JPH04218807A - Programmable controller - Google Patents

Abstract

PURPOSE:To easily preserve or take out a variable in a program in the BASIC language in or from an external storage device in the command level and to preserve this variable in the external storage device even in the state that the BASIC program cannot be executed because of trouble of hardware. CONSTITUTION:A variable holding memory area is provided where a specific variable of variables used by the program in the BASIC language is stored in such mode that it is not initialized at the time of program execution, and the variable to be held is stored in the variable holding memory area and is held without being initialized at the time of program execution, and the variable in the variable holding memory area is preserved in the external storage device or the variable preserved in the external storage device is taken out to the variable holding memory area by a defined command.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller, and more particularly to a programmable controller having a user interface operated by a program written in BASIC language.

0002

[Prior Art] As a programmable controller, B
Some devices are known that have user interfaces that operate using programs written in ASIC language. In this programmable controller, when executing a program using the BASIC language, a variable memory area used for executing the program is secured, and the program is executed without being affected by the previous variable values stored in the variable memory area. In order to do so, the variable memory area is initialized prior to program execution.

0003

[Problem to be Solved by the Invention] The handling of variables in a program using the BASIC language used in a programmable controller is completed within the execution range of the program, but it is difficult to store variable data at a specific timing in an external storage device. When attempting to save variable data stored in an external storage device into a program for reuse, the user must create a special program for each process.

[0004] Furthermore, if a program for the above-mentioned processing is not prepared, if a hardware failure suddenly occurs in the system and the hardware has to be replaced, the variables become impossible to save and reuse.

The present invention was made by focusing on the above-mentioned problems in conventional programmable controllers, and allows variables in a program written in BASIC language to be easily stored in an external storage device at the command level. keep,
Alternatively, it is an object of the present invention to provide a programmable controller configured such that the variables can be retrieved from an external storage device and can be saved in the external storage device even under a condition where the BASIC program cannot be executed due to a hardware failure. The purpose is

[0006]

[Means for Solving the Problems] According to the present invention, in a programmable controller having a user interface operated by a program in the BASIC language, it is possible to specify among variables used in the program in the BASIC language. A variable holding memory area that stores variables in a manner that is not initialized during program execution, and a variable holding memory area that stores variables in the variable holding memory area in an external storage device by a defined command, and a variable that is saved in the external storage device. This is accomplished by a programmable controller configured to retrieve the variable into the variable holding memory area.

[0007]

[Operation] According to the above-mentioned structure, a specific variable among the variables used in a program written in the BASIC language, that is, a variable to be held, is stored in the variable holding memory area, and this variable is thereby initialized when the program is executed. Variables stored in the external storage device are stored (saved) in an external storage device by a defined command, and are retrieved (loaded) into the variable storage memory area by a defined command.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a programmable controller according to the present invention. This programmable controller includes a CPU section 1 as a PC main body, and a BAS
It has an IC language operation section 10.

The CPU unit 1 includes an MPU 2, a system ROM 3 storing a programmable controller system program, a RAM 4 storing a programmable controller user program, programmable controller variables, etc., an input/output interface 5, and an external storage device interface. 6. An external storage device 7 such as a memory card is connected to the external storage device interface 6.

[0011] The BASIC language operating unit 10 is an MPU 11
, a system ROM 12 storing a system program for executing programs in BASIC language, and R
It has an OM 13, a programmable controller interface 14, and an input/output interface 15,
It is connected to the CPU unit 1 through a programmable controller interface 14, and a CRT 16 and a keyboard 17 for inputting commands are connected to an input/output interface 15.

As shown in the figure, the ROM 13 of the BASIC language operating unit 10 stores general variables used for executing user programs in the BASIC language, in addition to a user program area and a work area that store user programs in the BASIC language. It has separate general variable areas and holding variable areas for storing specific variables. In this case, the general variable area is initialized before the execution of the user program in BASIC language, and the variables stored in the general variable area are automatically erased by the execution of the user program, but the retained variables The area is held without being initialized when a user program in BASIC language is executed, and the variables stored in this holding variable area are not erased by execution of a user program in BASIC language.

