variables collected in each of the plurality of control periods, based on the total amount of data of the values of each of the plurality of variables and the number of the plurality of control periods.

The data amount output unit 36 outputs the data amount of the values of some variables collected in each of a plurality of control cycles.

According to the support device 30, it is possible to cause the PLC 1 to execute a process of collecting variable values of a desired amount of data without affecting the control of the device. Therefore, values of variables used in controlling the equipment can be appropriately collected.

A method for setting conditions for executing logging processing, which is an example of a support method performed by the support device 30 having the configuration shown in FIG. 6, will be described in more detail with reference to FIG.

The support device 30 is equipped with a setting tool 40. In the PC 2, the function of the setting tool 40 is provided by causing the CPU 21 to execute a predetermined setting tool program.

Project data 41 is input to the setting tool 40 . The project data 41 is information including information on the system configuration of the PLC system, a user program to be executed by the PLC 1, and function setting information regarding the input/output module 3, communication module 4, etc. included in the PLC system. Here, it is assumed that the project data 41 has already been created by the user by executing a predetermined project data editing program on the PC 2, and is already stored in the auxiliary storage device 25, for example.

The setting tool 40 first performs collection target setting processing on the project data 41 in S110. This process is a process that sets variables to be logged from variables used in the user program, and is a process that provides the functions of the program analysis unit 31 and selection unit 32 in the support device 30 in FIG. be.

The process of S110 includes the program analysis process of S111. The program analysis process is a process of analyzing a user program included in the project data 41 and extracting a plurality of variables used in the user program. In the collection target setting process of S110, a process of having the user select variables to be collected by the logging process performed by the PLC 1 from the variables extracted by executing the program analysis process is further performed.

Now, FIG. 8 will be explained. FIG. 8 shows an example of a UI (User Interface) screen 100 used in the collection target setting process of S110.

In the screen example of FIG. 8, the UI screen 100 includes a program selection section 101, an extracted variable display section 102, and a target variable display section 103. When the PC 2 in FIG. 5 provides the functions of the support device 30, the display device 24 displays the UI screen 100.

Information indicating the user program included in the project data 41 is displayed in the program selection section 101. In this embodiment, it is assumed that a task is configured as a collection of a plurality of programs, and a user program is configured as a collection of a plurality of tasks. In the screen example of FIG. 8, "Application name" is the name of the user program, "Task 1", "Task 2", and "Task 3" are the names of each task, "Program", "Program N" is the name of each program belonging to each task. In this screen example, the relationship between the user program, each task, and each program is expressed in a tree format.

When the user performs an operation to select one of the program names displayed in the program selection section 101, the program analysis process of S111 is performed on the program corresponding to the selected name. The variables that are specified are extracted. Note that when an operation is performed to select a task name instead of a program name, variables are extracted from each of the programs belonging to the task corresponding to the selected name. At this time, the names of the extracted variables are displayed in a list on the extracted variable display section 102.

When the user selects one or more of the variable names displayed in the extracted variable display area 102 and presses the registration button 104, the variable corresponding to the selected name will be collected. Identified as a variable. At this time, the names of the identified variables to be collected are displayed in a list on the target variable display section 103.

Note that when the user selects one or more of the names of the variables to be collected displayed in the target variable display section 103 and presses the release button 105, the name corresponding to the selected name is selected. The variable is excluded from the variables to be collected.

Furthermore, when the user presses the batch registration button 106, all the variables whose names are displayed in the extracted variable display section 102 are selected as variables to be collected, and their names are displayed in the target variable display section 103. A list will be displayed. On the other hand, when the user presses the batch release button 107, all variables whose names are displayed in the target variable display section 103 are excluded from the variables to be collected.

In addition, in the collection target setting process of S110, the total amount of data that will be collected when the logging process is executed for all of the collection target variables selected as described above is calculated based on the project data 41. The obtained total data amount is displayed on the collected data size display section 108 on the UI screen 100.

The control cycle preset by the user is displayed on the control cycle display section 109 on the UI screen 100.

Returning to the explanation of FIG. 7. In S120, collection operation setting processing is performed. This process is a process that creates information for setting the operation of the logging process, and is a process that provides the function of the reception unit 33 in the support device 30 of FIG. 6. This information allows the PLC 1 to set, for example, the collection timing of variable values that are the data to be collected, the collection period for data collection, the storage timing for the PLC 1 to save the collected data in the external storage device 17, etc. It will be done.

When the user performs an operation to specify a collection period, the specified collection period is accepted and displayed on the collection period display section 110 on the UI screen 100.

Following the processes of S110 and S120 described above, a setting content confirmation process of S130 is performed. This process is a process that determines whether the execution time of the control process when the PLC 1 executes the logging process for all the variables to be collected selected in the process of S110 falls within the preset control cycle. be. This process further provides the functions of the calculation unit 35 and data amount output unit 36 in the support device 30 of FIG.

In this process, for example, execution times of input processing, program execution processing, output processing, and system processing in the control processing executed by the PLC 1 are calculated from the project data 41. The sum of these execution times is then subtracted from the control period. The time obtained by this subtraction is the time during which the logging process can be executed, and this time will be referred to as the "maximum processing time."

