JP2008040995A - Programmable controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily change a program by simplifying the description of an SFC program. <P>SOLUTION: In the case of executing a step instruction, when a step shown by a step management table 13 is put in an active status, the management number and instance address of an action POU shown by an action management table 15 are identified, and the address of an action POU 30 to be executed from the target entry of a POU management table 20 is identified from the POU management number, and the action POU is executed. In the case of executing the transition instruction, the management number of the step instruction connected before the transition instruction shown by a transition management table 14 is referenced to identify the management number and instance address of the transition POU 40 when the step is put in an active status, and the address of the transition POU to be executed is identified from the target entry of the POU management table from the POU management number to execute the transition POU. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a programmable controller that executes an operation using the SFC (Sequential Function Chart) language defined in JISB3503 (IEC61131-3), and particularly relates to an SFC operation method corresponding to the PLCenpen-XML schema. It is.

  In addition to SFC, JIS B3503 includes text language IL (Instruction List) language, ST (Structured Text) language, graphic language LD (Ladder Diagram) language, and FBD (Function BIock Diagram). Languages other than SFC execute instructions in order from the beginning of the program, so that the same calculation method as that of a normal computer program is possible.

  However, in the SFC, the program that actually operates is only the activated STEP, and when the transition condition following the activated STEP is satisfied, the next STEP is activated and the original STEP becomes inactive. For example, when Step 2 is in an activated state in FIG. 3, Step 3 is activated when Step 2 (transition) 2 conditions are satisfied, and Step 2 is inactivated.

  As described above, it is difficult to express an SFC operation in a normal computer program language. In addition, it is difficult to realize the SFC calculation with the instructions (calculation instructions) of a normal programmable controller. Therefore, there is a programmable controller that is implemented by a general-purpose microcomputer without using an arithmetic LSI of a programmable controller for SFC calculation.

In addition, in the case where the SFC calculation is executed by an instruction possessed by the programmable controller, a method has been proposed in which the SFC program is divided into a transition group program, an action group program, and a link group program (for example, Patent Document 1). , See Patent Document 2).
JP-A-6-242810 JP-A-5-150814

  Although there is no provision in JISB3503, transitions and actions that are constituent elements of SFC are defined as POU (Program Organization Unit) in the PLCopy-XML schema.

  Conventional SFCs of programmable controllers do not define and use transitions and actions as POUs. In other words, if you want to use the same algorithm for transitions and actions, define a combination of the algorithm and data definition as POU, and use the POU as many times as an instance of the data area that stores the variable part. I couldn't use it. In other words, it was necessary to program the same algorithm with different transitions and actions.

  For example, assume that Step 2 and Step 3 can be programmed with the same algorithm action in FIG. If the action cannot be described as a POU, Step 2 and Step 3 actions Action 2 and Action 3 need to be described as completely different programs even though they are the same algorithm. That is, the program memory is consumed separately. The same applies to Tran2 and Tran3 if the transition condition algorithm is the same.

  Further, according to Patent Documents 1 and 2, transitions and actions cannot be defined as POUs. Programmable controller instructions describe the execution part of transitions and actions. According to this method, when changing a part of the transition group program or action group program, it is necessary to compile the entire SFC program. From this, it can be said that the structure is difficult to cope with online change of the SFC program.

  An object of the present invention is to provide a programmable controller in which the description of the SFC program is simplified and the program can be easily changed.

  The present invention for solving the above-described problems is characterized by the following configuration.

(1) A programmable controller that executes an operation by an SFC program described by a step instruction group, a transition instruction group, and a step transition instruction group,
An action POU composed of a variable definition part and a body part describing an operation instruction for the action of the step instruction;
A transition POU composed of a variable definition part and a body part describing an operation instruction;
A step management table in which the management number of the action of the step command group and the address of the instance area used by the step command are arranged in the order of the step management number;
A transition management table having the POU management number of the transition POU and the address of the instance area used by the transition and arranged in the order of the transition management number;
An action management table having a POU management number of the action POU and an address of an instance area used by the action and arranged in order of the action management number;
A POU management table in which the POU parameters are described for the transition POU and the action POU in the order of management numbers;
The execution of the step command determines whether or not the step indicated in the step management table is in an active state. If the step is active, the management number and instance address of the action POU indicated in the action management table are identified, and the POU is identified. Identify the address of the action POU to be executed from the target entry in the POU management table from the management number, and execute the action POU.
After execution of the step instruction, the execution of the transition instruction refers to the management number of the step instruction connected before the transition instruction indicated by the management number in the transition management table, and the step corresponding to the step management number It is determined whether or not the corresponding step is in an active state with reference to an entry in the management table. If the step command is in an active state, the management number and instance address of the transition POU indicated in the transition management table are identified, The address of the transition POU to be executed is identified from the target entry of the POU management table from the POU management number, and the transition POU is executed.
After completion of the transition instruction, the execution of the step transition instruction updates the step activation flag using the step transition calculation result established by the execution of the transition instruction.
It is characterized by that.

  (2) The transition POU and the action POU are placed outside the SFC program.

