JP2581611B2 - Control method of programmable controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control method of a programmable controller for controlling a process.

[Conventional technology]

Conventionally, a programmable controller that controls a process operates by a ladder program. While control circuits composed of AND and OR logic elements are used to control power plants, wired logic sequence circuits composed of relays and timers use a circuit diagram of a relay or timer between control power supplies. It is also called a ladder circuit because it is connected vertically to give an image of a ladder (ladder) and is used for controlling industrial plants. The ladder program represents the operation sequence of the sequence control as a program of the programmable controller.

For the ladder program, a flowchart language program expressed by a new programming language flowchart language has been developed. The flowchart language program has the following features.

1) Since programming can be performed without changing the operation procedure of the machine to be controlled, the design time required for programming is short.

2) When performing a test run of the machine, the operation can be checked step by step in the program, and the operation is completed in a short time.

3) The steps of the running program can be recognized at a glance, and the ON / OFF at that time is also displayed, so that maintenance is easy.

4) Since the operation is displayed in the form of a flowchart, the contents of the operation can be easily understood, and even a person other than the program designer can easily modify or change the program.

A method of linking a conventional ladder program and a flowchart language program is described in Vol. 53 of Yaskawa Electric Technical Report.
As described in J. No. 203, pp. 133-140 (1989, NO.2), in the event of an abnormality, a flowchart-type language program which is an abnormality processing sequence (also referred to as a major failure process) from a ladder program as a main program. Had started.

[Problems to be solved by the invention]

In the above prior art, the main part of the control program of the process control controller is represented by a ladder program, and no consideration is given to the structuring of the program. For example, in a sequence operation, a relay number is a specific data address. In the numerical operation, the programming style was conscious of hardware such as register numbers. For this reason, the program's documentability was very low, and the work of developing, changing, and modifying the program was inefficient. Also, parallel work of program development is difficult, even if the program is completed, it is difficult to test the system until it is incorporated into the actual machine, it is difficult to disconnect when troubleshooting a problem that occurs during operation on the actual machine,
There was a problem of confidential leakage due to the fact that know-how for actual operation and know-how for production were mixed in the same program.

An object of the present invention is to improve the productivity and maintainability of control program development.

[Means for solving the problem]

The object is to provide a method of controlling a programmable controller that includes a ladder program and a flowchart language program, and controls a process by synchronizing through an intermediate register accessed from both. A forced jump function and a forced output interlock function are provided so that when switching from a ladder program to a flowchart language program, a forced jump is made to the same state as the operation state of the ladder program. When a failure command is input, the flow chart language program is forcibly jumped to the stop / major failure process, and only when a serious failure command of the flowchart language program is input, the forced output is performed within its effective range by using a conditional expression. The turns on and off Rokku is achieved by performing the stopping step and a major fault steps of the flowchart expression language program in the same step.

The above object is attained by displaying the linked process in the flowchart language program by separating the condition fulfillment from the condition failing, and blinking the corresponding address when the condition is not fulfilled.

[Action]

According to the above configuration, by providing the forced jump function and the forced output interlock function on the operation process flow of the flow chart language program, the operation state can be controlled by the flow chart language program, and the plant can be controlled according to the operating procedure. By inputting, a flowchart language program can be created, so that the productivity and maintainability of the control program can be improved.

Also, when the linked process is displayed in the flow chart language program, the condition is satisfied and the condition is not satisfied, and if the condition is not satisfied, the corresponding address is blinked.
The device for which control is not being performed can be immediately identified, and the maintainability can be improved.

〔Example〕

An embodiment of the present invention will be described taking control of a pump of water and sewage equipment as an example.

Pumps are installed at various places on the vast site of water and sewage equipment,
The pump is controlled by a local operation panel composed of wire logic nearby and a programmable controller mounted on the instrument panel of the central control room. Conventionally, pump operation / stop operation is performed only on the local operation panel, and after the operator operates the pump on the local operation panel, the control mode of the local operation panel is switched to the central operation room to traverse the vast site. Until returning to the central control room, the next operation could not be performed and there was a long blank time (time constant).

FIG. 1 shows a configuration of a control system and a control mode of the present embodiment. First, control devices will be described.

