JP6783034B1 - Programmable logic controllers, computers, methods, and programs - Google Patents

Abstract

The program execution unit (120) included in the programmable logic controller (100) repeatedly executes a program created by using a sequential function chart, which is a programming language for the programmable logic controller (100). The index information storage unit (140) is included in the program and stores step information that uniquely identifies the step that describes the process executed by the programmable logic controller (100). The trace execution unit (150) records a log including step information and information for specifying the number of execution cycles, which is the number of times the program execution is repeated, each time the program execution unit (120) executes a step. To do.

Description

The present invention relates to programmable logic controllers, computers, methods, and programs.

The programmable logic controller controls the device to be controlled by executing each instruction of the control program in each execution cycle. SFC (Sequential Function Chart) is one of the programming languages for describing the control program executed by the programmable logic controller. The control program described in the SFC describes a step that describes the process executed by the programmable logic controller, and a transition condition for shifting to the step. For example, in the example shown in FIG. 11, after step 0 is executed, step 1 is executed when the transition condition 1 is satisfied, and step 2 is executed when the transition condition 2 is satisfied. After the step 1 is executed, the step 3 is executed when the transition condition 3 is satisfied. After step 2 is executed, step 3 is executed when the transition condition 4 is satisfied.

In order to debug the control program described in SFC, it is necessary to trace the execution order of steps, the number of executions of each step, and the like.

In Patent Document 1, in order to trace the control program described in SFC, every time the programmable logic controller executes a step in the program, data including the step number is accumulated in the trace data storage unit. It is described that the peripheral device reads from the trace data storage unit and displays the time chart of the execution route and the execution order of the transition step on the display.

Japanese Unexamined Patent Publication No. 2001-5504

In the configuration described in Patent Document 1, data including step numbers are sequentially accumulated, and based on the accumulated data, a time chart of the execution route and the execution order of the transition step is displayed on the display. It is possible to trace the execution order of steps from the obtained data, for example, from the start to the end of the trace. However, in the configuration described in Patent Document 1, the number of times the control program is executed and the step number are not stored in association with each other, and the executed steps are only displayed in a time chart. However, the control program actually used in the factory is a complicated control program including many transitions and steps, and in the technique described in Patent Document 1, the execution cycle of the control program is within the execution cycle. It was very difficult for the user who debugs the control program to grasp the execution order and the number of executions of the steps executed in.

The present invention has been made in view of the above circumstances, and an object of the present invention is to trace the execution path and the number of executions of a step of a program described in SFC in units of execution cycles.

In order to achieve the above object, the execution means provided in the programmable logic controller of the present invention is created by using a sequential function chart which is a programming language for the programmable logic controller, and a step describing the processing executed by the programmable logic controller. look including a plurality of blocks having the steps are repeatedly executed a program to be executed in parallel across blocks. Prior to the execution means executing the program , the assigning means generates step information that is information that uniquely identifies a step in the program, and assigns the generated step information to each step. The logging means is the number of execution cycles, which is the number of times the program is repeatedly executed with step information that identifies the executed step as a trace log indicating the execution path of the step while the execution means is executing the program. It is stored in the storage unit in association with. When the program is created, each block is assigned block identification information that identifies the block, each step is assigned in-block step identification information that identifies the step in the block, and the step information assigned to each step is , Information different from the in-block step identification information assigned to the step. The same step information is assigned by the assigning means, and the step identification information in the block unique to each block is assigned to the steps executed in parallel across the blocks.

Programmable logic controller of the present invention, stored as trace log indicating the execution path of the steps, the storage unit in association with the number of execution cycles the number of times that the step information identify the steps that have been executed execution program is repeated To do. By providing such a configuration, it is possible to trace the execution path and the number of executions of the steps of the program described in the SFC in units of execution cycles.