Next, based on this maximum processing time, the amount of data that can be collected within this time is determined as the maximum size that can be collected in the control cycle. Then, a comparison is made between this maximum size and the total data amount calculated in the process of S110 (the value displayed on the collected data size display section 108 on the UI screen 100), and the total data amount is less than or equal to the maximum size. It is determined whether or not.

If the total amount of data exceeds the maximum size, it becomes possible to select a setting box 112 that enables logging asynchronously to the control cycle.

When the user performs an operation to select the setting box 112, the CPU 21 in FIG. 5 operates as the calculation unit 35 and determines the number of divisions of the collection period based on the collection period and the control cycle. The number of divisions represents the number of control cycles in which the values of each of the plurality of variables to be collected are divided and collected. The CPU 21 can calculate the number of divisions, for example, by dividing the collection period by the control period.

Next, the CPU 21 determines the data size that can be collected in the control cycle based on the total data amount and the number of divisions displayed on the collected data size display section 108. The data size that can be collected in a control cycle represents the amount of data of values of some variables that are collected in each of a plurality of control cycles. The CPU 21 can calculate the data size that can be collected in a control cycle, for example, by dividing the total data amount by the number of divisions.

In the example of FIG. 8, the control period is 1 ms and the acquisition period is 200 ms, so the number of divisions is 200 ms/1 ms=200. Also, the total amount of data is 400kW. W represents the number of words. In this case, the data size that can be collected in the control cycle is 400kW/200=2kW.

The data size that can be collected in a control cycle is displayed on the data size display section 111 on the UI screen 100. Of the 2kW/30kW displayed on the data size display section 111, 2kW is the data size that can be collected in the control cycle, and 30kW is the maximum size that can be collected in the control cycle. In this case, the display device 24 in FIG. 5 operates as the data amount output unit 36 and displays the data size that can be collected in the control period on the UI screen 100.

By displaying the control cycle, collection period, collection data size, and data size that can be collected in the control cycle on the UI screen 100, it becomes possible to remind the user to consider the variables to be collected, for example.

Next, a setting file creation process of S140 is performed. This setting file creation process is a process that provides the function of the setting information output unit 34 in the support device 30 of FIG. The communication I/F 26 in FIG. 5 operates as the setting information output section 34.

The configuration file creation process is a process that outputs, as logging configuration data 42, the information specifying the variable to be collected selected in the process of S110 and the operation setting information of the logging process set in the process of S120. The logging setting data 42 corresponds to the setting information output by the setting information output unit 34. The logging setting data 42 is transferred to the PLC 1, and in the PLC 1, operation settings for logging processing are performed based on the contents of the logging setting data 42.

The logging setting data 42 will be further explained. FIG. 9 shows an example of the data structure of the logging setting data 42.

The logging setting data 42 includes project data information 51, collection operation setting information 52, and collection target setting information 53.

The project data information 51 is information that specifies the user program to be executed by the PLC 1, and includes information such as the name (project name) given to the object code obtained by compiling the user program and the execution date and time of the compilation. include. Note that the project data information 51 is included as part of the project data 41.

The collection operation setting information 52 is information created by the collection operation setting process in S120. The collection operation setting information 52 includes, for example, collection timing, a collection period specified by the user, and a collection method. Collection timing represents the timing at which the collection period starts.

The collection method is information indicating synchronous or asynchronous. Synchronous is a collection method that performs logging in synchronization with the control cycle, and asynchronous is a collection method that performs logging asynchronously with the control cycle. If the setting box 112 in FIG. 8 is selected, asynchronous is set as the collection method; otherwise, synchronous is set as the collection method.

The collection operation setting information 52 also includes information specifying the storage timing at which the PLC 1 stores the collected data in the external storage device 17 and the storage destination external storage device 17 in which the collected data is stored.

The collection target setting information 53 is information about the collection target variable selected by the collection target setting process in S110. An example of the data structure of the collection target setting information 53 is shown in FIG.

In the example of FIG. 10, the collection target setting information 53 includes information on the total size of collected data at the data collection timing. Furthermore, the collection target setting information 53 includes information on the number of variables to be collected. Furthermore, the collection target setting information 53 includes information on memory type, data type, memory address, and data size as information about each variable to be collected. These pieces of information specify the location on the memory 14 of the storage area used to hold the values of the variables to be collected when the user program is executed in the PLC 1.

Setting of the conditions for execution of the logging process by the PLC 1 is performed by the support device 30 by using the setting tool 40 described above.

<Execution of logging>

Next, a logging process performed by the PLC 1 in accordance with conditions set by the PC 2 as the support device 30 in the PLC system of FIG. 1 will be described.

First, FIG. 11 will be explained. FIG. 11 is a diagram showing an example of the functional configuration of the PLC 1 that performs logging processing. In the configuration example shown in FIG. 11, the PLC 1 includes a control section 61.