An operation switch 3 for switching between the center and the site as an operation switch, an operation switch 8 for operating and stopping the pump, and an operation switch for opening and closing the pump discharge valve are provided on the operation panel 3 near the pump as operation switches. 9. An operation switch 10 for operating / stopping the cooling water pump for cooling the bearing of the pump and an operation switch 11 for operating / stopping the lubricating oil pump for supplying the lubricating oil to the bearing of the pump are provided. Operation switching switch 4
Since the mechanism has an overlap mechanism between the site and the center, the control operation for operating the pump is maintained even if the control mode is switched from the site to the center.

The central operation room is provided with a controller 2 connected to the on-site operation panel 3 and a central operation desk 1 connected to the controller 2. The central operation desk 1 is provided with a push button switch 5 for switching between automatic operation and manual operation, a push button switch 6 for operating / stopping the pump, and a push button switch 7 for opening / closing the pump discharge valve. Then, DDC control is performed by the host computer. On the other hand, when the manual operation is selected, the operation of the push-button switch 6 and the push-button switch 7 allows the operation and stop of the pump and the opening and closing of the pump discharge valve. When each of the switches and switches is operated by the central operation desk 1, the contents are transmitted to the controller 2, and the control calculation is performed by a program expressed in a flowchart language and a ladder program in which sequence control is programmed.

FIG. 2 shows the configuration of the controller 2.
Since the controller 2 is a programmable controller, an operation unit 20 for performing a control operation and an input / output device 21 for inputting / outputting data between the central operation desk 1 and the on-site operation panel 3 are provided.
It has. The arithmetic unit 20 includes a flowchart language processor 22 for executing the flowchart language program, a ladder processor 23 for executing the ladder program, a memory 24 for storing the flowchart language program and the ladder program, and a synchronization of the flowchart language program and the ladder program. An intermediate register 26 for performing the operation, a competition circuit 25 for accessing the intermediate register 26, an I / O interface 27, and a data bus 28 are provided. The arithmetic unit 20 and the input / output device 21 are connected via an I / O interface 27.

FIG. 3 shows the basic structure of the program. Each device 3
Ladder program 35, 3 for controlling 6, 38, 40 respectively
7, 39, flowchart language program 30, each ladder program and flowchart language program 30
There is an intermediate register 31 that can be read from and written to. The ladder program 35 describes the control operation of the device 36, the ladder program 37 describes the control operation of the device 38, and the ladder program 39 describes the control operation of the device 40. The flowchart language program 30 describes the control operation of a plant that controls the entire devices 32, 33, and 34, which is a combination of the ladder program and the devices.

FIG. 4 illustrates the configuration of the intermediate register and the access from the flowchart language program and the ladder program described in FIG.

X is the externally mounted contact input from the device, Y is the externally mounted contact output to the device, R is the internal register, J is the transfer register that transmits data from the flowchart language program to the ladder program, and Q is the flowchart language from the ladder program. XW is an external input word register, and YW is an external output word register.

A common name such as X, Y, or R is input from the flowchart language program and the ladder program to this intermediate register.
It can be accessed by such means. The intermediate register shown in the figure is an example, and the present invention is not limited by its name, type, and number.

FIG. 5 shows the contents of a ladder program of a controller for switching the control mode and operating / stopping the pump.

In the case of the on-site operation, the operator goes to the site where the pump is located, switches the operation switching switch 4 of the on-site operation panel 3 to the on-site mode, issues an operation command with the operation switch 8, and the ladder program confirms the interlock and operates the pump. Issue a command.

In the case of the central operation room operation operation, the operator goes to the site where the pump is located, switches the operation switching switch 4 of the site operation panel 3 to the central mode, returns to the central operation room, and operates the push button switch 5 of the central operation desk 1. When the operation is switched to the manual operation and an operation command is issued by the push button switch 6, the ladder program confirms the interlock and issues a pump operation command. When the push button switch 5 is switched to automatic operation, the DDC control issues an operation command, and the ladder program confirms the interlock and issues a pump operation command.

In the case of a local stop operation, when the operator goes to the site where the pump is located, switches the operation switching switch 4 of the local operation panel 3 to the local mode and issues a stop command with the operation switch 8, the ladder program confirms the interlock, stops the pump. Issue a command.

