JP3360742B2 - Distributed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed type for monitoring the operation such as starting / stopping a motor and a pump installed in a process, opening / closing an on / off valve, and the operating state of an operating end for the operation. More specifically, the present invention relates to a configuration of a switch instrument provided in a control device that is in charge of various control calculations and that outputs an on / off operation signal to an operation terminal installed in a process. .

[0002]

2. Description of the Related Art A distributed control device includes a plurality of control devices (field control stations) distributed in accordance with the scale of a process to be controlled, and an operator station for performing control operation and monitoring the process. Are connected to each other via a communication bus.
In such a distributed control device, the control device includes, for example, a feedback control instrument having a function of performing PID control calculation, a sequence control instrument for performing sequence control, start / stop of motors and pumps, and an on / off valve. A plurality of switch instruments and the like for performing opening and closing operations of the instruments are prepared, and these instruments can be appropriately combined and used according to a process for applying the instruments.

FIG. 4 is a conceptual diagram showing the configuration and operation of a conventional switch meter provided in a control device. In the figure, FC is a control device including a switch meter SK that outputs an ON / OFF signal to an operation terminal AC such as a motor-operated valve installed in a process, and OP is operation of a switch meter or the like in the control device FC. It is an operator station in charge of operation and monitoring, and has a display screen such as a CRT and a pointing device such as a keyboard and a mouse. Various graphics and information convenient for process operation monitoring are displayed on the display screen of the operator station OP. For example, at the time of operation and monitoring of the switch meter, an instrument diagram for performing operation monitoring of the switch meter SK is displayed as shown in the figure.

[0004] When the operator operates (presses or designates) the operation button of the switch instrument diagram displayed on the display screen, an instruction signal is given to the corresponding switch instrument in the control device FC, and the operation signal is given therefrom. An ON / OFF signal corresponding to the operation is output to the terminal AC. The operation end (electromagnetic valve) is provided with, for example, a limit switch LSW indicating the movement thereof, and a signal indicating the operation state of the operation end is returned to the switch meter as an answer back signal. The switch meter in the control device monitors the movement of the operation end from the answerback signal and displays the operation state of the operation end on the instrument diagram of the display screen.

[0005]

In a switch meter having such a structure, when the operating end is, for example, a valve (valve), an operation signal MV is actually output to the valve and then the valve is opened or closed. Starts, and some waiting time is required before it is reflected in the answer back signal, but the switch meter cannot output an alarm based on the result of the check during this time (this state is called a check mask state). However, in the conventional apparatus, there is a problem that it is not possible to know that the above-mentioned check mask state exists in each switch meter. For this reason, conventionally, when it is necessary to check whether the switch meter is in the check mask state described above, the operation signal MV output from the switch meter is always compared with the signal PV input as the answer back signal, The results had to flow.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and makes it possible to easily confirm / recognize whether or not a switch instrument is in a check mask state as described above. It is an object of the present invention to provide a distributed control device that can be easily connected to an instrument.

[0007]

According to the present invention, which achieves the above object, an on-off terminal provided in a process is provided.
A control device including a switch meter that outputs an OFF operation signal, and a distributed control device including an operator station in charge of operation and monitoring of a switch meter and the like in the control device, wherein the switch meter includes: An operation signal output unit that outputs an operation signal to the operation terminal in response to an operation from the operator station, and compares the operation signal output to the operation terminal with an answerback signal indicating an operation state from the operation terminal to perform an operation. monitoring means for monitoring the operating state of the edge, and counter means for counting a predetermined check mask time from outputting the operation signal to the operation terminal until it is actually reflected in the operation of the operating end, the operation Signal
If not equal to the answer back signal, while the count value of the counter means is within the check mask time,
Check that the monitoring means outputs an alarm during the monitoring operation.
Outputs a signal indicating that the check masked by masking the seeking operation, when exceeding the check mask time, before
And a mask signal output means for outputting an alarm signal to the monitoring means .

[0008]

In the counter means, a check mask time corresponding to the operation terminal to be operated is set in advance, and when the operation signal MV is output from the signal output means to the operation terminal, counting up is started. The mask signal output means monitors the count value of the counter means, and when the value is within the check mask time, masks the alarm output operation of the monitor means and outputs a signal indicating that the apparatus is in the check mask state. Output.

Thus, for example, the sequence control instrument provided in the control device uses the signal from the switch instrument for control while referring to the signal indicating the check mask state from the mask signal output means. Becomes possible.

