JPH04205311A - Distributed controller - Google Patents

Abstract

PURPOSE:To change or correct a sequence logic diagram without stopping the operation of a control station by changing the input signal state of the sequence logic diagram displayed on a screen after designating input and output bypass means. CONSTITUTION:A logic diagram changing means 24 has the function of CAD and corrects or changes the sequence logic diagram displayed on the screen of a CRT while receiving an instruction caused by a keyboard or a mouse. An input bypass means 25 and an output bypass means 26 separate real input and output signal states and the states of input and output signals displayed on the screen. An input image changing means 27 operates the input signal state of the sequence logic diagram displayed on the screen and makes the logic diagram coincident with the real output signal state. After the coincidence, the output bypass means is canceled so as to prevent fluctuation in outputs. Thus, without stopping the sequence control operation at the control station, the sequence logic diagram can be easily changed or corrected.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides an engineering station that functions as a man-machine interface with an operator and performs system construction and various engineering tasks;
This is a distributed control device consisting of a control station that is loaded with various programs and data built at the engineering station and performs process control according to the programs. It is equipped with a function to graphically display a sequence logic diagram that clearly displays the steps of sequence control, which is the main function of the station, and allows for easy online maintenance of this sequence logic diagram function. This invention relates to a distributed control device.

<Prior Art> Decision tables and sequence logic diagrams are used to express sequence order control in an easy-to-understand manner.

FIG. 5 is a diagram showing an example of a sequence logic diagram. In the sequence logic diagram displayed (described) in this way, when the AND between the input (IN) and the input (IN)2 is established, the flip-flop FF is set and the output is 1.
(OUTI) is output and when input (IN) 3 is established, flip-flop FF is reset and output 2 (O
This means that UT2) is output.

<Problems to be Solved by the Invention> By the way, when the sequence logic diagram (sequence order) displayed in this manner is changed or modified online on the engineering station, the following problems occur.

Now, for example, the setting conditions for the flip-flop FF can be changed from the state shown in FIG. 5(a) to the sequence logic diagram shown in FIG. 5(b).
is set, and the output of the flip-flop FF and the input 1
Let us assume a case where the output is changed so that when the AND of is satisfied, the output is sent.

Flip-flop FF is on its input or set side.

If both reset sides are off, the previous value is held. For this reason, when the change is made as shown in FIG. 5(b), the state of the element that existed before the change (the function of an AND element) is returned to the position of the flip-flop FF. Also, when a new flip-flop is created, its output is similarly undefined, and each output 1.2 will fluctuate, causing online problems.

This was a problem when performing on-site maintenance (changing the order of sequences without stopping the control station).

The present invention has been made in view of these points, and is a distributed system that allows changes and modifications to sequence logic diagrams without stopping the operation of the control station, thereby improving maintainability during online maintenance. The purpose is to provide a control device.

Means for Solving the Problems> The present invention that achieves the above objects has a function of displaying a control station and sequence control procedures executed by the control station in a sequence logic diagram on a display screen. and an engineering station, the engineering station further comprising sequence logic diagram display means for displaying sequence control procedures to be executed in the control station on a display screen in the form of a sequence logic diagram. , the sequence displayed on the screen
Logic diagram changing means for changing the logic diagram; and an input bypass for separating the actual input signal state from the control station and the input signal state displayed on the screen in the sequence logic diagram displayed on the screen. output bypass means for separating the state of the output signal actually output to the control station from the state of the output signal displayed on the screen in the sequence logic diagram displayed on the screen; and an input image changing means for changing the input signal state of the sequence logic diagram displayed on the screen after specifying the means and the output bypass means.

<Operation> The logic diagram changing means has a CAD function, and the C
Correct or change the sequence logic diagram displayed on the RT screen by receiving instructions using the keyboard or mouse.

The input bypass means and the output bypass means are connected to the actual input,
Separate the output signal state from the input signal and output signal states displayed on the screen. In the bypass state using this bypass method (5-), the sequence displayed on the screen
Even if the Rontz diagram is changed, the actual output signal will not change.