A block diagram showing a functional configuration of a programmable logic controller and a development tool according to an embodiment of the present invention. Block diagram showing the hardware configuration of the programmable logic controller and the development tool according to the embodiment The figure which shows an example of the control program which concerns on embodiment The figure which shows an example of the data stored in the index table which concerns on embodiment. The figure which shows an example of the trace log which concerns on embodiment Flowchart of index allocation processing according to the embodiment Flowchart of trace processing according to the embodiment The figure which shows the example of the display screen of the trace log which concerns on embodiment (the 1) The figure which shows the example of the display screen of the trace log which concerns on embodiment (the 2) The figure which shows the example of the display screen of the trace log which concerns on embodiment (the 3) The figure which shows the example of the display screen of the trace log which concerns on embodiment (the 4) The figure which shows the example of the display screen of the trace log which concerns on embodiment (the 5) The figure which shows another example of the display screen of the trace log which concerns on embodiment. The figure which shows the example of the screen which displays the timing chart of the trace log which concerns on embodiment. Diagram showing other examples of data stored in the index table The figure which shows an example of the program written in SFC

Hereinafter, the programmable logic controller 100 according to the embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment)
The programmable logic controller 100 shown in FIG. 1 executes a control program instruction according to an input signal supplied from a detector in a control system, a production system, or the like, supplies an output signal to the controlled device, and supplies the controlled device. To control. The detector is, for example, a sensor or a switch. The controlled device is, for example, an actuator, a solenoid valve, or an indicator light.

The programmable logic controller 100 (hereinafter referred to as PLC100) sequentially executes instructions from the first instruction to the last instruction of the control program, and when the last instruction is executed, the instructions are sequentially executed again from the first instruction. Executing the PLC100 from the first instruction to the last instruction of the control program is sometimes called scanning. The time during which the PLC 100 goes around the execution of the instruction of the control program is sometimes called the scan time.

In an embodiment, the PLC 100 executes a control program described in a sequential function chart (SFC). The PLC 100 has a function of tracing the execution path of a step during execution of a control program.

The development tool 500 is a personal computer in which a dedicated application program having a program creation function is installed. In addition to the program creation function, the development tool 500 has a function of displaying information indicating a step execution route based on the trace log recorded by the PLC 100.

As shown in FIG. 2, the PLC 100 has a hardware configuration of a non-volatile memory 11 for storing various programs and data, a volatile memory 12 for storing trace logs, a detector 801 and a controlled device 802, and data. It has an input / output interface 13 for sending and receiving, a connection interface 14 for communicating with the development tool 500, and an MPU (Micro Processing Unit) 15 for controlling the entire PLC 100. The non-volatile memory 11, the volatile memory 12, the input / output interface 13, and the connection interface 14 are connected to the MPU 15 via the bus 19 and communicate with the MPU 15.

The non-volatile memory 11 stores a program for realizing various functions of the PLC 100 and data used when the program is executed. For example, the non-volatile memory 11 stores the firmware that controls the MPU 15. In the embodiment, the functions of the firmware of the PLC 100 include a function of executing preprocessing necessary for executing the trace and a function of tracing the execution of the step of the user program 111. Further, the non-volatile memory 11 stores an application program. In the embodiment, the user program 111 is stored in the non-volatile memory 11. The non-volatile memory 11 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a flash memory, and a hard disk drive.

The user program 111 is a program developed by the user using SFC, and is a control program that enables the MPU 15 to realize a function of controlling a controlled device. The user is, for example, the administrator of PLC100.

The volatile memory 12 is used as a memory for storing the trace log. Further, the volatile memory 12 is used as a work memory of the MPU 15. The volatile memory 12 includes, for example, a RAM (Random Access Memory).

The input / output interface 13 is a connection interface for the PLC 100 to communicate with the detector 801 and the controlled device 802. The input / output interface 13 converts the data supplied from the MPU 15 into an electric signal, and transmits the converted signal to the controlled device 802 via the connection cable 701. Further, the input / output interface 13 restores the electric signal received from the detector 801 via the connection cable 701 into data and outputs the data to the MPU 15.

The connection interface 14, for example, includes a USB controller, converts the data supplied from the MPU 15 into an electric signal, and transmits the converted signal to the development tool 500 via the connection cable 702. Further, the connection interface 14 receives the electric signal output by the development tool 500 via the connection cable 702, restores the received electric signal to data, and outputs the received electric signal to the MPU 15. The connection cable 702 is, for example, a USB cable.

