JPS62196705A - Method and device for digital sequence control - Google Patents

Abstract

PURPOSE:To execute necessarily and exactly enough a verification of a control operation at every control dye by executing a comparison with a state of the previous execution cycle of a bit signal at every operation cycle of a digital sequence control, executing a report of a varied bit to the outside through communication, etc., and thereafter, executing a check mode operation for executing the next operation. CONSTITUTION:As for a contact point input signal 2, its state is reflected as 1 bit of a contact point input signal bit table 6, a sequence arithmetic unit 9 executes a sequence operation against various bit tables, and its result is reflected in a contact point output signal bit table 7, and becomes a contact point output in the end. By a CRT display device 5 which has been connected by a communication line, a bit signal, etc., of a digital sequence control device 1 are monitored. Also, the titled device is provided with a comparator circuit for detecting a difference of a state of the bit signal which has been monitored at every one execution cycle and a state of the bit signal of the previous execution cycle which has been stored in a retention circuit, and a controlling circuit for executing the next execution after the difference of the bit signal which has been detected by this comparator circuit, to the ontside through communication, etc., or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a digital sequence control method and apparatus for controlling chemical processes and electrical equipment.

[Background of the invention]

Conventional digital sequence control devices monitor the status of bit signals within the control device on a CILT screen, etc., and check whether the bit signals are on or off on the screen. However, since the communication speed from the control device to the CRT is slow compared to the control calculation speed, signal changes may be overlooked, and the small number of signal points that can be displayed on the CRT makes overall monitoring difficult, making complete operation confirmation difficult. It was difficult.

[Purpose of the invention]

The present invention provides a digital sequence control method that can perform necessary and sufficiently accurate verification of control calculations for each control cycle, and a digital sequence control method with such a check function.
The purpose is to make it possible to provide J-style fi.

[The key to the invention]

The digital sequence control method of the present invention is a digital sequence control device that periodically executes control to take in human contact power from the outside, perform sequence calculations, and output the contact outputs of the calculation results to the outside. Bit signals such as calculation intermediate signals are monitored every execution cycle, and the difference between the monitored bit signal state and the bit signal state of the previous execution cycle is reported to the outside via communication, etc., and then the next 1. The digital sequence control device of the present invention is a digital sequence control device that periodically executes control that takes in contact input from the outside, performs sequence calculation, and outputs the contact output of the calculation unit to the outside! ! +11? In the KI device, there is a storage circuit that stores bit signals such as human input signals, output signals, and calculation intermediate signals for each execution cycle, and a storage circuit that stores bit signals such as human input signals, output signals, and operation intermediate signals, and stores the states of the bit signals monitored every execution cycle and the A comparison circuit detects the difference between the state of the bit signal of the previous execution cycle stored in the memory circuit, and the difference between the bit signal detected by the comparison circuit is reported to the outside via communication etc. It is assumed that the control circuit includes a control circuit for carrying out the execution of the control circuit, and a changeover switch for switching to the control circuit.

The present invention compares the bit signal with the state of the previous execution cycle every calculation cycle of digital sequence control, reports changed bits to the outside via overconfidence, etc.
The purpose is achieved by executing check mode operations such as performing the next JI.

[Embodiments of the invention]

Examples will be described below.

1 to 3 are explanatory diagrams of one embodiment, in which FIG. 1 shows a state in which a digital sequence control device and a CRT message display device are connected through communication, and FIG. 2 shows the digital sequence control of FIG. 1. The internal configuration of the device is shown, and FIG. 3 shows the relationship between control calculations and operations in check mode. In these diagrams.

1 is a digital sequence control device, 2 is a contact input signal,
3 contact output signals, 4 is a communication line, 5 is a CRT display device t, 6, 7, 8 and 9 are a contact input signal bit table and a contact output signal bit table of the digital sequence control device 1, respectively. , the intermediate signal bit table and sequence performance information are shown.

In this digital sequence control device [11], the state of the contact input signal 2 is reflected as one bit of the contact manual signal bit table 6, and the sequence operation device [9 performs sequence operations with various bit tables]! L is performed, the result is reflected in the contact output signal bit table 7, and finally becomes a contact output. and.

The bit signals etc. of the digital sequence control device 1 can be monitored using the CR and T display device t5 connected through a communication line.

This sequence and arithmetic device are, for example.

A storage circuit that stores bit signals such as human input signals, output signals, and calculation intermediate signals for each execution cycle, and the state of the bit signal monitored for each execution cycle and the bits of the previous execution cycle that are stored in the storage circuit. A comparison circuit that detects the difference in the state of the signal, a control circuit that performs the first execution after reporting the difference between the bit signals detected by this comparison circuit to the outside via communication, etc., and a control circuit that performs the first execution of the control circuit - It consists of a check switch that turns off the system, but it can also be implemented using a computer. Next, the control calculations in the control method using this digital sequence 1ffllm device will be explained using FIG. When the check switch is off (a), normal control is performed, and the result of the 1ttlJffll operation K (b) is sent as is to the CR,T display device 5. The digital no-kense control method of the present invention is carried out in the case (C) where the check switch is on. In other words, when the check switch is on (C), all changes from the previous values in the contact input/output and intermediate bit table 6.7.8 are captured, and the CRT display shows which bits have changed and how. d), and the next control calculation is performed after the reporting is completed.

According to this digital sequence control method, when an external input changes, it is possible to completely check what kind of change has occurred in which signal using messages, so one person can check the signal status by displaying the signal status on a lamp or CRT. Compared to checking the situation, it can be completely confirmed, and the efficiency of confirmation is greatly improved.

〔Effect of the invention〕

The present invention makes it possible to provide a digital sequence control method that can perform necessary and sufficiently accurate verification of control calculations for each control cycle, and a digital sequence control device with such a check function, and has industrial effects. It is a dog.

[Brief explanation of drawings]

Fig. 8g1 is an explanatory diagram of an embodiment of the digital sequence control device of the present invention, Fig. 2 is an explanatory diagram showing the internal configuration, and Fig. 3 is an explanatory diagram showing the relationship between control calculations and operations in check mode. It is. ■...Digital sequence control device, 2...Contact input signal, 3...Contact output signal, 4...Communication line, 5
. . . CRT display device, 6 . . Contact input signal bit table, 7 . . . Contact output signal bit table, 8 . .
・Intermediate (1 other person)

Claims (1)

[Claims] 1. In a digital sequence control device that periodically executes control to take in contact input from the outside, perform sequence calculation, and output contact output as a result of the calculation to the outside, input signal, output signal, calculation bit signals such as intermediate signals,
A digital device characterized in that it monitors every execution cycle, reports the difference between the monitored bit signal state and the bit signal state of the previous execution cycle to the outside via communication, etc., and then performs the next execution. Sequence control method. 2. In a digital sequence control device that periodically executes control that takes in contact input from the outside, performs sequence calculation, and outputs the contact output of the calculation result to the outside, bit signals such as input signals, output signals, calculation intermediate signals, etc. of,
A storage circuit that stores information for each execution cycle; and a comparison circuit that detects the difference between the state of the bit signal monitored for each execution cycle and the state of the bit signal of the previous execution cycle that is stored in the storage circuit. and a control circuit that performs the next execution after reporting the difference between the bit signals detected by the comparison circuit to the outside via communication, etc., and a changeover switch that switches to the control circuit. Digital sequence control device.