JP2003122405A - Programmable logic controller, method for confirming operation of ladder sequence program thereof, and debugging tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To debug a ladder sequence program even while the subject of control is being controlled. SOLUTION: A programmable logic controller 101 which controls the subject of control by repeatedly running the ladder sequence program 102 at fixed intervals according to signals inputted from the subject of control is provided with a ladder action result transmission program 105 which outputs the result of ladder action to the outside each time one sequence cycle of the ladder sequence program ends. Also a debugging tool 106 is provided with a storage device 111 which receives and stores the results of ladder action externally outputted from the programmable logic controller 101, and a display means 110 for displaying the results of ladder action read from the storage device 111. Thus, detailed data can be monitored off-line even while the sequence is being run.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable logic controller for automatically controlling a controlled object such as a plant, a ladder sequence program operation confirmation method and a debug tool, and particularly, an operation confirmation without stopping the sequence when confirming the operation. PROGRAMMING LOGIC CONTROLLER AND OPERATION CONFIRMING METHOD FOR ladder sequence program and debugging tool.

[0002]

2. Description of the Related Art A ladder sequence program is debugged by turning on / off an input / output device of a programmable logic controller and an internal work device, and checking the operation of a data value. The conventional ladder sequence program debugging is performed by actually operating the ladder sequence program continuously, and the monitor device reads the operation result of the ladder sequence program at regular intervals and displays it on the display screen.

FIG. 8 is an explanatory view of essential parts of a conventional programmable logic controller 101 and a monitor device which is a debugging tool for a ladder sequence program thereof.
The ladder sequence program 102 in the programmable logic controller 101 is an input / output device 103.
The internal data is updated by referring to the internal work memory 104. The operation result monitor unit 107 of the monitor device 106 such as a personal computer transmits the operation result to the operation result transmission unit 105 of the programmable logic controller 101 in a predetermined cycle (in order to confirm the operation result of the ladder sequence program 102). For example, every 1 s cycle).

The operation result transmitter 105 in the programmable logic controller 101 which receives the transmission request is
Input / output device 1 of ladder sequence program 102
An on / off state such as 03 and the contents of the internal work memory 104 are transmitted to the operation result monitor unit 107 of the monitor device 106.

Programmable logic controller 10
1 executes the ladder sequence program in a predetermined cycle (for example, 200 ms cycle) that is not synchronized with the transmission request cycle from the monitor device 106, and therefore the operation result transmission unit 105 determines that the ladder sequence program execution cycle Are activated by operation result transmission commands from the monitor device 106 at different timings.

The operation result monitor unit 10 of the monitor device 106
7 is the operation result 1 of the received ladder sequence program
08 is displayed on the CRT 110 by the CRT control unit 109 at every CRT display update cycle, and by checking this display, the on / off state of the input / output device of the ladder sequence program 102 and the internal work device and the operation of the data value are confirmed. It becomes possible.

As described above, according to the conventional technique, the operation of the ladder sequence program is confirmed by the monitor device reading the operation result at a constant cycle on the screen. However, since the reading cycle of the monitor device is not synchronized with the operation timing of the ladder sequence, it is impossible to accurately confirm the on / off of the input device, output device, and internal work device and the fluctuation of the data value for each ladder sequence cycle. There's a problem.

For example, consider the case where piston control is performed by a ladder sequence program as shown in FIG.
This control is a sequence control in which when the piston moves from the C end to the A end, the A end is returned to the C end, and when the piston stops from the C end to the B end, the B end is returned to the C end (120 to 1).
23). The ladder sequence program outputs a movement command to the C end when the piston position reaches the A end or the B end, but the piston position A end input device (X030) or the piston position B end input device (X040) is turned on.
(In this FIG. 9, the ON state is indicated by ● and the OFF state is indicated by ◯.) Only during one or two ladder sequence cycles (in the above example, between 200 ms and 400 ms).

Therefore, the CRT screen 16 of the CRT 110 is
At 0, even if the A end input device (X030) or the piston position B end input device (X040) is turned on, as long as the reading cycle of the monitor device does not overlap,
It is not displayed in the ON state (●) and is displayed as OFF (○), and the movement of the actual plant cannot be confirmed. In particular, when the piston stops due to a problem between the A end and the C end, it cannot be identified whether it stopped during the movement from the A end to the C end or during the movement from the B end to the C end, It will take time to analyze the cause of the failure.