The MPU 15 executes various programs stored in the non-volatile memory 11 to realize various functions of the PLC 100. For example, the MPU 15 executes a user program 111 stored in the non-volatile memory 11 to perform an operation using the value indicated by the input signal supplied from the detector 801 and outputs an output based on the value indicating the operation result. The signal is supplied to the controlled device 802.

As a hardware configuration, the development tool 500 includes a memory 51 that stores various programs and data, an input device 52 that detects an input operation of a user, a display device 53 that displays an image, and a connection interface 54 that communicates with the PLC 100. And a CPU (Central Processing Unit) 55 that controls the entire development tool 500. The memory 51, the input device 52, the display device 53, and the connection interface 54 are connected to the CPU 55 via the bus 59 and communicate with the CPU 55.

The memory 51 includes a volatile memory and a non-volatile memory. The memory 51 stores a program for realizing various functions of the development tool 500 and data used when the program is executed. In the embodiment, the memory 51 stores the log display program 511. The log display program 511 is a program that enables the CPU 55 to display a trace log. Further, the memory 51 is used as a work memory of the CPU 55.

The input device 52 includes an input device such as a keyboard and a mouse, detects a user's input operation, and supplies a signal indicating the detected user's input operation to the CPU 55. The display device 53 includes a display and displays an image based on the signal supplied from the CPU 55 on the display.

The connection interface 54 includes, for example, a USB controller, converts data supplied from the CPU 55 into an electric signal, and transmits the converted signal to the PLC 100 via the connection cable 702. Further, the connection interface 54 receives the electric signal output by the PLC 100 via the connection cable 702, restores the received electric signal to data, and outputs the received electric signal to the CPU 55.

The CPU 55 executes various programs stored in the non-volatile memory 11 to realize various functions of the development tool 500. In the embodiment, the CPU 55 executes the log display program 511 and displays the trace log recorded by the PLC 100 on the display device 53.

Subsequently, the functional configuration of the PLC 100 will be described with reference to FIG. Functionally, the PLC 100 stores a program storage unit 110 that stores a control program, a program execution unit 120 that executes a control program, a trace preprocessing unit 130 that assigns an index to each step of the control program, and data related to the index. It includes an index information storage unit 140 to store, a trace execution unit 150 to trace the execution of a step, and a trace log storage unit 160 to store the trace log.

The program storage unit 110 stores a control program executed by the PLC 100 to control the controlled device. The control program corresponds to the user program 111 shown in FIG. The function of the program storage unit 110 is realized by the non-volatile memory 11 shown in FIG.

FIG. 3 shows an example of the user program 111. In the example shown in FIG. 3, the user program 111 includes a plurality of blocks. The block is, for example, a block that divides the processing executed by the PLC 100 into functional units.

The user program 111 described in SFC is executed as follows. Since the user program 111 includes a plurality of blocks, the user program 111 is processed in order from the block having the smallest block number to the block having the largest block number. Note that the scan does not process the steps of the inactive block. The active steps of the active block are processed in sequence.

An example of step processing will be described with reference to FIG. For example, assume that block 0 is active and step 0 of block 0 is active in the N (N is a positive integer) scan. In this case, step 0 of block 0 is executed. When step 0 of block 0 is executed, when the transition condition T02 between step 0 of block 0 and step 2 of block 0 is satisfied, step 0 of block 0 becomes inactive and block 0 Step 2 is activated. On the other hand, when the transition condition T02 is not satisfied, step 2 of block 0 remains in the inactive state, and step 0 of block 0 remains in the active state. For example, it is assumed that the transition condition T02 between step 0 of block 0 and step 2 of block 0 is satisfied. In this case, step 0 of block 0 becomes inactive and step 2 of block 0 becomes active.

