JPH1091213A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the replacement of intelligent modules with no interruption of the system operation by initializing a dual port memory and also setting the module installation information for every scanning. SOLUTION: When an intelligent module is installed (S4), it's confirmed whether the installation information on the module is set (S5). If the installation information is set, the module service is given to the intelligent module (S8). If the installation information is not set (S5), the dual port memory of the intelligent module is initialized (S6) and the module installation information is set (S7). Then the module service is given to the intelligent module to which the installation information is set (S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller having a plurality of intelligent modules each having a CPU and a dual-port memory, and more particularly to a programmable controller which automatically recovers its operation when an intelligent module is hot-swapped. It is.

[0002]

2. Description of the Related Art A programmable controller is used as a control device of a system such as FA equipment and is constituted by a plurality of modules having predetermined functions. Each module is used by being inserted into a slot provided in the mount base corresponding to the location indicating the insertion position, and generally protects internal electronic circuits when the module is inserted or removed while the power is on. A hot-swap circuit is provided. FIG. 2 is a block diagram showing a configuration of the programmable controller. In FIG. 2, a programmable controller supplies drive power to a control module 1 that controls the system according to a control program, a plurality of input modules 2 to which contact signals such as limit switches are input, and drive sources such as solenoids and valves. It comprises a plurality of output modules 3 to be supplied, and a plurality of intelligent modules 4 having a CPU 41 and a dual port memory 42.

Each of these modules is inserted at an arbitrary location in the mount base, and is connected by a transmission line 5 for exchanging data with each other. The intelligent module 4 includes, for example, a communication module and the like, and is appropriately selected and used according to the specifications of the system. The control module 1 includes a main storage device 12 that stores a system control program, a CPU 11 that performs processing according to the control program, and a sub-storage device 13 that is used when the CPU 11 performs processing. The CPU 11 of the control module 1 performs the processing in the order of the addresses of the main storage device 12 in which the control program is stored, and returns to the first address when the processing of the final address is completed, and executes the same processing again. The control module 1 constantly repeats such processing while the programmable controller is operating. This one round of processing from the first address to the last address is called one scan.

In order to exchange data between the intelligent module 4 and the control module 1, it is necessary to initialize the dual port memory 42 of the intelligent module 4 in advance. The control module 1 initializes the dual port memory 42 of each intelligent module 4 when the power of the programmable controller is turned on, creates module installation information indicating that data can be exchanged with the intelligent module 4, and creates a secondary installation. It is stored in the storage device 13 (hereinafter, referred to as setting of module installation information). Then, in the processing for each scan, data is exchanged with the intelligent module 4 in which module installation information is set (hereinafter, referred to as module service).

[0005] As described above, the intelligent module 4 capable of performing the module service and its location are specified by the module installation information, and the module service is performed on the intelligent module 4. The intelligent module 4 operates with a predetermined function by using data sent from the control module 1. Next, a processing procedure when a control module performs a module service in a conventional programmable controller will be described with reference to FIG. FIG. 3 is a flowchart showing a processing procedure when a control module of a conventional programmable controller performs a module service. In FIG. 3, first, the processing at the time of power-on of the programmable controller will be described.

As shown in FIG. 3, the control module 1
First, an initialization process of an I / F (interface) unit of each module is performed, and it is confirmed whether or not each of the intelligent modules 4 is located at an arbitrary location (step S11). In order to confirm whether or not there is an intelligent module 4, for example, a flag indicating that the intelligent module 4 is present may be transmitted from each intelligent module 4. Alternatively, the inserted intelligent module 4 may be detected using a limit switch or the like. If there are intelligent modules 4 in step S11, the dual port memories 42 of those intelligent modules 4 are initialized (step S12), and module installation information is set (step S13). If there is no intelligent module 4 in step S11, the process proceeds to steps S14 to S17 described below without performing the processes in steps S12 and S13.

The processes in steps S11 to S13 are performed only once when the power of the programmable controller is turned on. Next, processing for each scan will be described. The control module 1 first checks whether or not the intelligent module 4 is present at any of the locations (step S14). Step S1
4, if there is an intelligent module 4, it is checked whether module installation information of the intelligent module 4 has been set (step S).
15). If module installation information is set, module service is performed for the intelligent module 4 (step S16).

If there is no intelligent module 4 in step S14, the module installation information set corresponding to the location is cleared (step S17). Then, returning to step S14, the processing up to step S17 is repeated for other locations, and the same processing is performed for all the locations where the intelligent module 4 is inserted.

[0009]

However, in the conventional programmable controller as described above, once the intelligent module is removed, the dual port memory is not initialized even if the intelligent module is inserted again. There was a problem that the module service of the intelligent module could not be performed. Therefore, when replacing an abnormal module as in a maintenance service, it is necessary to once turn off the power of the programmable controller and reset the CPU of the control module. The present invention has been made to solve the above-described problems of the conventional technology, and provides a programmable controller that automatically returns module service even when an intelligent module is replaced while power is on. The purpose is to:

[0010]

In order to achieve the above object, a programmable controller according to the present invention has a plurality of intelligent modules having a CPU and a dual port memory, and controls the operation of the system according to a control program. In each of the scan processes, if the intelligent module is located at an arbitrary insertion position and there is module installation information indicating that data can be exchanged with the intelligent module, the intelligent module operates. If the intelligent module is installed at an arbitrary insertion position and the module installation information of the intelligent module does not exist, the intelligent module After the initialization of the dual port memory of the module, the module installation information is created and stored in the internal memory, the module service is executed, and if the intelligent module is not at an arbitrary insertion position, the A control module for erasing the module installation information created corresponding to the insertion position is provided.