Therefore, for example, Japanese Patent Laid-Open No. 11-16740.
In the conventional technique described in Japanese Patent Publication No. 4, a program, an operation amount, and a control amount are stored in an internal memory for each predetermined operation unit, and when a trouble occurs, the stored contents of the internal memory are read out and associated with the program. I try to troubleshoot by going back and forth in time.

Further, in the prior art disclosed in Japanese Patent Laid-Open No. 7-114404, the execution start position and the execution stop condition in the program are designated so that the execution state when the execution stop condition is satisfied and the program is stopped. Is displayed on the monitor screen so that the actual operating status of the non-control side can be confirmed.

[0012]

However, in the prior art described in Japanese Patent Laid-Open No. 11-167404, the contents of the built-in memory of the programmable logic controller must be read out and displayed on the monitor device when a trouble occurs. However, there is a problem that the program cannot be verified during the control of the actual plant.

Further, the prior art disclosed in Japanese Patent Laid-Open No. 7-114404 is intended for a ladder sequence program simulation test.
Since the operation of the ladder sequence program must be stopped on the way, there is a problem that the operation of the ladder sequence program cannot be confirmed during control of the actual plant.

An object of the present invention is to confirm the operation of a ladder sequence program for each ladder sequence cycle during simulation test and actual plant test.
(EN) Provided are a programmable logic controller capable of performing verification without stopping a sequence even during execution of the sequence, a ladder sequence program operation confirmation method thereof, and a debug tool.

[0015]

In the programmable logic controller that controls a control target by repeatedly executing a ladder sequence program at a predetermined cycle based on an input signal from the control target, one sequence of the ladder sequence program is achieved. This is achieved by providing a means for externally outputting the ladder operation result each time the cycle ends.

[0016] The above-mentioned object is a ladder sequence program operation confirmation method of a programmable logic controller for controlling a control target by repeatedly executing a ladder sequence program at a predetermined cycle based on an input signal from the control target. This is achieved by receiving the ladder operation result externally output from the programmable logic controller at each end of the sequence cycle, storing it in a storage device, and monitoring the ladder operation result to confirm the operation.

In the programmable logic controller for controlling the control target by repeatedly executing the ladder sequence program at a predetermined cycle based on the input signal from the control target, the ladder operation is performed every one sequence cycle of the ladder sequence program. This is achieved by providing means for outputting the result to the outside, a storage device for receiving and storing the ladder operation result output to the outside, and display means for displaying the ladder operation result read from the storage device. .

According to the present invention, with the above configuration, the operation result can be monitored off-line even during the control of the controlled object, and the data for each sequence cycle can be monitored. Can be verified.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a ladder sequence program debug tool according to an embodiment of the present invention. The ladder sequence program 102 in the programmable logic controller 101 is, for example, 200 ms
Input / output device 103 and internal work device 10 for each
4, the internal data is updated.

Further, in the programmable logic controller 101 according to the present embodiment, the ladder sequence program 102 is set at every end of one sequence cycle (200
every ms), a transmission command is issued to the program 15 to activate the operation result transmission program 105. The ladder operation result transmission program 105 that has received this transmission command is the input / output device 103 of the ladder sequence program 102.
And the contents of the internal work memory 104, that is, the ladder operation result is transmitted to the ladder operation result monitor program 107 of the monitor device 106.

The ladder operation result monitor program 107 that has received this transmission receives (2
The ladder sequence program operation result of every 00 ms) is stored in the ladder sequence program operation result file 11
Store in 1. When requested by the operator, the CRT control program 109 reads the ladder operation recording file 111 at any time and reproduces and displays the ladder operation recording data on the CRT 110. This reproduction display can be fast forwarded, rewound, slow reproduced, paused, etc. based on an instruction from the operator.

FIG. 2 is a flow chart showing a transmission procedure performed by the ladder operation result transmission program 105 which receives a transmission command from the ladder sequence program 102 shown in FIG. The ladder sequence program 102 sends a ladder end report to the ladder operation result transmission program 105 every time one sequence cycle ends. The ladder operation result transmission program 105 has this ladder end report, and the ladder operation result transmission management flag described later is ON.
At this time, the on / off state of the input / output device 103, which is the ladder operation result, the content of the internal work memory 104, and the data value are transmitted to the ladder operation result monitor unit 107 of the monitor device 106 (steps 130 to 13)
2).

FIG. 3 is an explanatory diagram for managing the necessity of transmission of the ladder operation result. The programmable logic controller 101 according to the present embodiment does not unconditionally transmit the ladder operation result to the monitor device 106 every sequence cycle, but when the operator inputs “transmission required” to the monitor device 106, 1 The ladder operation result is transmitted to the monitor device 106 every sequence cycle.