Subsequently, if block 1 is in the active state, the active step of block 1 is executed, and if block 1 is in the inactive state, none of the steps of block 1 is executed. For example, assume that block 1 is in an active state and step 1 of block 1 is active. In this case, step 1 of block 1 is executed. When step 1 of block 1 is executed, when the transition condition T12 between step 1 of block 1 and step 3 of block 1 is satisfied, step 1 of block 1 becomes inactive and block 1 is executed. Step 3 is activated. On the other hand, when the transition condition T12 is not satisfied, step 1 of block 1 remains in the active state.

Subsequently, if the block 2 is in the active state, the active step of the block 2 is executed, and if the block 2 is in the inactive state, none of the steps of the block 2 is executed.

In the N + 1 scan, if block 0 is in the active state, the step in the active state of block 0 is executed. For example, assume that block 0 is in the active state and step 2 of block 0 is active. In this case, step 2 of block 0 is executed. When step 2 of block 0 is executed, for example, when the transition condition T04 between step 2 of block 0 and step 0 of block 0 is satisfied, step 2 of block 0 becomes inactive. Step 0 of block 0 is activated.

Subsequently, if block 1 is in the active state, the active step of block 1 is executed, and if block 1 is in the inactive state, none of the steps of block 1 is executed. Further, if the block 2 is in the active state, the active step of the block 1 is executed, and if the block 2 is in the inactive state, none of the steps of the block 1 is executed.

In the N + 2 scan, when block 0 is in the active state, the step in the active state of block 0 is executed. For example, assume that block 0 is in the active state and step 0 of block 0 is active. In this case, step 0 of block 0 is executed. When step 0 of block 0 is executed, for example, when the transition condition T02 between step 0 of block 0 and step 2 of block 0 is satisfied, step 0 of block 0 becomes inactive. Step 2 of block 0 is activated.

The program execution unit 120 shown in FIG. 1 executes the control program at each execution cycle. The function of the program execution unit 120 is realized by the MPU 15 shown in FIG. The program execution unit 120 is an example of the execution means of the present invention.

The trace preprocessing unit 130 shown in FIG. 1 assigns a unique number to a step in the control program stored in the program storage unit 110, and stores data indicating the correspondence between the step and the number in the index information storage unit 140. Specifically, the trace preprocessing unit 130 assigns a serial number unique to the user program 111 to each step of the user program 111 as shown in FIG. This serial number is called an index. The process of assigning an index to a step is sometimes called an index allocation process. The trace preprocessing unit 130 executes the index allocation process, for example, as a part of the initial process after the power is turned on. The function of the trace preprocessing unit 130 is realized by the MPU 15 shown in FIG. The trace preprocessing unit 130 is an example of the allocation means of the present invention.

The trace preprocessing unit 130 assigns an index to a step for the following reasons. As described above, the steps of the plurality of blocks of the user program 111 are executed in parallel in the same scan. Since the steps are executed across blocks, it is not possible to specify the execution path of the steps and the number of executions for each step by recording only the step numbers assigned at the time of creating the user program 111. ..

Further, in the user program 111, for example, there may be a plurality of blocks in which processing is grouped for each function. Since the step numbers indicating the steps are numbered within the blocks, there may be steps having the same step numbers in different blocks. In this case, if only the step number assigned when the user program 111 is created is recorded at the time of tracing, it is not possible to specify which block the step belongs to.

The index information storage unit 140 stores the index data assigned by the trace preprocessing unit 130. Specifically, the index information storage unit 140 has an index table 1401 as shown in FIG. In the index table 1401, the index assigned to the step specified by the block number and the step number is stored. The function of the index information storage unit 140 is realized by the non-volatile memory 11 shown in FIG. The steps in the control program are examples of the steps of the present invention. The index information storage unit 140 is an example of the step information storage means of the present invention. The data stored in the index table 1401 is an example of the step information of the present invention. The block number is an example of identification information that identifies the block of the present invention. The step number is an example of identification information that identifies a step within the block of the present invention.

The trace execution unit 150 shown in FIG. 1 traces the execution of the steps executed by the program execution unit 120, and stores the trace log in the trace log storage unit 160. The function of the trace execution unit 150 is realized by the MPU 15 shown in FIG. The trace execution unit 150 is an example of the logging means of the present invention.