The control unit 61 repeats control processing including input processing, program execution processing, output processing, logging processing, and system processing every control cycle. The control unit 61 divides the plurality of variables to be collected into a plurality of control periods based on the logging setting data 42 output from the support device 30, and divides the plurality of variables to be collected into a plurality of control periods in each of the plurality of control periods. Collect values of some variables. Thereby, the control unit 61 collects the values of each of the plurality of variables to be collected within the collection period. In the hardware configuration example shown in FIG. 4, the CPU 12 operates as the control unit 61.

According to such a PLC 1, it is possible to collect the values of variables of a desired amount of data without affecting the control of the equipment. Therefore, values of variables used in controlling the equipment can be appropriately collected.

The logging execution method performed by the PLC 1 including the components shown in FIG. 11 will be described in further detail using FIG. 12. The processes of S220, S250, S260, S270, and S280 are performed by the control unit 61.

The program execution process of S220 is a process of executing a user program using the input data sent from the input/output module 3 and the communication module 4, which was captured in the input process. This execution result is output by output processing for controlling the input/output module 3 and the communication module 4. In the hardware configuration example of FIG. 5, the CPU 12 that executes this program execution process uses the storage area of the memory 14 for executing the user program. The storage area used at this time will be referred to as the program use area 14a.

The logging process of S250 is a process of collecting values of variables to be collected among the variables used in the user program executed by the program execution process of S220. It is assumed that the logging setting data 42 including information about the variables to be collected and operation setting information of the logging process is created as described above in the support device 30 (PC2) and provided to the PLC 1 in advance. .

The time management process in S260 and the collection timing detection process in S270 are performed in parallel with control processes including input processing, program execution processing, output processing, logging processing, and system processing. The time management process is a process of measuring the current time. The collection timing detection process is a process of detecting the arrival of the data collection timing indicated by the collection operation setting information 52 included in the logging setting data 42.

In the logging process of S250, the process of collecting the values of the variables to be collected is performed in response to the detection of the arrival of the collection timing by the collection timing detection process. In addition, in the logging process, a process is performed in which the collection time of the variable value is acquired from the time measurement result by the time management process, and the collected data in which the variable value and the collection time are associated with each other is stored in the ring buffer 62.

The ring buffer 62 is a storage area that stores collected data in which the collection time of the variable value through logging processing is associated with the variable value collected at that collection time, each time the variable value is collected. In the hardware configuration example shown in FIG. 4, a ring buffer 62 is configured by a part of the storage area of the memory 14.

Further, the CPU 12 of the PLC 1 executes the storage process of S280. This storage process includes a process of detecting the arrival of the storage timing indicated by the collection operation setting information 52 included in the logging setting data 42. In addition, this storage process is performed by controlling the storage device I/F 15 to read the collection data stored in the ring buffer 62 in response to the detection of the arrival of the storage timing. This includes processing for saving the data in the external storage device 17, which is the storage destination.

Here, the logging process in S250 and the storage process in S280 will be explained in more detail using the flowchart shown in FIG.

In FIG. 13, the processes of S258 and S259 represent the details of the storage process, and the remaining processes of S251 to S257 represent the details of the logging process.

The processing shown in FIG. 13 is started when the processing start timing of the logging processing arrives in the control processing of each control cycle.

First, in S251, a process is performed to determine whether or not the collection timing has been detected by the collection timing detection process in S270 described above. In this determination process, when it is determined that the arrival of the collection timing has been detected (when the determination result is YES), in S252, the collection method included in the collection operation setting information 52 of the logging setting data 42 is asynchronous. Processing is performed to determine whether or not.

When the collection method is asynchronous (when the determination result is YES), asynchronous collection processing in S253 is performed, and when the collection method is synchronous (when the determination result is NO), synchronous collection processing in S254 is performed. will be held.

In the determination process of S251, when it is determined that the arrival of the collection timing is not detected (when the determination result is NO), in S255, the collection method included in the collection operation setting information 52 of the logging setting data 42 is asynchronous. A process is performed to determine whether or not there is one.

When the collection method is asynchronous (when the determination result is YES), in S256, values are collected for all the collection target variables whose information was included in the collection target setting information 53 of the logging setting data 42. A process is performed to determine whether or not the In this determination process, when it is determined that there are variables to be collected whose values have not yet been collected (when the determination result is NO), the asynchronous collection process of S257 is performed.

In the determination process of S255, when the collection method is synchronous (when the determination result is NO), the process shown in FIG. 13 ends. In the determination process of S256, when it is determined that values have been collected for all of the variables to be collected (when the determination result is YES), the process shown in FIG. 13 ends.

In the asynchronous collection process of S253, the synchronous collection process of S254, and the asynchronous collection process of S257, the values of the variables to be collected are collected, and the collected values are stored in the ring buffer 62 as collected data 73, which will be described later.

Following the asynchronous collection process in S253, the synchronous collection process in S254, or the asynchronous collection process in S257, in S258 it is determined whether the storage timing indicated by the collection operation setting information 52 included in the logging setting data 42 has arrived. A process is performed to determine whether the In this determination process, when it is determined that the storage timing has arrived (when the determination result is YES), the process advances to S259. On the other hand, in this determination process, when it is determined that the storage timing has not arrived (when the determination result is NO), the process shown in FIG. 13 ends without performing the process of S259.