Therefore, the CRT 11 of the monitor device 106
The management condition of the necessity of transmission of the ladder operation result input by the operator from 0 is via the CRT control program 109,
It is transmitted to the programmable logic controller 101 from the ladder operation result transmission condition program 107a. Ladder operation result transmission condition program 102 that received this
“A” manages the necessity of transmitting the ladder operation result. That is, the ladder operation result transmission management flag is set to “ON” or “OFF” according to the management condition, as will be described later in detail.
To

FIG. 4 is a flow chart showing a processing procedure performed by the ladder operation result transmission condition program 107a shown in FIG. Ladder operation result transmission condition program 107
a determines whether or not the ladder operation result transmission automatic command is received from the CRT 110 of the monitor device 106 (step 140), and when the transmission automatic command is received, the ladder operation result transmission management mode of the ladder operation result management table is set. It is set to "automatic" (step 141). When the determination result of step 140 is negative, the routine proceeds to step 142, and it is determined whether the received command is a ladder operation result transmission manual command. When the determination result is negative, the process proceeds to step 144, and when the determination result is affirmative, the ladder operation result transmission management mode is set to "manual" in step 143, and then step 1
Proceed to 44.

In step 144, it is determined whether or not the ladder operation result transmission management mode is "manual". When this determination result is negative, the process proceeds to step 149 described later, and when the determination result is affirmative, it is then determined whether or not a ladder operation result transmission start command has been received from the monitor device 106. When the transmission start command is received, the process proceeds to step 146, and the ladder operation result transmission management flag of the ladder operation result management table is set to O.
Set to N. In the next step 147, the monitor device 106
It is further determined whether or not the ladder operation result transmission stop command is received, and when the stop command is received, the ladder operation result transmission management flag is turned off.

The ladder operation result transmission management mode is "automatic"
If so, the process proceeds from step 144 to step 149, and thereafter, steps 150 to 148 similar to steps 145 to 148 are performed.
In 153, “ON” or “OFF” of the ladder operation result transmission management flag is managed based on the ladder operation result transmission start / stop condition received from the monitor device 106.

For example, when the transmission of the ladder operation result is started when the valve is fully opened and the transmission of the ladder operation result is ended when the valve is completely closed, "valve fully open (device X010)" is set as the ladder operation result transmission start condition. , The ladder operation result transmission stop condition is “valve fully closed (device X01
1) ”will be set. In this case, referring to the input / output device 103, when the valve fully closed (device X011) is turned on, the ladder operation result transmission management flag is set to "OF".
F ”. Also, when the valve fully open (device X010) is turned on, the ladder operation result transmission management flag is "ON".
To be done.

Finally, in step 154, it is determined whether or not the communication with the monitor device is disconnected. If the communication is not disconnected, a return process is performed, and if the communication with the monitor device is abnormal and the communication is disconnected, , Ladder operation result transmission management flag is set to OF
After F (step 155), return processing is performed.

FIG. 5 shows the monitor device 1 when the ladder operation result transmission necessity management condition is set from the CRT 110 of FIG.
It is a figure which shows an example of the CRT screen in 06. Ladder operation result transmission management mode, CRT screen manual switch SW
3 and automatic switch SW4.

Further, when "manual" is selected, switching is performed by the ladder operation result transmission start command SW5 and the ladder operation result transmission stop command SW6 on the CRT screen. When "automatic" is selected, the ladder operation result transmission start / stop condition 7 is set on the CRT screen. For example, when starting with valve fully open and ending with valve fully closed, set "Valve fully open (input device X010)" as the ladder operation result transmission start condition 7 on this CRT screen, and ladder operation result transmission stop condition 8 Is set and input "valve fully closed (input device X011)".

The ladder operation result transmission management mode switching command, the ladder operation result transmission start condition and the stop condition input from the CRT screen are transmitted from the condition transmitting / receiving unit 112 of the ladder sequence program operation result of the monitor device 106 to the programmable logic controller 101. Sent to.

FIG. 6 is a configuration diagram of the ladder sequence program operation result file 111. The ladder sequence program operation result file 111 stores ON / OFF data of the input / output device, ON / OFF data of the internal work device, and the like for each sequence cycle from the start to the stop of transmission of the operation result.

FIG. 7 is a diagram showing an example in which the CRT screen 160 of the CRT 110 according to the present embodiment refers to the ladder operation result file 111 and bitwise displays the information of the input device for each ladder sequence cycle. . The display time and device name can be changed on this screen.