Specifically, the trace execution unit 150 starts the trace when it receives the instruction to start the execution of the trace from the development tool 500. It is assumed that the trace execution unit 150 has a counter (hereinafter, scan counter) that counts the number of times the program execution unit 120 scans the control program. Hereinafter, the number of times the program execution unit 120 scans the control program may be referred to as the number of scans. The initial value of the scan counter is, for example, "1". When the traced step is the last step, the trace execution unit 150 adds, for example, 1 to the value of the scan counter.

When the program execution unit 120 executes a step, the trace execution unit 150 reads the index assigned to the step from the index table 1401 shown in FIG. 4, and in the scan indicated by the scan counter value, the step indicated by the index value. The log indicating that has been executed is stored in the trace log storage unit 160. The trace execution unit 150 stores the log in the trace log storage unit 160 each time the program execution unit 120 executes a step. Further, the trace execution unit 150 adds the value of the scan counter when the program execution unit 120 executes the last step of the control program. This is because the program execution unit 120 has completed one scan of the control program.

The trace log storage unit 160 stores data indicating the trace log recorded by the trace execution unit 150. FIG. 5 shows an example of the trace log stored in the trace log storage unit 160. In the illustrated example, the index of the executed step is sequentially recorded for each number of scans. The index on the far left indicates the first step performed in the scan, and the index on the far right indicates the last step performed in the scan. The function of the trace log storage unit 160 is realized by the volatile memory 12 shown in FIG. The number of scans included in the trace log is an example of information that identifies the number of execution cycles of the present invention.

As shown in FIG. 1, the development tool 500 functionally includes a trace execution instruction unit 510 that instructs the PLC 100 to execute a trace, a trace log reading unit 520 that reads data including a trace log from the PLC 100, and a trace log. Includes a display unit 530 that displays the trace result based on.

When the trace execution instruction unit 510 receives the instruction to start the trace execution from the user, the trace execution instruction unit 510 outputs the instruction to start the trace execution of the program to the PLC 100. Further, the trace execution instruction unit 510 receives an instruction from the user and issues an instruction to the PLC 100 to stop the execution of the trace. The function of the trace execution instruction unit 510 is realized by the input device 52 shown in FIG. 2, the connection interface 54, and the CPU 55.

When the trace log reading unit 520 receives an instruction to read the trace log from the user, the trace log and the data necessary for displaying the log are read from the PLC 100. Specifically, the trace log reading unit 520 stores the trace log stored in the trace log storage unit 160 of the PLC 100, the data of the index table 1401 stored in the index information storage unit 140, and the program storage unit 110. The stored control program is read, and the read control program is output to the display unit 530. The function of the trace log reading unit 520 is realized by the input device 52 shown in FIG. 2, the connection interface 54, and the CPU 55. The trace log reading unit 520 is an example of the reading means of the present invention.

When the trace log, the data of the index table 1401 and the control program are supplied from the trace log reading unit 520, the display unit 530 generates an image showing the trace result, and displays the generated image on the display device 53. indicate. The function of the display unit 530 is realized by the display device 53 shown in FIG. 2 and the CPU 55. The display unit 530 is an example of the display means of the present invention.

Next, a process in which the trace preprocessing unit 130 assigns an index to each step of the control program prior to tracing will be described. The trace preprocessing unit 130 executes the following index allocation process as a part of the initial process of the PLC 100.

As shown in FIG. 6, the trace preprocessing unit 130 assigns an index to the next step until an index is assigned to all the steps in the control program (step S11; No), and the index and the block number to which the step belongs are assigned. , The step number of the step is stored in the index table 1401 shown in FIG. 4 (step S12). When the trace preprocessing unit 130 assigns an index to all the steps in the control program (step S11; Yes), the trace preprocessing unit 130 ends the index allocation process. The above is the index allocation process.

Subsequently, the process of tracing the execution of the steps of the control program by the trace execution unit 150 will be described.