In the case of the central operation room stop operation, the operator goes to the site where the pump is located, switches the operation switching switch 4 of the site operation panel 3 to the central mode, returns to the central operation room, and operates the push button switch 5 of the central operation desk 1. When the operation is switched to the manual operation and a stop command is issued by the push button switch 6, the ladder program confirms the interlock and issues a pump stop command. When the pushbutton switch 5 is switched to the automatic operation, the DDC control issues a stop command, the ladder program confirms the interlock, and issues a pump stop command.

The opening and closing / stopping of the discharge valve is also controlled by a ladder program similar to that of the pump.

FIG. 6 shows a basic configuration for synchronizing a flowchart language program and a ladder program using an intermediate register. In the ladder program, create a program including manual conditions and interlocks for each execution step number of the flowchart language program, and at this time, use the transfer register to match the automatic operation contact with J001 and the execution step number of the flowchart language program Make sure that the interlock ladder Y010 also matches.

On the other hand, the flow of the entire process at the time of the automatic operation is described in such a manner that the ladder program is started by the output of the flowchart type language program using the transfer register J001 in the flowchart type language program.

FIG. 7 shows an embodiment in which a forced jump function is provided in a configuration for synchronizing a flowchart type language program and a ladder program using an intermediate register.

First, in the ladder program, when the pump is started from the on-site operation panel 3 of the plant to be in an operation state, and the operation switching switch 4 of the on-site operation panel 3 is switched to the central mode, the forced jump is performed according to the start condition of the flowchart language program. Using the function, the execution step number R0 of the flowchart language program corresponding to R009 of the ladder program
At 09, the control is forcibly jumped to the operation state, and the control is continued by the flowchart language program. Similarly, a forced jump is made to the execution step number R00A of the flowchart language program corresponding to R00A of the ladder program.

By providing the forced jump function in the flow chart language program in this way, it is possible to continuously control the operation state of the device that has been turned on by the ladder program by the flow chart language program.

FIG. 8 shows an embodiment in which a forced jump function is provided in a configuration for synchronizing a flowchart language program and a ladder program using an intermediate register, and a stop command and a serious fault command are issued during the operation process.

In the normal operation process, when the starting condition is satisfied, an operation command is issued to the cooling water pump and the lubricating oil pump at the request of the pump operation, a pump operation command is issued under the conditions of the cooling water pump operation confirmation and the lubricating oil pump operation confirmation, and the pump operation is performed. Upon confirmation, the discharge valve is fully opened by the discharge valve open command, and the pump enters the operating state.

In the stop process, a pump closing command is issued in response to a request to stop the pump while the pump is operating.After confirming that the discharge valve is fully closed, a pump stop command is issued.After confirming that the pump has stopped, the cooling water pump and the lubricating oil pump are stopped. A command is issued, and it is confirmed that the cooling water pump and the lubricating oil pump are stopped, and the process ends.

Further, in the serious failure process, a discharge valve closing command and a pump stop command are simultaneously issued in the above operation process, and after confirming that the discharge valve is fully closed and the pump is stopped, a stop command is issued to the cooling water pump and the lubricating oil pump, and the cooling water pump is issued. After confirming that the lubricating oil pump has stopped, the process ends.

When a stop command during a running process and a serious failure command are input in the flowchart language program, control is transferred to the stop / major failure process of the flowchart language program by the forced jump function. Thereafter, the execution of each step of the stop / serious failure process is completed, and the operation process ends.

FIG. 9 shows another embodiment in which a forced interlock function is provided in a configuration for synchronizing a flow chart language program and a ladder program using an intermediate register, and a serious failure command is issued during an operation process.

By specifying a y-number ([interlock condition on], [interlock release on]) for those that are normally on / off by a conditional expression only when there is a serious failure command in the flowchart language program The output Y *** is forcibly turned on / off so that the stop process and the severe failure process can be performed simultaneously.

(1) As an effective range of the interlock conditional expression, the external output Y000 is turned on if the condition 1 is satisfied by the expression, and is turned off if the condition 1 is not satisfied, and proceeds to the next step.
After the execution of the expression, the conditional expression 1 is valid up to the condition release expression, and the range of is referred to as the effective range of the condition 1. When the condition is not satisfied within the effective range of the condition 1, the external output is turned off, and when the condition is satisfied again, the external output is turned on.