  (3) The step management table, transition management table, action management table, STEP instruction group, TRAN instruction group, and STEP transition instruction group are placed in the SFC program.

  As described above, according to the present invention, the description of the SFC program is simplified and the program can be easily changed. Specifically, the following effects can be obtained.

  (1) Since transitions and actions can be defined as POUs, transitions and actions of the same algorithm can be used in an SFC program any number of times simply by preparing an instance area.

  (2) A program compliant with the PLCOpen-XML format can be created.

  (3) By having a STEP instruction group in the SFC program and indicating the management number of the step management table in the operand of the STEP instruction, access to the step instance area and action instance area via the step management table The associated action POU can be executed.

  (4) By having a TRAN instruction group in the SFC program and indicating the management number of the transition management table in the operand of the TRAN instruction, it is possible to access the transition instance area and execute the associated transition POU via the transition management table. become.

  (5) By executing the transition POU and the action POU via the POU management table, the same management as other types of POUs can be performed.

  (6) By executing the management of the transition POU and the action POU via the transition management table and the action management table of the SFC program, the SFC program calculation can be performed under the management of only the SFC program.

  (7) Since the transition POU and the action POU are placed outside the SFC program, it is not necessary to recompile the SFC program even if the algorithm of the transition POU or the action POU is changed. Therefore, online change processing can be easily performed.

(Embodiment 1)
FIG. 1 is a configuration example of an SFC program showing this embodiment, and has the following features.

  (1) Actions and transitions can be defined as POUs.

  (2) A STEP command is prepared to call the action POU.

  (3) Prepare a TRAN command to call the transition POU.

  (4) A step management table is prepared for associating a STEP command with an action.

  (5) An action management table is prepared for managing the action POU.

  (6) Prepare a transition POU to manage the transition POU.

  (7) A POU management table for managing POUs is prepared.

  (8) Easy to respond to online change of SFC program.

  (9) Place a step management table, transition management table, action management table, STEP instruction group, TRAN instruction group, and STEP transition instruction group in the SFC program.

  (10) Place the transition POU and action POU outside the SFC program.

  In FIG. 1, the SFC program 10 includes the following elements.

  The header 11 shows various attribute information of the SFC program as a program instance. The variable definition 12 is an area for defining variables used by the SFC program, and the management instance and internal variables are stored in an instance area 50 described later.

  The step management table 13 is a STEP management table in which a management number is assigned to each step existing in the SFC program and arranged in the order of the management number. In this, the management number of the action related to the corresponding step and the address of the instance area used by that step are shown. The management number of the step management table 13 is indicated in the operand of the STEP instruction. There may be a plurality of actions related to one step. Also, a Boolean variable can be set directly instead of an action.

  The transition management table 14 is a transition management table in which management numbers are assigned to the respective transitions existing in the SFC program and are arranged in the order of the management numbers. This shows the POU management number of the corresponding transition POU and the address of the instance area used by the transition. The management number of the transition management table 14 is indicated in the operand of the TRAN instruction.

  The action management table 15 is an action management table in which management numbers are assigned to actions existing in the SFC program and arranged in the order of the management numbers. In this, the POU management number of the corresponding action POU and the address of the instance area used by the action are shown. The step management table 13 shows the management number of the action management table 15.

  The STEP instruction group 16 is an instruction group for executing STEP existing in the SFC program. The management number of the step management table 13 is shown in the operand of these STEP instructions. The active state of a step determines whether the associated action is performed.

  The TRAN instruction group 17 is an instruction group for executing a transition existing in the SFC program. In the operands of these TRAN instructions, the management number of the transition management table 14 is indicated. Whether or not to execute the transition operation is determined by the active state of the step connected to the host.

  The STEP transition instruction group 18 is a collection of LD instructions for deactivating the activated step and activating the next step when the step transition condition is satisfied according to the operation result of the TRAN instruction group. is there. By these operations, the step activation flag in the step instance is updated.

  In addition to the above SFC programs, a POU management table 20 is prepared. In this POU management table 20, management numbers are assigned to POUs registered in the programmable controller, and POU parameters are described in the order of the management numbers. In addition to transitions and actions, POU has types of functions, function blocks, and programs. The POU management table 20 manages these POUs as a whole. The action management table 15 and the transition management table 14 indicate the management number of the POU management table 20 and the address of the POU to be executed. An actual transition POU and action POU can be executed via the POU management table 20.

  Hereinafter, the calculation method of the SFC program will be described with reference to FIG. An action POU 30 and a transition POU 40 are prepared as program memories, and an instance area 50 for storing SFC instances is prepared as a data memory.

  (S1) When the SFC program is activated, the first instruction of the STEP instruction group 16 is executed. The operand of the STEP instruction indicates the management number of the step management table 13, and the target step management number is referred to.

  (S2) It is determined from X or T whether the step in which the address of the step instance area in which the step activation flag is stored indicating whether the step is in the active state is stored in the step management table 13 is active. To do.

  (S3) If the corresponding step activation flag is in the active state, the management number of the action management table 15 shown in the step management table 13 is referred to. Thus, the address of the target action POU can be identified. In one step, a plurality of action management numbers can be registered.