At this time, when the power is turned on, the control module initializes a dual port memory of the intelligent module inserted into an arbitrary position, and installs module installation information of the intelligent module. May be created and stored in the internal memory. In the programmable controller configured as described above, when the intelligent module is at an arbitrary insertion position and there is no module installation information of the intelligent module, the control module initializes the dual port memory of the intelligent module. After the module installation information is created and stored in the internal memory, the module service is executed.

Since such processing is performed for each scan, even if an intelligent module is inserted while the power is turned on, the control module can provide module services to the intelligent module.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. The programmable controller of the present invention includes:
The processing procedure for performing the module service of the intelligent module is different from the conventional one. The configuration of the device is the same as that of the conventional device, and the description is omitted. FIG. 1 is a flowchart showing a processing procedure when the control module of the programmable controller of the present invention performs a module service. In FIG. 1, first, a process at the time of power-on of the programmable controller will be described. As shown in FIG. 1, the control module first performs an initialization process of an I / F (interface) unit of each module, and confirms whether an intelligent module is present at an arbitrary location (step S1).

If there are intelligent modules in step S1, the dual port memories of those intelligent modules are initialized (step S2), and module installation information is set (step S3). If there is no intelligent module in step S1, steps S4 to S4 described below are performed without performing the processing in steps S2 and S3.
Proceed to step S9. The processes in steps S1 to S3 are performed only once when the power of the programmable controller is turned on. Next, processing for each scan will be described. The control module first checks whether or not there is an intelligent module for any of the locations (step S4).

If there is an intelligent module in step S4, it is checked whether module installation information of the intelligent module is set (step S5). If module installation information has been set, module service is performed for the intelligent module (step S8). If the module installation information has not been set in step S5, the dual port memory of the intelligent module is initialized (step S6), and the module installation information is set (step S7). Then, a module service is performed for the intelligent module for which the module installation information has been set (step S8).

If there is no intelligent module in step S4, the module installation information set corresponding to the location is cleared (step S9). Then, returning to step S4, the processing up to step S9 is repeated for other locations, and the same processing is performed for all the locations where the intelligent module is inserted. By performing such processing, the initialization of the dual port memory and the setting of the module installation information are performed for each scan, so that even if the intelligent module is inserted while the power is on, the control module is Module services can be provided for modules. Therefore, it is not necessary to turn off the power of the programmable controller when replacing the intelligent module, so that the intelligent module can be replaced without interrupting the system.

Further, a newly required intelligent module can be added to the system while the power is on. In the above description, an example is shown in which the initialization of the dual port memory and the setting of the module installation information are performed at the time of power-on and for each scan process. However, the effects of the present invention can be obtained only by initializing the dual port memory and setting the module installation information for each scan process. When the initialization of the dual port memory and the setting of the module installation information are performed also at the time of power-on as in this example, since these processes are performed collectively at the time of power-on, the number of steps in the scanning process is reduced. This has the effect that the processing of the entire control program is executed faster.

[0018]

Since the present invention is configured as described above, the following effects can be obtained. According to the first aspect, it is not necessary to turn off the power of the programmable controller when replacing the intelligent module, and the intelligent module can be replaced without interrupting the system. In addition, a newly required intelligent module can be added to the system while the power is on. According to the second aspect, the number of steps in the scanning process is reduced, so that the entire control program is executed more quickly.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a processing procedure when a control module of a programmable controller of the present invention performs a module service.

FIG. 2 is a block diagram illustrating a configuration of a programmable controller.

FIG. 3 is a flowchart showing a processing procedure when a control module of a conventional programmable controller performs a module service.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control module 2 Input module 3 Output module 4 Intelligent module 5 Transmission line 11, 41 CPU 12 Main storage device 13 Secondary storage device 42 Dual port memory

Claims (2)

[Claims] 1. A programmable controller having a plurality of intelligent modules each having a CPU and a dual port memory and controlling the operation of a system according to a control program, wherein the intelligent module is located at an arbitrary insertion position for each scan process. If there is module installation information indicating that data can be exchanged with the intelligent module, module services necessary for the operation of the intelligent module are executed, and the intelligent module is installed at an arbitrary insertion position. If there is a module and the module installation information of the intelligent module does not exist, the dual port memory of the intelligent module is initialized, and the module installation is performed. After the information is created and stored in the internal memory, the module service is executed. If the intelligent module is not located at an arbitrary insertion position, the module installation information created corresponding to the insertion position is deleted. A programmable controller comprising a control module. 2. The programmable controller according to claim 1, wherein the control module initializes a dual port memory of the intelligent module inserted in an arbitrary position when the power is turned on. A programmable controller for generating module installation information of the intelligent module and storing the module installation information in an internal memory.