The trace execution unit 150 starts the trace process when the trace execution instruction unit 510 of the development tool 500 outputs the trace execution instruction according to the user's instruction. For example, after instructing the start of tracing from the development tool 500, the user switches the operation mode of the PLC 100 to the execution mode of the control program. Therefore, the program execution unit 120 starts executing the control program.

As shown in FIG. 7, when the trace execution unit 150 determines that the program execution unit 120 has executed the step (step S21; Yes), the trace execution unit 150 calculates the index of the executed step from the index table 1401. Read (step S22). Subsequently, the trace execution unit 150 reads the value of the current scan counter and acquires the current number of scans (step S23). The trace execution unit 150 records the step log in the trace log storage unit 160 as the step executed by the scan indicated by the current number of scans by using the index value read in step S22 (step S24).

The trace execution unit 150 determines whether or not the target step is the last step of the control program (step S25). If the step is the last step of the control program (step S25; Yes), the trace execution unit 150 adds the value of the scan counter (step S26), and if it is not the last step (step S25; No), the step. Execute S27.

In step S27, the trace execution unit 150 determines whether or not the trace stop instruction has been received from the development tool 500 (step S27). If the trace stop instruction has not been received (step S27; No), the trace execution unit 150 again executes the process of step S21. On the other hand, when the trace stop instruction is received (step S27; Yes), the trace execution unit 150 ends the trace process. The above is the trace process. As described above, when the trace execution unit 150 executes the trace processing, the log as shown in FIG. 5 is stored in the trace log storage unit 160 of the PLC 100.

Suppose the user gives an instruction to stop tracing and then instructs to display the trace log. In response to this, the trace log reading unit 520 reads the trace log, the data of the index table 1401 and the control program from the PLC 100. The trace log reading unit 520 outputs the read data to the display unit 530.

For example, it is assumed that the display unit 530 is supplied with the trace log as shown in FIG. In the illustrated example, step 0 of block 0 and step 0 of block 1 are executed in the first scan, and step 2 of block 0 and step 2 of block 1 are executed in the second scan. In the third scan, step 0 of block 0 and step 2 of block 1 are executed. The display unit 530 displays a screen as shown in FIG. 8A from the trace log of scan 1.

Here, the display unit 530 displays the user program 111 as shown in FIG. 8A so that the user can visually recognize that the step 0 of the block 0 indicated by the index 1 has been executed from the log of the first scan. Then, step 0 of block 0 is shaded. Further, the display unit 530 also displays the number of times step 0 of block 0 has been executed so far. In the illustrated example, since step 0 of block 0 has not been executed before the first scan, “1” is displayed as the number of executions in step 0 of block 0. In this way, the display unit 530 displays the number of times the step is executed in the vicinity of the step number. Therefore, the user can visually recognize how many times the step has been executed. Further, the display unit 530 displays the number of scans.

Now suppose the user presses the "next step" button. In response to this, the display unit 530 displays a screen as shown in FIG. 8B. In the illustrated example, the display unit 530 displays the step 0 of the block 1, which is the next executed step, in a shaded manner. Further assume that the user presses the "next step" button. In response to this, the display unit 530 displays a screen as shown in FIG. 8C. In the illustrated example, the display unit 530 displays step 2 of the block 0 in a shaded manner.

Now suppose the user presses the "next step" button. In response to this, the display unit 530 displays a screen as shown in FIG. 8D. In the illustrated example, the display unit 530 displays the step 2 of the block 1, which is the next executed step, in a shaded manner. Now suppose the user presses the "next step" button. In response to this, the display unit 530 displays a screen as shown in FIG. 8E. In the illustrated example, the display unit 530 displays the step 0 of the block 0, which is the next executed step, in a shaded manner. Since step 0 of block 0 is executed twice at the time of the second scan, "2" is displayed as the number of executions in step 0 of block 0.

Further, for example, when the user presses the "previous step" button while displaying FIG. 8E, the display unit 530 displays a screen showing the previously executed step as shown in FIG. 8D. indicate.