  (S4) The action management table 15 identifies the POU management number of the target action POU and the address of the action instance area.

  (S5) The purpose entry of the POU management table 20 is identified from the POU management number, and the address of the action POU to be executed is identified.

  (S6) The action POU 30 is activated with the address of the action instance area as a parameter, and executes an action calculation. The end of the action POU is a RET instruction, and the next STEP instruction is executed.

  Therefore, the execution of the step command determines whether or not the step indicated in the step management table is in the active state, and if it is in the active state, identifies the POU management number and the instance address of the action POU indicated in the action management table. The address of the action POU to be executed is identified from the target entry of the POU management table from the POU management number, and the action POU is executed.

  (S7) After executing the above STEP instruction, the TRAN instruction of the TRAN instruction group 17 is executed. The TRAN command operand indicates the management number of the transition management table 14 and refers to the target transition management data.

  (S8) The transition management table 14 shows the step management number of the step command connected before the TRAN command. With reference to the entry of the step management table 13 corresponding to the step management number, it is determined whether or not the corresponding step is in an active state.

  (S9) If the flag of the corresponding step instruction is active, the transition POU management number shown in the transition management table 14 is referred to. Thus, the address of the target POU management table 20 can be known. In addition, the transition management table 20 shows addresses of transition instance areas used in the transition calculation.

  (S10) The purpose entry of the POU management table 20 is known from the POU management number, and the address of the transition POU 40 to be executed is determined. The transition POU 40 is activated with the address of the transition instance area as a parameter, and performs a transition operation. The end of the transition POU is a RET instruction, and the next TRAN instruction is executed.

  Therefore, the execution of the transition instruction refers to the step management number of the step instruction connected before the transition instruction indicated by the management number of the transition management table, and the entry of the step management table corresponding to the step management number To determine whether or not the corresponding step is in an active state, and if the step command is in an active state, identify the management number and instance address of the transition POU indicated in the transition management table, and from the POU management number The address of the transition POU to be executed is identified from the target entry in the POU management table, and the transition POU is executed.

  (S11) When the TRAN instruction is completed, the STEP transition instruction group 18 is executed. The step activation flag is updated using the result of the step transition operation established by the TRAN instruction group.

(Embodiment 2)
In the first embodiment, a POU management table 20 that collectively manages all POUs is prepared separately. However, transitions and actions used in SFC programs are rarely used in other languages. In addition, transition POUs and action POUs created with a certain SFC program are rarely used with other SFC programs. Therefore, the PFC management table 20 for managing the transition POU and the action POU can be included in the SFC program 10. FIG. 2 is a configuration diagram thereof, and the PFC management table is included in the transition management table 14 and the action management table 15 in the SFC program 10A. This makes it possible to manage SFC and other languages separately.

The structural example of the SFC program which shows Embodiment 1 of this invention. The structural example of the SFC program which shows Embodiment 2 of this invention. Example of active / inactive SFC program. An example of the processing procedure of the SFC program.

Explanation of symbols

10 SFC program 20 POU management table 30 Action POU
40 Transition POU
50 SFC instance area 11 Header 12 Variable definition 13 Step management table 14 Transition management table 15 Action management table 16 STEP instruction group 17 TRAN instruction group 18 STEP transition instruction group

Claims (3)

A programmable controller that executes an operation by an SFC program described by a step instruction group, a transition instruction group, and a step transition instruction group,
An action POU composed of a variable definition part and a body part describing an operation instruction for the action of the step instruction;
A transition POU composed of a variable definition part and a body part describing an operation instruction;
A step management table in which the management number of the action of the step command group and the address of the instance area used by the step command are arranged in the order of the step management number;
A transition management table having the POU management number of the transition POU and the address of the instance area used by the transition and arranged in the order of the transition management number;
An action management table having a POU management number of the action POU and an address of an instance area used by the action and arranged in order of the action management number;
A POU management table in which the POU parameters are described for the transition POU and the action POU in the order of management numbers;
The execution of the step command determines whether or not the step indicated in the step management table is in an active state. If the step is active, the management number and instance address of the action POU indicated in the action management table are identified, and the POU is identified. Identify the address of the action POU to be executed from the target entry in the POU management table from the management number, and execute the action POU.
After execution of the step instruction, the execution of the transition instruction refers to the management number of the step instruction connected before the transition instruction indicated by the management number in the transition management table, and the step corresponding to the step management number It is determined whether or not the corresponding step is in an active state with reference to an entry in the management table. If the step command is in an active state, the management number and instance address of the transition POU indicated in the transition management table are identified, The address of the transition POU to be executed is identified from the target entry of the POU management table from the POU management number, and the transition POU is executed.
After completion of the transition instruction, the execution of the step transition instruction updates the step activation flag using the step transition calculation result established by the execution of the transition instruction.
A programmable controller characterized by that.   The programmable controller according to claim 1, wherein the transition POU and the action POU are placed outside the SFC program. The programmable controller according to claim 1 or 2, wherein the step management table, transition management table, action management table, STEP instruction group, TRAN instruction group, and STEP transition instruction group are placed in the SFC program.

Images