In S259, a process is performed to read the collected data 73 stored in the ring buffer 62 by the asynchronous collection process of S253, the synchronous collection process of S254, or the asynchronous collection process of S257 in the logging process currently being executed. In S259, processing is also performed to save the read collected data 73 as the logging collected data 70 in the storage destination external storage device 17 indicated by the collection operation setting information 52.

The logging collection data 70 will be further explained. FIG. 14 shows an example of the data structure of the logging collection data 70.

The logging collection data 70 includes project data information 51, the number of collection data 71, the collection data size 72, and one or more collection data 73.

The project data information 51 is information that specifies the user program executed by the PLC 1, and includes, for example, the name given to the object code obtained by compiling the user program, and information on the execution date and time of the compilation. That is, the project data information 51 included in the logging collection data 70 is similar to the project data information 51 included in the logging setting data 42. The CPU 12 reads the project data information 51 from the logging setting data 42 and incorporates it into the logging collection data 70 in the asynchronous collection process of S253, the synchronous collection process of S254, and the asynchronous collection process of S257.

The number of collected data 71 is information representing the number of pieces of collected data 73 included in the logging collected data 70. Further, the collected data size 72 is information representing the total amount of collected data 73 included in the logging collected data 70.

The logging collected data 70 includes, as collected data 73, data about the values of collected variables in the order in which they were collected. An example of the data structure of this collected data 73 is shown in FIG.

In the example of FIG. 15, the collected data 73 includes time stamp information. This timestamp represents the time when the value of the variable was collected.

In addition, the collected data 73 includes variable data representing the respective values of one or more variables collected at the time of the timestamp. ” is included.

In the process of S259, the logging collection data 70 having such a data structure is created using the logging setting data 42 and the collection data 73 stored in the ring buffer 62, and is stored in the external storage device 17. be exposed.

When the process of S259 ends, the process shown in FIG. 13 ends. According to the process of FIG. 13, when the collection method is asynchronous, the asynchronous collection process of S257 is performed even if the arrival of the collection timing is not detected in S251. Therefore, following the asynchronous collection process in S253, the asynchronous collection process in S257 is repeated every control cycle. This makes it possible to collect variable values asynchronously with the control cycle.

Note that when the logging process shown in the flowchart of FIG. 13 is completed, the CPU 12 also performs a process of further saving the logging setting data 42 in the external storage device 17. This logging setting data 42 is used when displaying collected data 73, which will be described later.

Next, the synchronous collection process of S254 in FIG. 13 will be described in more detail using the flowchart shown in FIG.

First, in S261, a process is performed to start measuring the execution time of the logging process for the control process in the current control cycle.

Next, in S262, a process is performed in which the current time measured by the time management process in S260 described above is obtained as a timestamp, and the obtained timestamp is written into the ring buffer 62 as a timestamp of the collected data 73. .

Next, in S263, the current value of each variable to be collected is acquired, and the acquired value is associated with the variable to be collected as variable data following the writing position of the time stamp of the collected data 73. The process of writing to the ring buffer 62 is performed in a predetermined order.

The value of the variable to be collected is specified based on the information on the memory type, data type, memory address, and data size regarding the variable to be collected, which is included in the collection target setting information 53 of the logging setting data 42. It is held at a position above the program use area 14a. Therefore, in the process of S263, the value of the variable to be collected is acquired by reading the data held at this position, and written to the ring buffer 62.

Next, in S264, a process is performed to determine whether the execution time of the current logging process whose measurement was started in the process of S261 is within the maximum processing time described above. In this determination process, when it is determined that the execution time of the current logging process is within the maximum processing time (when the determination result is YES), the process advances to S265. On the other hand, in this determination process, when it is determined that the execution time of the current logging process does not fall within the maximum processing time (when the determination result is NO), the current collection process ends. Note that for the purpose of speeding up the process, the process in S264 is performed when it is determined that values have been collected for all the variables to be collected (when the determination result is YES) in the determination process in S265, which will be described next. ) may be performed after.

In S265, a process is performed to determine whether values have been collected for all of the collection target variables whose information was included in the collection target setting information 53 of the logging setting data 42. In this determination process, when it is determined that values have been collected for all variables to be collected (when the determination result is YES), the current collection process ends. On the other hand, in this judgment process, if it is judged that there are variables to be collected whose values have not yet been collected (when the judgment result is NO), the process returns to S263 and the values have been collected. For variables to be collected that do not exist, processing is performed to collect their values.

When the above collection process is completed, the storage of the collected data 73 in the ring buffer 62 is completed, and then the process of S258 in FIG. 13 is performed.

Next, the asynchronous collection processing in S253 and S257 in FIG. 13 will be described in more detail using the flowchart shown in FIG.

First, in S271, a process is performed to start measuring the execution time of the logging process for the control process in the current control cycle.