By displaying the trace log in such an manner by the development tool 500, the user can sequentially confirm the execution route of the steps. Further, the development tool 500 displays the number of times the step is executed in association with the step number. Therefore, the user can visually recognize how many times the step has been executed.

Further, as shown in FIG. 9A, the display unit 530 may display the steps executed for each scan on one screen. The display unit 530 shades step 0 of block 0 and step 1 of block 1 so that it can be visually recognized that step 0 of block 0 and step 1 of block 1 have been executed in one scan. Further, the display unit 530 displays a number indicating the order in which each step is executed. In the illustrated example, a screen showing the trace log of one scan is displayed. For example, when the user operates a pull-down, the display unit 530 displays a screen showing the trace log of the specified scan.

The display unit 530 can also display a timing chart as shown in FIG. 9B. In the illustrated example, the first to fourth scans are displayed, but the user can display the timing chart for the fifth and subsequent scans by moving the scroll bar B1. Further, in the illustrated example, steps 0 of block 0 to step 0 of block 2 are displayed, but the user can display the timing chart of the subsequent steps by moving the scroll bar B2. ..

The development tool 500 displays the trace log in such an manner, so that the user can confirm the progress of the execution of the step.

As described above, the PLC 100 according to the embodiment records the number of scans and the index that identifies the step in association with each other as a trace log. Therefore, the user can confirm the execution path and the number of executions of the steps of the program in units of execution cycles.

Since the PLC100 assigns a unique number to each step in the control program, the program is divided into a plurality of blocks for each functional unit, and there are steps in which the same number is assigned in different blocks. Even so, it is possible to trace the execution path and the number of executions of the step.

In addition, by using the index as the step information for specifying the step to be recorded in the trace log, for example, the memory capacity required to store the trace log can be determined rather than recording the block number and the step number in the trace log. It can be suppressed.

In the above embodiment, an example of using a numerical value as an index has been described, but the present invention is not limited to this. For example, as shown in FIG. 10, the index may include numbers and letters. In the illustrated example, the index includes a block number and a step number, for example "B02S00" indicates step 0 of block 2.

In the embodiment, the example in which the PLC 100 assigns the index to each instruction has been described. For example, the development tool 500 assigns the index to each instruction and creates, for example, the data of the index table 1401 as shown in FIG. , The created data may be transmitted to the PLC 100.

In the embodiment, the function of the trace log storage unit 160 has been described as an example realized by the volatile memory 12, but the present invention is not limited to this. The function of the trace log storage unit 160 may be realized by a non-volatile memory. As the non-volatile memory, for example, a flash memory such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) memory card can be used.

In the embodiment, an example has been described in which the firmware includes a function of executing the preprocessing necessary for executing the trace and a function of tracing the execution of the step of the control program, but the present invention is not limited to this. For example, the OS (Operating System) may have these functions. Alternatively, the non-volatile memory 11 of the PLC 100 stores a program that allows the MPU 15 to execute the preprocessing necessary for executing the trace, and a program that allows the MPU 15 to realize the function of tracing the execution of the steps of the control program. It may have been done. In this case, by executing these programs, the MPU 15 realizes a function of executing the preprocessing necessary for executing the trace and a function of tracing the execution of the steps of the control program. Alternatively, the MPU 15 may realize these functions by executing a program stored in another computer connected via the network.

As a recording medium for recording a program that realizes the above-mentioned functions of the PLC 100, a computer-readable recording medium including a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, a semiconductor memory, and a magnetic tape can be used.

Further, the means for realizing the functions of the PLC 100 is not limited to software, and a part or all thereof may be realized by dedicated hardware. For example, as dedicated hardware, a circuit typified by FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit) may be used.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope. Moreover, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is indicated not by the embodiment but by the claims. And various modifications made within the scope of the claims and within the equivalent meaning of the invention are considered to be within the scope of the present invention.