(2) When controlling multiple points under the same interlock condition,
When the conditional expression 4 is satisfied in the expressions, the conditional expression is valid between the expressions and the expression, and Y020 is turned on. If the condition is not satisfied between the equations (1) to (4), Y020 is turned off, and if the condition is satisfied again, Y020 is turned on. After the expression, the conditional expression has no effect, and if Y020 is on, it will be on as it is. If the condition is already satisfied by the expression, the conditional expression is valid even between the expressions, and Y020 is turned on and Y021 of the expression is also turned off. If the conditional expression is not satisfied among the expressions, Y020 turns off and Y021 turns on. After the expression, the conditional expression has no effect. If Y020 is on, it will be on as it is, and if Y021 is also off, it will be off as it is.

(3) The movement of the plurality of interlock conditions is as follows. If the conditional expression is satisfied, the expression turns on Y000, the expression turns on Y001, the expression turns off Y002, and the setting expression is There is no output on / off because there is no output. The effective range of the interlock operation is conditional expression 1, or expression (1), expression (2), and expression (3).

FIG. 10 shows a monitor function on the process flow of the flowchart language program. The contents of the flowchart language program are displayed on the CTR screen during execution. The monitor functions are broadly classified into two types. One is a condition satisfaction function and the other is a condition failure function. If the condition is not met, the corresponding address on the CRT screen, that is, the hatched portion in the figure blinks, and The doll moves so that you can recognize which process is not executed because of the failure.

〔The invention's effect〕

According to the present invention, by providing a forced jump function and a forced interlock function in the flowchart language program, after the device is started on the local operation panel, the linked process of the flowchart language program is forcibly jumped to the operation state. Thereafter, control can be performed by a flow chart language program, and an effect of improving programming productivity and maintainability can be obtained by a flow chart language program capable of programming the operation procedure of the device as it is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control system according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a controller shown in FIG. 1, and FIG. 3 is a block diagram of a controller shown in FIG. FIG. 4 is a block diagram showing the basic configuration of the program, FIG. 4 is a block diagram showing the configuration of the intermediate register described in FIG. 3, and FIG. 5 is a description showing the contents of the ladder program of the controller according to the embodiment of the present invention. FIG. 6, FIG. 6 is an explanatory diagram for explaining the synchronization between the flowchart language program and the ladder program according to the embodiment of the present invention, and FIG. 7 is a flowchart language program provided with a forced jump function according to the embodiment of the present invention. FIG. 8 is an explanatory diagram for explaining the synchronization between a ladder program and a ladder program. Illustration of arm, FIG. 9 is an explanatory diagram for explaining the effective range of the forced interlock function provided in the flow chart expression language program according to an embodiment of the present invention, the 10
FIG. 5 is an explanatory diagram showing a monitor function on a process flow of a flowchart language program according to the embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Central operation desk, 2 ... Controller, 3 ... Field operation panel, 4 ... Operation switching switch, 5 ... Push button switch, 6 ... Push button switch, 7 ... Push button switch, 8 ... Operation switch, 9 ... Operation Switch, 10… Operation switch, 11… Operation switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yomasa Midai 5-2-1 Omika-cho, Hitachi, Ibaraki Pref. No. 1 Hitachi, Ltd. Omika Sakiba (56) References JP-A-60-262204 (JP, A) JP-A-1-209503 (JP, A)

Claims (2)

(57) [Claims] 1. A method for controlling a programmable controller, comprising a ladder program and a flowchart language program, and controlling a process by synchronizing through an intermediate register accessed from both, wherein an operation process flow of the flowchart language program is provided. A forced jump function and a forced output interlock function are provided above, and when the ladder program is switched to the flowchart language program, a forced jump is performed to the same state as the operation state of the ladder program, and the operation is performed by the flowchart language program. When a stop command and a serious failure command are input during the process, the flow chart language program is forcibly jumped to a stop / major failure process, and only when a serious failure command of the flowchart language program is input, a conditional expression is used. Control method for a programmable controller which turns on and off the forced output interlock within the scope of and performing a stop process and major fault steps of the flowchart formula language program in the same process with. 2. The method according to claim 1, wherein when the interlocking process is displayed in the flowchart language program, the condition is satisfied and the condition is not satisfied, and if the condition is not satisfied, the corresponding address is blinked and displayed. Control method of programmable controller.