Next, in S272, a process is performed to determine whether or not the asynchronous collection process in S253 has been started with the arrival of the collection timing in S251 in FIG. In this determination process, when it is determined that the asynchronous collection process in S253 has started (when the determination result is YES), the process advances to S273. On the other hand, in this determination process, when it is determined that the asynchronous collection process in S257 has been started (when the determination result is NO), the process advances to S278.

In S273, a process is performed in which the current time is acquired as a timestamp and the acquired timestamp is written into the ring buffer 62 as the timestamp of the collected data 73.

Next, in S274, the current value of each variable to be collected is acquired, and the acquired value is associated with the variable to be collected as variable data following the writing position of the time stamp of the collected data 73. The process of writing to the ring buffer 62 is performed in a predetermined order.

Next, in S275, a process is performed to determine whether values have been collected for all the collection target variables whose information was included in the collection target setting information 53 of the logging setting data 42. In this determination process, if it is determined that there remain variables to be collected whose values have not been collected (when the determination result is NO), the process advances to S276.

In S276, a process is performed to determine whether the execution time of the current logging process whose measurement was started in the process of S271 has reached a predetermined time. As the predetermined time, for example, the time specified by the user or the maximum processing time described above is used. In this judgment process, if it is judged that the execution time of the current logging process has not reached the predetermined time (when the judgment result is NO), the process returns to S274, and the collection target whose values have not been collected is A process is performed to collect the values of the variables.

On the other hand, in this determination process, when it is determined that the execution time of the current logging process has reached the predetermined time (when the determination result is YES), in S277, variable information indicating the last collected variable is Recording processing is performed. This variable information indicates the variable that was collected in the immediately preceding process of S274 among the collection target variables whose information was included in the collection target setting information 53 of the logging setting data 42.

In the determination process of S275, when it is determined that values have been collected for all the variables to be collected (when the determination result is YES), the process advances to S277.

In S278, processing is performed to identify the next variable to be collected. In the process of S278, for example, based on the variable information recorded in the previous asynchronous collection process, the variable following the last collected variable is specified as the next variable to be collected. If the last variable to be collected is the last variable to be collected, it is determined that there is no variable to collect next.

Next, in S279, a process is performed to determine whether values have been collected for all the collection target variables whose information was included in the collection target setting information 53 of the logging setting data 42. If it is determined in the process of S278 that there are no variables to be collected next, it is determined that values have been collected for all variables to be collected.

In the determination process of S279, if it is determined that there are still variables to be collected whose values have not been collected (when the determination result is NO), the processes from S274 onwards are performed for the next variable to be collected. will be held. Note that if it is desired to record the collection time of the value of the variable collected in the current asynchronous collection process, the processes from S273 onwards are performed for the next variable to be collected. When it is determined that values have been collected for all of the variables to be collected (when the determination result is YES), the current asynchronous collection process ends.

By repeating the processes after S273 or S274, variable information indicating the last collected variable is updated in S277. Therefore, variable information is information indicating variables collected during the period from the first control cycle to the current control cycle among multiple control cycles in which the values of each of the multiple variables to be collected are divided and collected. be. The current control cycle is an example of any control cycle.

When the above collection process is completed, the storage of the collected data 73 in the ring buffer 62 is completed, and then the process of S258 in FIG. 13 is performed.

<Display of collected data by logging>

Next, a method of displaying the collected data 73 obtained by the logging process performed by the PLC 1 in the PLC system of FIG. 1 will be described.

First, the hardware configuration of the device that displays the collected data 73 will be described. FIG. 18 shows an example of the hardware configuration of the collected data display device 80.

In the configuration example of FIG. 18, the collected data display device 80 includes a CPU 81, a memory 82, an input device 83, an auxiliary storage device 84, a display device 85, and a storage device I/F 86. All of these components are hardware, connected to an internal bus 87, and can exchange data with each other.

The CPU 81 provides a function of controlling various displays such as the display of collected data and the waveform display of the collected data, by executing a predetermined program using the memory 82, for example.

The input device 83 is, for example, a keyboard, a pointing device, or the like, and is used to input instructions or information from the user.

The auxiliary storage device 84 is a magnetic disk device, an optical disk device, a magneto-optical disk device, etc., and may be a hard disk drive or a flash memory, for example. The collected data display device 80 can store programs and data in the auxiliary storage device 84 and load them into the memory 82 for use.

The display device 85 is used, for example, to make inquiries or instructions to the user, and to display and output processing results.

The storage device I/F 86 manages reading processing of various data from the external storage device 17 such as a memory card.

The collected data display device 80 has the above hardware configuration. Note that since such a hardware configuration is a standard configuration of a general computer, the collected data display device 80 may be configured using such a computer. Further, the collected data display device 80 may be configured by further using the PC 2 that functions as the support device 30 in the PLC system of FIG.

Next, FIG. 19 will be explained. FIG. 19 is a diagram showing an example of the functional configuration of the collected data display device 80.

In the configuration example of FIG. 19, the collected data display device 80 includes a display section 91 and displays information collected by the PLC 1. The display device 85 in FIG. 18 operates as a display section 91.

The display unit 91 displays the values of each of the plurality of variables in association with the collection time of each value of the plurality of variables to be collected during the collection period.

