JPS6111805A - Sequence control device - Google Patents

Abstract

PURPOSE:To synchronize the transmission/reception of data easily by forming a flag storing part to be accessed from respective operation parts and determining the execution of processing of the succeeding instruction or after on the basis of the status whether the flag storing part is set or not. CONSTITUTION:In a sequence control device, operation parts 3, 4 execute the operation of data inputted from an external apparatus 8 through an input part 6 in accordance with a program stored in storage parts 1, 2 and transfers the operated result to the external apparatus 8 through an output part 7. In this case, the flag storing part 9 to be directly accessed from respective operation parts 3, 4 is formed to store an instruction for jumping its operation to a specified address if the flag is set up or executing the succeeding instruction, and if not set up, setting up the flag and executing the succeeding instruction without jump and also storing an instruction for resetting the flag. Consequently, the synchronization of the transmission/reception of data between plural programs can be guaranteed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a sequence control device that has a plurality of arithmetic units and processes a plurality of programs in parallel.

[Background of the invention]

FIG. 1 shows an example of a conventional parallel processing type sequence control device. Based on the data taken in from the external device 8 through the input unit 6, calculation units 3 and 4 perform calculations according to the programs stored in the storage units 1 and 2. The calculation result is passed to an external device through the output section 7. Reference numeral 5 denotes an internal output storage section for temporarily storing data that does not need to be directly output to the outside, such as the progress of one calculation. In the case of the conventional sequence control device as described above, since the calculation units 3 and 4 each perform calculations asynchronously,
There was a drawback in that the transfer of data between them could not be synchronized. For example, when performing two-axis control of a positioning device, the calculation unit 3 takes in X-axis position coordinate data and Y-axis position coordinate data according to the program stored in the storage unit 1, and outputs the data to the internal output storage unit 5. Based on this, the partner programs in storage units 1 and 2 perform calculations such as commands for the next position and position coordinates. In such a case, when the calculation unit 3 stores the X-axis data in the internal output of 5,
There is also a possibility that the arithmetic unit of 5 takes out data from the internal output of 5 and performs arithmetic operations. At a timing like this, only the X-axis data is the latest data, and the Y-axis position coordinate data remains the old data. Even if the calculation unit 4 performs calculations based on these data, the result will not be correct. cannot be obtained. Similarly, immediately after the calculation unit 4 reads out the X-axis coordinate data from the internal output storage unit 5, the calculation unit 3 may update the data for both the X and Y axes. As described above, the conventional device has the drawback that the simultaneity of the data set in the storage section 5 cannot be guaranteed.

In order to prevent this, a method was also adopted in which the data was updated by using the gap in the cyclic processing after the program in the first storage section ended until it was executed again from the beginning. The problem was that the data was updated infrequently and the response was slow.

[Purpose of the invention]

An object of the present invention is to provide a sequence control device that can easily synchronize data reception and transfer when processing a plurality of programs in parallel.

[Summary of the invention]

A feature of the present invention is that a flag storage section that can be accessed by each arithmetic unit is provided, and whether or not to perform processing following the next instruction is determined depending on whether or not this flag storage section is set.

By checking the flag storage unit, the receiver can determine whether or not it is allowed to access the transfer area, so that data reception and transfer can be synchronized.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 3 is a block diagram of an example of the sequence control device of this embodiment. Based on the data taken in from the external device 8 via the input unit 6, the calculation unit 3.4 performs calculations according to the program stored in the storage unit 1.2. The calculation result is passed to the external device 8 through the output section 7. Reference numeral 5 denotes an internal output storage section J, which is used to temporarily store data that does not need to be directly output to the outside, such as intermediate progress of calculations.

The feature of this embodiment is that it is provided with a flag storage section 9 that can be accessed directly from each calculation section 3.4, and if this flag is set, it jumps to the specified location, and if it is reset, it sets the flag and jumps. First, it has an instruction to be executed from the next instruction (temporary KIRI81!1RVE instruction), and an instruction to reset this flag (hereinafter referred to as IF
(referred to as the RIK instruction).

In order to maintain the simultaneity of receiving and passing data, it is necessary to
), before the program 10 that sets data in the internal output storage section 5, R'1. Insert the BnRVR command. The processing means 3.4 which executes this instruction first checks the flag and, if it is not set, sets it to indicate that other arithmetic units are busy updating data. After Program 10 ends, 'PRF! The shift flag storage unit 9 is reset by the Fi instruction. The execution order of the program at this time is shown in FIG. 3(b). Solid lines indicate program execution, and dashed lines indicate jumps. This example is a Silkens program, so cyclic processing is performed. On the other hand, if the -7 lag storage section 9 is set when the RE8KRVB instruction is executed, the arithmetic section 3.4 jumps to the jump destination indicated after RBBRRVB without proceeding to the next instruction.

FIG. 3(c) shows the execution order at this time.

Due to the above I'tlli81RVK, F'R, and BB instructions, the receive will always have the flag 9 set while updating the passing data, and other arithmetic units cannot access this data, so the data are all updated PRE
This occurs because the data is read after the K instruction is executed, and the simultaneity of the data to be read can be ensured.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a sequence control device that can guarantee the simultaneity of receiving and passing data between multiple programs without sacrificing response speed. .

[Brief explanation of drawings]

The first cause is a Plutz diagram showing an example of a conventional parallel processing type sequence control device, and FIG. 2 is a block diagram of a sequence control device showing an embodiment of the present invention, and FIG. 3 is a block diagram of a sequence control device showing an embodiment of the present invention. It is a figure which shows an order. 1.2...Program storage unit, 3.4...Arithmetic unit,
5... Internal output memory, 6... Input section, 7... Output section, 8... External device, 9... Flag storage section, 10
...Data is delivered to you Program agent Patent attorney Akio Takahashi $ 1

Claims (1)

[Claims] It has a storage part that stores a plurality of programs, an input part that takes in signals from an external device, and a plurality of calculation parts that perform calculations according to the plurality of programs read from the storage part based on the data taken in from the input part. In a sequence control device comprising a control section and an output section for transmitting the calculation result to an external device, a flag storage section accessible from the calculation section is provided, and a flag storage section is set. , a sequence control device comprising processing means for determining whether or not to perform processing subsequent to the next command.