JPH03268004A - Process controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a process control device that performs process control using a built-in microcomputer having process control program information in a ROM.

(Prior Art) Conventionally, process control program information and control parameters are generally stored in a ROM and installed in a control device.

When it becomes necessary to change the process control program, this ROM is replaced.

(Problems to be Solved by the Invention) However, in such conventional process control devices, when changing a program during the test stage of development, there are three steps: 1) modifying the program, 2) creating a ROM, 3) replacing the ROM, 4) Confirmation test: It was necessary to perform the following steps. Conventionally, in each of these steps, a lot of time is required for 2) ROM creation and 3) ROM replacement, resulting in poor work efficiency. In particular, regarding ROM replacement in 3), normally,
Inserting and removing the board from the device, ROM-I C from the board
There have been many problems in that the mechanical fatigue exerted on the board during insertion and removal operations can damage the board or accidentally damage other hardware. Furthermore, if the working environment is poor, the replacement work will take a lot of time, making changing the program very time-consuming.

The present invention was made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a process control device that can reduce the need for ROM replacement and also allows easy program changes in a place with a good working environment. do.

[Structure of the Invention] (Means for Solving the Problems) A process control device of the present invention includes a ROM that stores program information and control parameters, a serial transmission means,
A RAM into which control parameters inputted through the serial transmission means are written, and a reception flag which sets the reception flag to zero when the ROM is replaced and has a reception flag when the program information from the serial transmission means is written to the RAM. generating means, and when the reception flag generation means has no reception flag, executes process control based on the program information and control parameters stored in the ROM, and when the reception flag is present, the reception flag generation means executes process control based on the program information and control parameters stored in the ROM; and control means for executing process control based on control parameters stored in the RAM.

(Function) In the process control device of the present invention, the process control program is divided into a reception program that processes received data and a control program, and the control program stores control parameters that are likely to cause adjustment elements in both the ROM and RAM. Create it so that it can last.

The control program has a reception flag that indicates whether or not a control parameter has been received, and in the initial state or immediately after ROM replacement, the reception flag is set to zero to indicate that the control parameter has not been received. Then, when the receiving program receives a new control parameter through the serial transmission means, it sets the receiving flag to
Store the received parameters in RAM.

Therefore, when the control means performs process control, if the reception flag is absent, the process control is performed based on the control parameters of the ROM, and when the reception flag is present, the process control is performed based on the control parameters of the RAM.
The process is based on the control parameters of
Even if new process control parameters become necessary due to continued process control, the control program can be changed by writing to RAM via serial transmission means, and the ROM must be replaced one by one to accommodate new control. You can reduce the chances of this happening.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which a control device 1 that performs process control is equipped with a ROM 2 and a RAM 3 with a battery backup function. Control parameters used in the control program can also be stored on the side.

Reference numeral 4 denotes a reception flag generation unit which sets the reception flag to nothing in the initial state and sets the reception flag to existence when there is a write input of control parameters from the external serial transmission means 5, and is usually a part of the RAM 3. will be applied to this, but for convenience of explanation, it is depicted as a separate thing.

Reference numeral 5 denotes an IloIF, which is an interface that controls overall data input/output, such as input/output of process control signals, input/output of display data signals, and writing/input of control parameters.

A microprocessor (CPU) 6 performs process control arithmetic processing.

A key manual device 7 is connected to the process control device 1 by a transmission line 8 as an external serial transmission means. Further, process equipment 9 as a control target is connected.

Next, the operation of the above process control device will be explained.

As shown in the flowchart of FIG. 2, the process control device 1 executes a reception program A and a control program B.

In the initial state or in the initial state immediately after ROM replacement, the reception flag of the reception flag generation unit 4 is in the control parameter unreceived state and is null (step S1), and the process control program B is the control stored in the ROM 2. It is executed based on the parameters (step S2).

When changing the program, when the operator inputs the control parameters to be changed from the key manual device 7, the received program A is executed. If the changed parameters are received, the reception flag is set to "Yes" and the received changed parameters are written into the RAM 3 (steps 813 to 515).
.

In this way, when the control parameters are written into the RAM 3, the reception flag in step S1 is changed from "no" to "yes" when the control program B is executed. will be executed based on the control parameters (
Step S3) Once the control parameters are well established, R
A ROM is created in which the contents written in AM3 are written, and this is installed in ROM2 of the process control device 1. By exchanging this ROM2, the receiving program A
Step S11 becomes YES, and the reception flag of the reception flag generation unit 4 is set to nothing, making it an initial state (
Step 512).

Therefore, from now on, process control will be executed again based on the control parameters stored in ROM2 until new control parameters are written to RAM3 (steps Sl, S2). Instead of replacing the ROM with a new one every time a parameter changes and executing process control, the control parameters are written to RAM until the control parameters are established to a certain extent, and the control written to this RAM is By controlling the process based on parameters, the number of ROM replacements can be reduced, and the risk of damaging the board or other hardware during replacement can be reduced. Also, replacing the ROM is very time consuming, but since the control parameters can be easily input using the serial transmission means, program changes can be made easily.

FIG. 3 shows another embodiment of the present invention. In the case of a system in which process control is performed using a plurality of the same process control devices 1 in parallel, the present invention is applied to each process control device 1, Each process control device 1 is connected to a key human power device 7 as a serial transmission means via a serial transmission line 8.

By adopting a system with such a configuration, by inputting change data using one key manual device 7, the ROM of each process control device 1 can be replaced one by one.
The control parameters of each process control device 1 can be changed individually or regularly.

[Effects of the Invention] As described above, according to the present invention, the control parameters necessary for process control can be stored in the RAM as well as the ROM, the control parameters are written in the RAM by the serial transmission means, and the reception flag is set. By doing this, the process can be controlled based on the changed control parameters stored in the RAM, so there is no need to replace the ROM every time there is a change in the program, and the number of ROM replacements is reduced compared to conventional methods. The risk of damage to the board and hardware can be significantly reduced, and the work time required for ROM replacement work can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the above embodiment, and FIG. 3 is a block diagram of another embodiment of the invention. 1... Process control device 2... ROM3...R
AM 4... Reception flag generation unit 5...
input/output interface

Claims (1)

[Scope of Claims] A ROM for storing program information and control parameters, a serial transmission means, a RAM for writing control parameters inputted through the serial transmission means, a reception flag set to zero when the ROM is replaced, and a reception flag generation means that sets a reception flag when program information from the serial transmission means is written into the RAM; and program information stored in the ROM when the reception flag generation means sets the reception flag to null. and a control unit that executes process control based on the control parameter, and executes process control based on the control parameter stored in the RAM when the reception flag is set.