JPH05224712A - Producing method of prom for programmable controller - Google Patents

Abstract

PURPOSE:To provide a producing method of PROM for PC(programmable con troller) in order to obtain the PC of a small capacity memory and to prevent the breakage of the PC contents even in an operating environment. CONSTITUTION:A normal user program is stored in a PROM together with an execution program obtained by converting the user program into the machine words. When the PROM is loaded into a PC and the sequence control is carried out, a CPU can directly carry out the execution program of machine words stored in the PROM. Therefore the operational processing is quickly performed. Then the execution program is stored in the PROM not in a PC memory and therefore the capacity of the PC memory can be reduced. Thus a user can use an expensive PC. Furthermore the user program and its execution program are written in the PROM for which the contents of these programs are not easily broken even in an inferior operating environment. In such a constitution, a PC performing a stable operation is provided for a user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a PROM for a programmable controller.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of a PROM writer. This PROM writer comprises a CPU 1, a memory 2 and a PROM interface circuit 3. The PROM interface circuit 3 is a circuit for writing to the PROM 4 or reading out the contents written in the PROM 4, and the memory 2 stores a user program read from the PROM 4 or a programmable controller (hereinafter referred to as PC) 5. It

FIG. 3 is a flow chart showing a conventional method for creating a PROM for a PC. First, PROM4 or P
The user program is read from C5 and stored in the memory 2. Next, the user program in the memory 2 is written in the unwritten PROM 4 newly installed in the PROM writer.

Conventionally, when creating a PROM for a PC,
As described above, the user program is written by the PROM writer, and when this PROM is mounted on the PC and used, there are the following problems. (1) When the PC executes the operation, it is necessary to convert the user program stored in the PROM into an execution program composed of a machine language that can be directly executed by the CPU and store it in the memory in the PC. Since this execution program generally has a capacity about three times as large as that of the user program, an extra storage memory is required, resulting in high cost. Further, this storage memory must be arranged on the substrate, and it may be difficult to provide the space for the substrate in a small-scale PC. (2) When used in a place where the operating environment is bad, the contents of the memory may change, and as a result, the contents of the execution program may be destroyed and the PC may become uncontrollable.

The present invention has been made in order to solve the above problems, and provides a method for realizing a PC having a small-capacity memory and a PC PROM whose contents are not easily destroyed even in an operating environment. The purpose is to do.

[0006]

Means and Actions for Solving the Problems P according to the present invention
To create a C PROM, write the PC user program in the PROM,
It is converted into an execution program composed of a machine language that can be directly executed by U and written in the PROM. P created in this way
When the ROM is attached to the PC and sequence control is executed,
The CPU of the PC can directly execute the machine language execution program written in the PROM, and the arithmetic processing can be speeded up. Further, since it is not necessary to store the machine language execution program in the memory in the PC, it is possible to contribute to downsizing of the PC. Further, by using the PROM, the program written therein is less likely to be destroyed even in a bad environment.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a programmable circuit diagram of an embodiment of the present invention.
It is a flow chart which shows a PROM creation method of a controller. First, the user program is read from the PROM 4 or PC 5 and stored in the memory 2 (S1).
Next, the user program in the memory 2 is stored in the PROM.
An unwritten PROM newly installed in the writer
Write to (S2). The above processing is the same as the processing in the flowchart of FIG.

Next, initialization is performed (S3). By this initial setting, the read address of the user program is set, and the PRO of the execution program in machine language to be created is set.
The setting of the write address to M and the like are set. After that, one instruction of the user program in the memory 2 is read (S4). After the reading, the program is analyzed (S5), an execution program in machine language that can be directly executed by the CPU of the PC used in combination with this PROM is created based on the instruction execution procedure, and written in the memory 2 (S6). Next, the machine language execution program in the memory 2 is written in the PROM 4 via the PROM interface circuit 3 (S7). Then, it is determined whether the processed instruction is an END instruction (program end instruction), and if it is not an END instruction, post-processing is performed (S
9) Update the read address of the user program and the write address of the PROM. Then, returning to the above processing (S4), the above processing is repeated until the END instruction is received (S8).

[0009]

As described above, according to the present invention, in addition to the normal user program, the execution program converted into a machine language is stored in the PROM.
When ROM is mounted on the PC and sequence control is performed, CP
Since the U can directly execute the machine language execution program stored in the PROM, the arithmetic processing can be performed quickly. Since the machine language execution program is stored in the PROM instead of the memory of the PC, a PC with a small capacity memory can be realized and an inexpensive PC can be provided to the user. In addition, even when used in a bad operating environment, the user program and its execution program are written in a PROM that is not easily damaged even in a bad operating environment, thus providing a user with a PC that operates stably. can do.

[Brief description of drawings]

FIG. 1 is a flowchart showing a PC PROM creating method according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a PROM writer.

FIG. 3 is a flowchart showing a conventional method for creating a PROM for PC.

Claims (1)

[Claims] 1. A PROM for a programmable controller, characterized in that a user program for a programmable controller is written in a PROM, and the user program is converted into an execution program consisting of a machine language that can be directly executed by a CPU and written in the PROM.
How to create.