JPH01118902A - Control system for pc data transfer - Google Patents

Abstract

PURPOSE:To facilitate generation of a ladder program by interlocking the data transfer instructions with each other. CONSTITUTION:A data transfer instruction EPCA 7 is set and the external tool correction data is never transferred to a shared RAM as long as a display data transfer instruction 2 is kept under execution. While a data transfer inhibition flag EPCB 3 is set and the instruction 2 is not executed when the transfer of the external tool correction data is started. Thus data are transferred after other data transfer instructions are through. Therefore no special interlock is required with a ladder program. Thus the generation of the ladder program is facilitated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data transfer control system for a PC, and particularly to a data transfer control system for a PC that allows different data to be easily transferred via the same address. Technology] In a PC (programmable controller), different data may be transferred via the same address at different times. For example, in a PC coupled to a numerical control device (CNC), data requested by the numerical control device (CNC) is transferred via the same address at different times.

For this purpose, we interlock each other so that one data is not transferred while the other data is being transferred.
This was to prevent data from being accidentally transferred or corrupted.

[Problem that the invention seeks to solve]

However, these interlocks were generally performed by a user program called a ladder program. For this reason, if the program is inaccurate, data transfer may not be successful and other data may be destroyed. Particularly in ladder programs, different programs are divided and executed at different levels of priority, so it has been difficult to create a ladder program that takes these priorities into consideration.

The purpose of the present invention is to solve the above problems and to provide a PC that can easily transfer different data via the same address.
The purpose of this invention is to provide a data transfer control method.

[Means for solving problems]

In order to solve the above problems, the present invention provides a data transfer control method for a PC (programmable controller) in which different data is transferred via the same address. A PC comprising: a first data transfer instruction having a data transfer prohibition flag; and a second data transfer instruction having a data transfer prohibition flag that is set upon the start of execution of the first transfer instruction. A data transfer control method is provided.

[Effect]

For two data transfer instructions, the data transfer instruction prohibition flag is set at the start of the other data transfer instruction, so the data transfer instructions are not executed at the same time, and the data transfer instruction is executed after the other data transfer instruction is completed. Ru.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a hardware configuration diagram of a data transfer control system for a PC according to an embodiment of the present invention. In the figure, 30 is PM
CPU3 with C (programmable machine controller)
1. It has a ROM 32, a RAM 33, and an interface (INT) 34 with the outside. The ROM 32 stores a management program for controlling the PMC, a ladder program for controlling the machine, and the like. 33 is a RAM in which various data are stored. External tool correction data, which will be described later, is also temporarily stored in this RAM 33. The interface 34 exchanges input (DI) and output (DO) with the machine side.

The CPU 31, ROM 32 and RAM 33, and interface 34 are connected to each other via a bus.

40 is a CNC (numerical control device), and in the figure CNC
PU41. Only the shared RAM 42 and display device 43 are shown, and other components are omitted. PMC30!
=The CNCs 40 can exchange data with each other via the shared RAM 42.

Here, external tool correction data and PM
The display data on the C side will be explained as an example. The external tool compensation data is read by the PMC 30 from the interface 34 and stored in the RAM 33, and then transferred to the shared RAM 42 when the RAM'M 42 is not used for other data transfer. This is data that is transferred to the CNC 40 side via the CNC 40 side, and a correction operation is performed on the CNC 40 side.

In addition, the display data here refers to display data programmed in the ladder program of the PMC30,
This is data for displaying the alarm status etc. on the machine side on the display device 43 of the CNC 40.

This external tool correction data and display data are stored in the shared RAM42.
is transferred to the CNC 40 via the same address. Therefore, if data are transferred simultaneously without interlocking each other, there is a risk that the data will be confused with the data of the other party or the data will be destroyed.

Next, the execution method of the data transfer control method will be described. FIG. 2 shows an example of a ladder program using the data transfer control method. In the figure, ■ is a contact point for starting a display data transfer command. 2 is a display data transfer command which is a functional command for transferring display data, and 3 is a data transfer prohibition flag (EPCB), which is set at the start of transfer of external tool correction data, which will be described later. 4 is a coil that is set at the start of display data transfer and becomes 'IJ' during the transfer period.

5 is an interface 34 for transmitting tool correction data from outside.
This is a collection of instructions to be read into the RAM 33 via the . 6 is an interlock command, which actually consists of external tool correction data transfer and a data transfer prohibition flag (EPCA) 7 that prohibits this. Data transfer prohibition flag (E
PCA)7 is set at the start of display data transfer command 2.

Therefore, while the display data transfer instruction 2 is being executed, the data transfer instruction (EPCA) 7 is set, and the external tool correction data is not transferred to the shared RAM 4'2. Conversely, when external tool correction data transfer starts, the data transfer prohibition flag (EPC
B) 3 is set and the display data transfer instruction is not executed. Data transfer is performed after other data transfer instructions are completed.

As a result, there is no need to create a special interlock on the ladder program, making it possible to easily create a ladder program.

Although the above explanation is based on a PMC, it is equally applicable to a normal PC (programmable controller).

Furthermore, although the display data transfer command and the external tool correction data transfer command have been described, other transfer commands can be programmed in the same way.

〔Effect of the invention〕

As explained above, in the present invention, the data transfer instructions are configured to be interlocked with each other, so there is no need to establish an interlock on the ladder program, making it easy to create a ladder program, and data transfer instructions passing through the same address This can prevent problems such as data confusion or destruction of the other party's data.

[Brief explanation of the drawing]

FIG. 1 is a hardware configuration diagram of a data transfer control method of a PC according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a ladder program of a data transfer control method according to an embodiment of the present invention. 2---1--Display data transfer instruction 3---11-
-----Data transfer prohibition flag (EPCB) 6--
・−・Interlock instruction 7−−−−−−−−・−Data transfer prohibition flag (EPC
A) 30-----1...PMC (programmable)
Machine controller) 31------1--Processor 33--m---RAM 40--1--...-CNC (numerical control device) 41.
−−−−−−−−1 Bromo Nsa 42−・−・・～
Shared R/'i M Applicant Fanuc Co., Ltd. Agent Patent Attorney Takeshi Hattori Dlo D/I Figure 1

Claims (1)

[Claims] (1) In a PC data transfer control method in which a PC (programmable controller) transfers different data via the same address, the first data has a data transfer prohibition flag that is set at the start of the second data transfer command. A data transfer control method for a PC, comprising: a transfer instruction; and the second data transfer instruction having a data transfer prohibition flag that is set upon the start of execution of the first transfer instruction.