According to such collected data display device 80, the value of the variable of the desired amount of data collected can be displayed in association with the time within the collection period without affecting the control of the device.

An example of a method for displaying collected data performed by the collected data display device 80 having the configuration shown in FIG. 19 will be described in further detail using FIG. 20.

The collected data display device 80 performs program display processing in S310, waveform display processing in S320, logging file analysis/conversion processing in S330, and display control processing in S340. Each of these processes is performed by the CPU 81 in FIG. A program that causes the CPU 81 to perform each of these processes is sometimes referred to as engineering software.

The program display process in S310 displays the user program included in the project data 41 described above, and also displays the values of variables to be collected for the user program using display data created from the logging collection data 70. It is processing. The display data includes collection time and variable values. Here, it is assumed that the project data 41 has already been created by the user by executing a predetermined project data editing program on the PC 2, and is already stored in the auxiliary storage device 84, for example.

The waveform display process of S320 is a process of displaying the relationship between the collection time and the value of the variable to be collected using a waveform using the display data created from the logging collection data 70.

The logging file analysis/conversion process at S330 analyzes the logging setting data 42 and the logging collection data 70, and converts the collected data 73 into display data that is input to each of the program display process at S310 and the waveform display process at S320. This is the process of converting it into It is assumed here that the logging setting data 42 and the logging collection data 70 are provided by the external storage device 17. In the logging file analysis/conversion process, these data are read from the external storage device 17 and used.

The display control process of S340 includes a process of providing the display data created by the logging file analysis/conversion process of S330 to the program display process of S310 and the waveform display process of S320. The display control process also includes a process of linking the display of the program display process and the waveform display process.

The details of each process shown in FIG. 20 performed by the collected data display device 80 will be further explained below.

First, details of the program display process in S310 will be explained using FIG. 21.

As shown in FIG. 21, the program display process in S310 includes the operation UI process in S311, the variable value display control process in S312, and the user program display process in S313.

The operation UI process in S<b>311 is a process of accepting input according to an operation on the input device 83 by the user of the collected data display device 80 .

The variable value display control process in S312 receives the input information accepted by the operation UI process in S311 and the interlocking information from the display control process in S340, and controls the display of variable values included in the display data. It is processing.

The user program display process of S313 displays the user program included in the project data 41, and also displays the value of the variable to be collected on the display of the user program under the control of the variable value display control process of S312. It is processing.

Here, FIG. 22 will be explained. FIG. 22 is an example of a display screen for collected data. This display screen is displayed on the display device 85 when the CPU 81 executes the program display process in S310.

The example screen in FIG. 22 shows a state in which a UI screen 120 obtained by the operation UI process in S311 is displayed over the user program display screen 113 obtained in the user program display process in S313.

Through the user program display process in S313, a diagram (for example, a ladder program) representing the contents of the user program included in the project data 41 is created and displayed as the user program display screen 113.

The UI screen 120 includes a frame-back button 121-1 and a frame-forward button 121-2 that give instructions to sequentially update the display of the values of variables collected at each collection time, a seek bar 122, and a button 122 for collecting the values of variables to be displayed. It has a time input field 123 for directly inputting the time. Note that the time input field 123 also has a function as a display field that displays the collection time specified by operating the frame return button 121-1, the frame forward button 121-2, or the seek bar 122.

Through the operation UI process in S311, the collection time specified in response to the operation of the frame-back button 121-1, the frame-forward button 121-2, or the seek bar 122 is acquired, and this time is displayed in the time input field 123. Further, when a time input operation is performed in the time input field 123, the input time is acquired as the specified collection time by this operation UI process.

Through the variable value display control process in S312, the value of the variable associated with the collection time in the logging collection data 70 and the designation of the collection time acquired through the operation UI process in S311 are acquired. Note that the logging collection data 70 is acquired by the logging file analysis/conversion processing in S330 and sent to the display control processing in S340, and the variable value display control processing requires the provision of the logging collection data 70 from the display control processing. receive. Also, through this variable value display control process, the value of the variable at the specified collection time is sent to the user program display process in S313, and the user program display process causes the value of the variable to be displayed on the user program display screen 113. It will be held in

In the screen example shown in FIG. 22, the ON/OFF display 114 and variable display 115 display values of variables.

The ON/OFF display 114 displays the element in a different color depending on the state indicated by the variable value when the state of a program component having either ON or OFF state is selected as a variable to be collected. The variable value is represented by a filled-in display. In the screen example of FIG. 22, the elements to be collected in the user program are displayed in black as the ON/OFF display 114, but in reality, for example, if they are "ON", they are displayed in red, or , in the case of "OFF", the element is displayed in blue.

The variable display 115 directly displays the numerical value as a variable value when a numerical value regarding a program component is selected as a variable to be collected.

As described above, through the processes of S311, S312, and S313, as shown in the screen example of FIG. 22, the collection time and the value of the variable collected at that collection time are associated and is displayed.

Furthermore, the program display process in S310 further includes a verification process in S314 and a warning process in S315.