The human power image changing means operates the human power signal state of the /-Ken λ logic diagram displayed on the screen [17] and matches the logic diagram with the actual output signal state. By releasing the output bypass means after the match is made, fluctuations in the output are prevented.

<Example> Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a control station that controls the process; for example, it inputs various sensor signals and contact signals installed in the field 12, feed pack control means 11 performs feed pack control, and sequence control means 1.
It has two caps, from which the control output is output to an operating end such as a valve.

2 is equipped with a CRT2E and Geehaut 22 as man-machine interfaces with operators, and is used for system construction and various other functions. This is an engineering link station that performs various functions, and is connected to the control station 1 via a paper passing line BS. Various blocks and databases constructed at this engineering link station 2 are linked to the control station 1 via the communication four-wire BS, and the control station 1 is linked to the control station 1 according to the rope-linked program. , for example, to perform sequence control. Further, the control status of the control station 1 is sent to the engineering link station via the paper passing line BS 1-, so that these can be displayed on a monitor at the engineering station.

In the engineering link station 2, 23 is a sequence logic diagram display means for displaying sequence control procedures executed by the control station 1 on a display screen (CRT) 21 as a sequence logic diagram. 7, so that the operating status of the sequence control executed by the control station 1 can be displayed by changing the display color, line type, etc. every moment.

Reference numeral 24 denotes a logic diagram changing means for changing the sequence logic diagram displayed on the screen, which is equipped with, for example, C and AD functions, and is capable of changing and correcting the connection state of each element in a format similar to CAD. It is configured so that it can be done.

Reference numeral 25 denotes an input bypass means for separating the actual input signal state from the control station 1 side from the input signal state displayed on the screen in the sequence logic diagram displayed on the screen. When this manual bypass means 25 is specified, the sequence logic diagram and the input signal are separated, and even if the input signal changes 1-, the input value of the sequence logic diagram 25 is the input state when the input bypass is performed. Human power image changing means 27 that is retained and will be explained later
It is possible to change the input image by

Reference numeral 26 denotes an output bypass means for separating the state of the output signal actually output to the control station 1 from the state of the output signal displayed on the screen in the sequence logic diagram displayed on the screen. When this output bypass means 26 is specified, the sequence logic diagram and the output signal are separated, and even if the output value of the connected logic element changes from 1 to 1, the actual output signal does not change. After the output bypass is specified, the output state of the output signal when the output bypass was specified I7 is maintained.

The input image changing means 27 is for changing the input signal state of the sequence logic diagram displayed on the screen after specifying the input bypass means 25 and the output bypass means 26.

Reference numeral 28 is a database storage unit in which programs and data generated by this engineering station 2 are stored, and 29 is a communication means for communicating loading of programs and databases to the control station 1, collection of various data from the control station side, etc. via the line BS].

The operation of the device configured as described above will be explained as follows.

FIG. 2 is a diagram showing an example of a sequence logic diagram displayed on the CRT screen by the logic diagram display means 23.

The logic diagram display means 23 collects data from the control station 1 side via the communication means 29, and if the input signal is on, it displays the corresponding input terminal figure on the left side in red, and if it is off, it displays the corresponding input terminal figure in red. Displayed in cyan. Also, if the line connecting each logic is established (when it is on), it is displayed as a solid red line, and when it is not established (when it is off), it is displayed as a solid red line.
Displayed as a cyan dashed line.

If the output signal is on, the corresponding output terminal figure on the right side is displayed in red, and if it is off, it is displayed in cyan.

Now, the contents of the sequence logic diagram are shown in Figure 5 (a).
Let us consider the case where the changes are made as shown in figure (b). Also, assume that before the change, either input (IN) 1 or input (IN) 2 was turned on and then turned off again.

At this time, the flip-flop FF is set (turned on). This state is shown by the thick line extending from the S side output of the flip-flop FF, and the output connected to this (OUT
)1 is also turned on (this state is similarly expressed in a general outline), and the output operation is performed.