The display example of FIG. 7 is a sequence control table in which when the piston moves from the C end to the A end, the A end is returned to the C end, and when the piston stops from the C end to the B end, the B end is returned to the C end. It is an example (120-123) and is a figure corresponding to the prior art example of FIG. Since the ladder sequence program outputs a movement command to the C end when the piston position reaches the A end or the B end, the piston position A end input device (X0
30) Alternatively, the piston position B end input device (X0
40) is turned on, as described in FIG.
Only during 1-2 ladder sequence cycles from ms to 400 ms. Although such a phenomenon is unknown in the observation in the 1s cycle, since data is collected every sequence cycle as in the present embodiment, as shown in FIG. 7, the input device is in the ON state (● state). ) Is clearly revealed.

In this screen display, time-series information can be confirmed on the screen by scrolling the device information display in the direction of advancing the display time or in the past direction. Furthermore, if the display time is changed, the device information at the set display time is displayed.
By operating such a function, not only the phenomena can be confirmed in a time series, but also when the phenomenon actually occurred in the plant is to be reconfirmed, it is not necessary to perform a reproduction test.

[0038]

According to the present invention, the programmable controller can be used in the simulation test or the actual plant test even when the ladder operation result, for example, the ON / OFF of the input / output device and the internal work device and the data value change every ladder sequence cycle. The operation result for each ladder sequence cycle can be easily confirmed. In addition, even if it cannot be performed many times, such as the operation confirmation test during actual plant operation, the operation result for each sequence cycle is saved in a file, so the operation result file can be used for every sequence cycle. You can check the operation of.

[Brief description of drawings]

FIG. 1 is a block diagram of a ladder sequence program debug tool according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure of transmitting a ladder operation result according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of management of necessity of transmission of a ladder operation result according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a procedure for managing whether or not ladder operation result transmission is required by the ladder operation result transmission condition program according to the embodiment of the present invention.

FIG. 5 is a diagram showing a screen display example of a debug tool according to an embodiment of the present invention.

FIG. 6 is a diagram showing a configuration example of a ladder sequence program operation result file shown in FIG. 1.

FIG. 7 is a diagram showing an example in which bit information is displayed in time series on an input device for each ladder sequence cycle with reference to the ladder operation result file shown in FIG. 1;

FIG. 8 is a block diagram of a debug tool for confirming the operation of a conventional ladder sequence program.

FIG. 9 is a diagram showing a screen display example for confirming an operation result of a ladder sequence program in a conventional programmable logic controller.

[Explanation of symbols]

101 programmable logic controller 102 Ladder sequence program 103 I / O device 104 Internal work device 105 Ladder operation result transmission program 106 monitor device 107 Ladder operation result monitor program 109 CRT control program 110 CRT 111 Ladder sequence program operation result file

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masuda Adult             5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture             Inside the Hitachi Information Control System (72) Inventor Koichi Juichi             5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture             Information Control Systems Division, Hitachi, Ltd.             Within F-term (reference) 5H220 AA01 BB10 DD04 JJ12 JJ26                       JJ28 JJ53 JJ59 KK05 KK06                       KK08 LL06 MM07                 5H223 AA01 CC03 CC08 DD03 EE05                       EE06 EE19 FF05

Claims (4)

[Claims] 1. In a programmable logic controller that controls a control target by repeatedly executing a ladder sequence program at a predetermined cycle based on an input signal from the control target, a ladder operation result is displayed every one sequence cycle of the ladder sequence program. A programmable logic controller comprising means for outputting externally. 2. A ladder sequence program operation confirmation method of a programmable logic controller for controlling a control target by repeatedly executing a ladder sequence program at a predetermined cycle based on an input signal from the control target,
Each time a sequence cycle of the ladder sequence program is completed, a ladder operation result externally output from the programmable logic controller is received and stored in a storage device, and the ladder operation result is monitored to confirm the operation. A method for checking the operation of a ladder sequence program of a programmable logic controller. 3. A programmable logic controller for controlling a control target by repeatedly executing a ladder sequence program at a predetermined cycle based on an input signal from the control target, and displaying a ladder operation result every one sequence cycle of the ladder sequence program. A debugging tool comprising: means for externally outputting; a storage device for receiving and storing the ladder operation result externally output; and a display means for displaying the ladder operation result read from the storage device. 4. The debug tool according to claim 3, wherein the display unit synthesizes and displays the operation record for each of the sequence cycles.