The verification process in S314 is a process of verifying the project data 41, the logging setting data 42, and the project data information 51 of the logging collection data 70.

The warning process of S315 is a process of issuing a predetermined warning when the project data information 51 of each data does not match as a result of the collation process of S314.

FIG. 23 shows an example of a warning screen displayed on the display device 85. A predetermined warning in the warning process of S315 is performed by displaying such a warning screen on the display device 85, for example. This example screen includes a warning dialog 130 that warns the user that the project data information 51 does not match. Note that, since this is useful when debugging a user program, for example, the collected data display device 80 allows the function of displaying variable values to be used even if the project data information 51 does not match.

Next, details of the waveform display processing in S320 will be explained using FIG. 24.

As shown in FIG. 24, the waveform display process in S320 includes the operation UI process in S321, the variable value display control process in S322, and the waveform creation process in S323.

The operation UI process of S321 is similar to the process of S311, and is a process of accepting input according to the operation on the input device 83 by the user of the collected data display device 80.

The variable value display control process in S322 is similar to the process in S312, and receives input information accepted by the operation UI process in S321 and the above-mentioned linked information from the display control process in S340, and displays This process controls the display of variable values included in the data.

The waveform creation process of S323 is a process of creating and displaying a waveform representing the relationship between the collection time and the variable based on the display data provided by the display control process of S340.

Here, FIG. 25 will be explained. FIG. 25 is an example of a waveform display screen 140 of collected data. This waveform display screen 140 is displayed on the display device 85 when the CPU 81 executes the waveform display process in S320.

The waveform 141 included in the waveform display screen 140 is created by the waveform creation process in S323. In the screen example of FIG. 27, the waveforms 141 for each of "variable 1," "variable 2," and "variable 3" are displayed using a solid line, a broken line, and a dashed-dotted line, respectively. Further, a time display 142 included in the waveform display screen 140 represents the collection time at which the relationship with the variable value is expressed by the waveform 141, and is displayed on the waveform display screen 140 by the waveform creation process of S323. .

Furthermore, when an instruction to move the collection time range is accepted through the operation UI process in S321, the waveform 141 for the post-move collection time range is displayed on the waveform display screen 140 through the waveform creation process in S323. Furthermore, the acquisition time indicated by the thick line 143 displayed on the waveform display screen 140 is displayed in the time display field 144 by the waveform creation process of S323.

The variable value display control process of S322 acquires the value of the variable associated with the collection time in the display data provided by the display control process of S340. Furthermore, the collection time displayed in the time display column 144 is acquired through the variable value display control process in S322. Further, by this variable value display control processing, the value of the variable at the acquired collection time is displayed in the variable value display column 145 as the value of the variable represented by the position of the intersection of the waveform 141 and the thick line 143.

As described above, through the processes of S321, S322, and S323, as shown in the screen example of FIG. 25, the collection time and the value of the variable collected at that collection time are correlated and is displayed.

Next, details of the logging file analysis/conversion process in S330 will be explained using FIG. 26.

As shown in FIG. 26, the logging file analysis/conversion process in S330 includes the logging setting data acquisition process in S331, the logging collection data acquisition process in S332, and the display data creation process in S333.

The logging setting data acquisition process of S331 is a process of importing the logging setting data 42 from the external storage device 17.

The logging collection data acquisition process of S332 is a process of reading and importing the logging collection data 70 from the external storage device 17.

The display data creation process in S333 is a process for creating display data including collection times and variable values from the logging setting data 42 and the logging collection data 70.

Next, details of the display control process in S340 will be explained using FIG. 27.

As shown in FIG. 27, the display control process in S340 includes the variable value providing process in S341, the playback control process in S342, and the collected data acquisition process in S343.

The variable value providing process in S341 uses the display data created by the logging file analysis/conversion process in S330 as the value of the variable associated with the collection time, and performs the program display process in S310 and the waveform display process in S320. This is a process provided to

The playback control process in S342 is a process in which, upon receiving a predetermined linkage instruction, the program display process in S310 and the waveform display process in S320 are controlled to link the contents of the screen displayed by each process. Through this playback control process, for example, a process is performed in which the collection time specified by the operation on the UI screen 120 in the example screen of FIG. 22 and the collection time indicated by the thick line 143 in the example screen of FIG. 25 are made the same time. be exposed.

The collected data acquisition process at S343 is a process for acquiring display data created by the logging file analysis/conversion process at S330 and providing it to the variable value providing process at S341.

As described above, the display control process in S340 provides the display data created by the logging file analysis/conversion process in S330 to the program display process in S310 and the waveform display process in S320.

Although the disclosed embodiments and their advantages have been described in detail above, those skilled in the art can make various changes, additions, and omissions without departing from the scope of the present invention as clearly stated in the claims. Will.