If the contents of the sequence logic diagram shown in FIG. 5(b) are modified from this state, the flip-flop FF will move to the position of the OR element before the change, but the flip-flop FF will move to the position of the OR element before the change. Since the inputs on both the S side and the R side remain off, the flip-flop FF performs the operation of holding the previous value, and takes over the established state (that is, the off state) of the OR element before modification. For this, the output (
OUT) 1 is turned off, output (OUT) 2 is turned on,
The output state has changed even though the input state has not changed.

In this case, it seems that the state of the flip-flop FF after the change should inherit the state before the change, but this may be inconvenient if there are multiple flip-flops FF or if a new flip-flop is created. It is not practical because it occurs.

The present invention improves these points.

FIG. 3 is a flowchart showing the procedure for online maintenance of a sequence logic diagram by the apparatus of the present invention, and FIG. 4 is a diagram showing changes in the sequence logic diagram.

First, as shown in FIG. 4(a), output bypass is designated by the output bypass means 26 in the target sequence logic diagram displayed on the screen. Next, online maintenance is performed by the logic diagram changing means 24. In this example, the flip-flop FFO position is changed as shown in (b). In this case, the state of the logic changes as described above, but the output does not change because the output operation is bypassed. Therefore, the logic and output are not matched at this stage.

The state of this logic and output can be monitored by the sequence logic diagram operating state display function of the engineering control station.

Next, in order to match the target sequence logic diagram and the output signal, the input bypass means 25 specifies an input bypass. Then, the input image changing means 27 is used to turn the input (IN) 2 from the off state to the on state, and after inverting the flip-flop FF,
Perform the operation to turn it off again and match the output state with the logic diagram as shown in (C). After these operations, release the input bypass, confirm that the matching is achieved,
Release the output bypass as shown in (d).

By taking the above-described procedure, control can be restarted after online maintenance without causing the same fluctuation in output.

In this embodiment, a case has been described in which the system is composed of a control station and an engineering station, but an operator station is connected to a communication line and information is concentrated there for control operation and monitoring. In addition, the operator station may also have the function of the engineering station described above.

<Effects of the Invention> As explained in detail above, according to the present invention, the sheet control operation at the control station is not stopped;
It is easy to change and modify non-nonce logic diagrams, which significantly improves maintainability.

[Brief explanation of the drawing]

Figure 1 is a conceptual configuration diagram showing an embodiment of the present invention, Figure 2 is a diagram showing an example of a sequence logic diagram displayed on a CRT screen by the logic diagram display means, and Figure 3 is a diagram showing an example of the sequence logic diagram displayed by the logic diagram display means on a CRT screen. There is a flowchart showing the procedure for online maintenance of the sequence logic diagram, FIG. 4 is a diagram showing changes in the sequence logic diagram, and FIG. 5 is a diagram 'C' showing an example of the sequence logic diagram. ]...Control station 2・Engineering station 21-...C
RT screen 23...Sequence diagram display means 24...Logic diagram changing means 25...Manual bypass means 26...Output bypass means 27...Input image changing means Patent applicant: Yokogawa Electric Corporation 1' -To Party B15,--1 Agent Patent Attorney Ozawa Shinpan Ira' Figure 3 Figure 4 Output Bypass Designation F

Claims (1)

[Scope of Claims] A distributed control device comprising a control station and an engineering station having a function of displaying sequence control procedures executed by the control station in a sequence logic diagram on a display screen. , the engineering station includes a sequence logic diagram display means for displaying sequence control procedures executed at the control station as a sequence logic diagram on a display screen, and a sequence logic diagram displaying means for changing the sequence logic diagram displayed on the screen. , logic diagram changing means for modifying, and input bypass means for separating the actual input signal state from the control station and the input signal state displayed on the screen in the sequence logic diagram displayed on the screen. , in the sequence logic diagram displayed on the screen, output bypass means for separating the state of the output signal actually output to the control station and the state of the output signal displayed on the screen; the input bypass means; 1. A distributed control device comprising: input image changing means for changing an input signal state of a sequence logic diagram displayed on a screen after specifying an output bypass means.