B1, B2 Scroll bar, 11 Non-volatile memory, 12 Volatile memory, 13 I / O interface, 14,54 connection interface, 15,140 MPU, 19,59 bus, 51 memory, 52 input device, 53 display device, 55 CPU , 100 Programmable Logic Controller (PLC), 110 Program Storage, 111 User Program, 120 Program Execution, 130 Trace Preprocessing, 140 Index Information Storage, 150 Trace Execution, 160 Trace Log Storage, 500 Development Tools, 510 Trace execution instruction unit, 511 log display program, 520 trace log reading unit, 530 display unit, 701,702 connection cable, 801 detector, 802 controlled device, 1401,1402 index table

Claims (8)

Built using the sequential function chart is a programming language for the programmable logic controller, seen including a plurality of blocks having the steps describing the processing of the programmable logic controller performs, concurrently the step across the block Execution means to repeatedly execute the program to be executed
Prior to the execution of the program by the execution means , step information that is information that uniquely identifies the step in the program is generated, and the generated step information is assigned to each of the steps.
While the execution means is executing the program, as a trace log indicating the execution route of the step, the step information that identifies the executed step is the number of times the execution of the program is repeated. It is equipped with a log recording means that stores in the storage unit in association with the number .
At the time of creating the program, block identification information for identifying the block is assigned to each block, and in-block step identification information for identifying the step in the block is assigned to each step, and each step is assigned. The step information assigned to is different from the in-block step identification information assigned to the step.
The same step information is assigned by the allocation means, and in-block step identification information unique to each block to which the step belongs is assigned to the steps executed in parallel across the blocks.
Programmable logic controller. Further provided with a step information storage means for storing the step information,
The assignment means are each the step assigns a unique value that can uniquely identify the step in said program, said a unique value, and the block identification information, wherein the block Uchisu Te' flop It generates step information including identification information and stores the generated step information in the step information storage means,
The programmable logic controller according to claim 1. Said assigning means, said execution means preceding the execution of the program, stores the step information raw form has the step information storage means,
The programmable logic controller according to claim 2. The allocation means generates the step information when the programmable logic controller is powered on and the programmable logic controller executes the initial processing.
The programmable logic controller according to claim 1 or 3. A reading means for reading the trace log from the storage unit of the programmable logic controller according to any one of claims 2 to 4 and reading the step information from the step information storage means.
A display means for displaying the step specified from the step information included in the trace log in association with the number of execution cycles included in the trace log.
A computer equipped with. The display means
An image showing the number of execution cycles in which the step has been executed is displayed in association with the step number representing the step.
The computer according to claim 5. Built using the sequential function chart is a programming language for the programmable logic controller, seen including a plurality of blocks having the steps describing the processing of the programmable logic controller performs, concurrently the step across the block the method comprising the programmable logic controller, prior to executing the program, uniquely step information is a specific information over the step, assigning to each of said step of repeatedly executing a program to be executed by,
While the programmable logic controller is executing the program, the step information for identifying the executed step is accumulated in association with the number of execution cycles which is the number of times the execution of the program is repeated. only including,
At the time of creating the program, block identification information for identifying the block is assigned to each block, and in-block step identification information for identifying the step in the block is assigned to each step, and each step is assigned. The step information assigned to is different from the in-block step identification information assigned to the step.
The same step information is assigned, and the step identification information in the block unique to each block to which the step belongs is assigned to the steps executed in parallel across the blocks.
Method. Built using the sequential function chart is a programming language for the programmable logic controller, seen including a plurality of blocks having the steps describing the processing of the programmable logic controller performs, concurrently the step across the block In a programmable logic controller that repeatedly executes a program that is executed
Prior to executing the program, step information, which is information that uniquely identifies the step, is assigned to each step .
While the program is being executed, the step information that identifies the executed step is accumulated in association with the number of execution cycles, which is the number of times the execution of the program is repeated .
At the time of creating the program, block identification information for identifying the block is assigned to each block, and in-block step identification information for identifying the step in the block is assigned to each step, and each step is assigned. The step information assigned to is different from the in-block step identification information assigned to the step.
The same step information is assigned, and the step identification information in the block unique to each block to which the step belongs is assigned to the steps executed in parallel across the blocks.
program.

Images