1 PLC
2 PCs
3 Input/output module 4 Communication module 6 Communication cable 7 Communication bus 11, 26 Communication I/F
12, 21, 81 CPU
13 Bus controller 14, 22, 82 Memory 14a Program use area 15, 86 Storage device I/F
16, 27, 87 Internal bus 17 External storage device 23, 83 Input device 24, 85 Display device 25, 84 Auxiliary storage device 30 Support device 31 Program analysis section 32 Selection section 33 Reception section 34 Setting information output section 35 Calculation section 36 Data Volume output section 40 Setting tool 41 Project data 42 Logging setting data 51 Project data information 52 Collection operation setting information 53 Collection target setting information 61 Control section 62 Ring buffer 70 Logging collection data 71 Number of collection data 72 Collection data size 73 Collection data 80 Collection Data display device 91 Display section 100, 120 UI screen 101 Program selection section 102 Extracted variable display section 103 Target variable display section 104 Registration button 105 Cancel button 106 Bulk registration button 107 Bulk cancellation button 110 Collection period display section 111 Data size display section 112 Setting box 113 User program display screen 114 ON/OFF display 115 Variable display 120 UI screen 121-1 Frame return button 121-2 Frame forward button 122 Seek bar 123 Time input field 130 Warning dialog 140 Waveform display screen 141 Waveform 142 Time display 143 Thick line 144 Time display field 145 Variable value display field

Claims (9)

comprising a control unit that repeats a control process for each control cycle, including a program execution process for executing a control program for controlling an external device, and a logging process for collecting values of variables used in the control program;
The control unit divides a plurality of variables used in the control program into a plurality of control cycles, and collects values of some variables among the plurality of variables in each of the plurality of control cycles, A programmable logic controller characterized in that values of each of the plurality of variables are collected within a collection period that is longer than the control cycle. The control unit records variable information indicating variables collected during a period from a first control cycle among the plurality of control cycles to any one of the plurality of control cycles, and 2. The programmable logic controller according to claim 1, wherein in the next control cycle, values of variables that have not yet been collected among the plurality of variables are collected based on the variable information. The control unit measures the execution time of the logging process in any of the control cycles, and ends the logging process in any of the control cycles when the execution time of the logging process reaches a predetermined time. The programmable logic controller according to claim 2, characterized in that: A support device for a programmable logic controller,
The programmable logic controller performs a control process, including a program execution process for executing a control program for controlling an external device, and a logging process for collecting values of variables used in the control program, in each control cycle. Repeatedly, based on the setting information output from the support device, a plurality of variables used in the control program are divided into a plurality of control cycles, and a part of the plurality of variables is divided in each of the plurality of control cycles. By collecting the values of the variables, the values of each of the plurality of variables are collected within a collection period longer than the control cycle,
The support device includes:
a program analysis unit that analyzes the control program and extracts variables used in the control program;
a selection unit that selects a plurality of variables used in the control program from among the extracted variables;
a reception department that accepts the designation of the collection period;
a setting information output unit that outputs information indicating a plurality of variables used in the control program and information indicating the collection period as the setting information;
A support device characterized by comprising: The number of the plurality of control periods is determined based on the collection period and the control period, and the number of the plurality of control periods is determined based on the total data amount of the values of each of the plurality of variables and the number of the plurality of control periods. a calculation unit that calculates the amount of data of the values of some of the variables collected in each cycle;
a data amount output unit that outputs a data amount of values of the some of the variables collected in each of the plurality of control cycles;
The support device according to claim 4, further comprising:. A control process including a program execution process of executing a control program for controlling an external device and a logging process of collecting the values of variables used in the control program is repeated every control cycle, and the control process By dividing a plurality of variables used in a plurality of control cycles into a plurality of control cycles, and collecting values of some of the plurality of variables in each of the plurality of control cycles, the values of each of the plurality of variables can be calculated. a programmable logic controller that collects data within a collection period that is longer than the control cycle;
a display device that displays the values of each of the plurality of variables in association with the collection time of each of the values of the plurality of variables during the collection period;
A programmable logic controller system comprising: The programmable logic controller repeats control processing, including program execution processing for executing a control program for controlling external equipment, and logging processing for collecting the values of variables used in the control program, in each control cycle. ,
The programmable logic controller divides a plurality of variables used in the control program into a plurality of control cycles, and collects values of some of the variables in each of the plurality of control cycles. , a logging method characterized in that the values of each of the plurality of variables are collected within a collection period that is longer than the control cycle. 8. The logging method according to claim 7, wherein the display device displays the values of each of the plurality of variables in association with collection times of the values of each of the plurality of variables during the collection period. The programmable logic controller repeats control processing, including program execution processing for executing a control program for controlling external equipment, and logging processing for collecting the values of variables used in the control program, in each control cycle. , divides a plurality of variables used in the control program into a plurality of control periods based on setting information output from a support device of the programmable logic controller, and divides a plurality of variables used in the control program into a plurality of control periods, and divides the plurality of variables in each of the plurality of control periods. By collecting the values of some of the variables, the values of each of the plurality of variables are collected within a collection period longer than the control cycle,
The support device is
Analyzing the control program and extracting variables used in the control program,
Display the extracted variables,
identifying a plurality of variables selected from the displayed variables as a plurality of variables used in the control program;
Accepting the specification of the collection period,
outputting information indicating a plurality of variables used in the control program and information indicating the collection period as the setting information;
A support method characterized by :

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