Saving of the variables in the retained variable area to the external storage device 7 is performed by keying in a predefined command such as "VSAVE" from the keyboard 17, and the above-mentioned retention of the variables stored in the external storage device 7 Extraction from the variable area is done using the predefined “VLOAD”
This is performed by keying in a command such as the following from the keyboard 17. For this reason, the BASIC language of the BASIC language operation unit 10 has two commands, ``VSAVE'' and ``VLOAD.''

FIG. 2 shows the operational flow of the BASIC language operating section 10 of the programmable controller according to the present invention. When the BASIC language operating unit 10 is activated by turning on the power, first, it is determined whether or not a user program is to be executed in the BASIC language (step 10). When executing a user program in BASIC language, the above-mentioned general variable area of the ROM 13 is initialized (step 20), and then the program is executed (step 30).

On the other hand, if the user program is not executed in the BASIC language, the next command to be executed is a timekeeping variable related command, ie, "VSAVE" or "
VLOAD" or not (step 40). If the next command to be executed is not a timekeeping variable related command, various direct commands or program editing are executed (step 50). .

When the next command to be executed is a time-retention variable related command, ie, "VSAVE" or "VLOAD," the variables in the above-mentioned retention variable area of the ROM 13 are stored in the external storage device 7 or The variables stored in the external storage device 7 are retrieved from the retained variable area (
Step 60).

FIG. 3 shows an example in which retention variable save/retrieve commands "VSAVE" and "VLOAD" are inserted at arbitrary locations in a user program written in BASIC language.

[0018]

Effects of the Invention As understood from the above explanation, according to the programmable controller according to the present invention, BASI
Among the variables used in a C language program, certain variables, that is, variables that should be retained, are stored in a variable retention memory area that is not initialized when the program is executed, so that the variables are retained without being erased when the program is executed. , the variable in the variable holding memory area is saved to the external storage device by the defined command, and the variable saved in the external storage device is retrieved to the variable holding memory area by the defined command, so the saving of this variable, Extraction can be easily performed when the BASIC program is stopped without requiring a special program. Also, by writing commands for saving and retrieving variables in the BASIC program, variables in the variable holding memory area can be stored and retrieved at arbitrary timing. As a result, the user does not need to program an algorithm for data exchange between the external storage device and the storage and retrieval of variables for reuse of variable data in programs written in the BASIC language.

[0019] In addition, if it is necessary to replace a module due to a hardware failure, even if the BASIC program cannot be executed, the command to save the retained variables can be executed and the interface with the external storage device can be operated. For example, by executing the save command, the current state of the retained variables can be saved as is to the external storage device.
By retrieving not only the program but also the retained variables from the external storage device after module replacement, data can be reused and the operating state before replacement can be restored.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of a programmable controller according to the present invention.

FIG. 2 B of the programmable controller according to the present invention
3 is a flowchart showing an example of the operation flow of the ASIC language operation unit.

FIG. 3 is a list diagram showing an example of a list of user programs written in BASIC language.

[Explanation of symbols]

1 CPU section 2 MPU 3 System ROM 4 RAM 5 Input/output interface 6 External storage device interface 7 External storage device 10 BASIC language operation section 11 MPU 12 System ROM 13 ROM 14 Programmable controller interface 1
5 Input/output interface 16 CRT 17 Keyboard 17

Claims (1)

[Claims] Claim 1: In a programmable controller having a user interface operated by a program in the BASIC language, variable retention for storing specific variables among variables used in the program in the BASIC language in a manner that they are not initialized when the program is executed. It has a memory area, and is configured to store variables in the variable storage memory area in an external storage device and retrieve variables stored in the external storage device into the variable storage memory area according to a defined command. A programmable controller.