[0010]

An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram showing one embodiment of the present invention. In the figure, OP is an operator station, FC is a control device including a switch instrument for outputting an ON / OFF operation signal to an operation terminal AC installed in a process, and is a control device including an operator station O via a communication bus BS.
Connected with P. An instrument diagram such as a switch instrument is displayed on the display screen of the operator station OP as necessary, and a command signal by operating the instrument diagram (for example, operating with a touch operation or a mouse) is transmitted through the communication bus BS. Then, it is sent to the corresponding control device. In the control device FC, a large number of control instruments for performing a feedback control operation and a large number of sequence control instruments for performing a sequence control operation are provided in addition to a switch instrument and the like.

In the switch meter SK in the control device FC, 1 is an operation signal output means for outputting an ON / OFF operation signal MV to the operation terminal AC in response to an operation from the operator station OP, and 2 is an operation terminal. A monitoring unit that compares the operation signal MV output to the AC with the answerback signal PV indicating the operation state from the operation terminal AC, and monitors the operation state of the operation terminal AC.
In such a case, a function of outputting an alarm signal ALM is provided.

Reference numeral 3 denotes counter means, which is an operation signal output means 1
Output the operation signal MV to the operation terminal AC from the control signal MV, and then start counting up.
Thus, a predetermined check mask time until the operation is actually reflected on the operation of the operation end is counted. Reference numeral 4 denotes a mask signal output means, which counts the value of the counter means 3 in advance.
During a check mask time set according to the operation end, a check operation for outputting an alarm is masked in the monitoring operation of the monitoring means 2 and a signal ANCK indicating that the state is in the check mask state. Is output.

The operation of the apparatus having the above-described structure will be described below. FIG. 2 is a flowchart showing an example of the operation, which is started at a predetermined control cycle (for example, 1 sec). First, when the operator intends to operate a specific operation terminal (valve) installed in the process, the operator displays the instrument diagram of the corresponding switch instrument on the display screen of the operator station OP, and uses the instrument diagram to display the instrument diagram. Perform necessary operation commands. Upon receiving an operation command from the operator station OP, the corresponding switch meter SK in the control device resets each status flag, and the operation signal output means 1 outputs the current operation command value MV and the previous operation command value (previous MV). ), And in the case of a mismatch, ie, MV
Is changed, the mask counter 3 is cleared to zero.

When this time MV = last time MV, monitoring means 2
Inputs the answerback signal PV from the operation terminal AC and monitors that PV = MV (steps 1 to 5).
4). That is, for example, if an operation signal MV for opening a valve is output to an operation terminal AC such as a valve, a limit switch provided on the valve outputs an answer signal indicating “open” corresponding to the operation signal. The signal PV is input soon, and the monitoring means 2 outputs the answer back signal as the PV.
= MV.

Here, when PV = MV is not satisfied (PV ≠ MV), it is determined whether it is within the answer back mask time TM (step 5). That is, the counter means 3 includes
A check mask time TM (corresponding to a time from when an operation signal is given to the valve to when the valve is actually opened or closed) corresponding to the operation terminal AC to be operated is set in advance, and the mask signal is set. The output unit 4 refers to the count value of the counter unit 3 and determines whether the value is within the check mask time TM. If the time is within the check mask time TM (Yes in step 5), the counter means 3 is counted up, and the ANC indicating that the monitoring means 2 is in the check mask state is set.
The K flag is set (steps 6 and 7).

Subsequently, the state of each flag is reflected on the data, and the process is terminated (step 10). This allows other control instruments (eg, sequence control instruments) in the controller to
By referring to the NCK flag, it can be easily confirmed that the corresponding switch meter is in the check mask state. In step 4, when the monitoring means 2 determines that PV = MV, the operating terminal AC determines that it is operating normally in response to the operation output signal MV, and sets the counter means 3 to count over. (Step 8). If the check mask time TM is exceeded in step 5, the monitoring means 2 determines that PV = MV has not yet been reached even after the set check mask time TM has elapsed. Judge that the operation of AC is abnormal,
An alarm flag is set and an alarm signal ALM is output (steps 9 and 10).

The state set in each flag can be freely referred to in other control instruments in the control device. Further, each data (answer back signal PV, ALM signal, ANCK signal) output from the switch instrument SK is transmitted to the operator station OP, and the state is displayed on the instrument diagram as needed. In this embodiment, the monitoring means 2 always outputs the answerback signal PV.
Is monitored (PV = MV) if the output operation signal MV matches the output operation signal MV.
= MV (PV ≠ MV), alarm signal A
Although the LM is configured to output the LM, the monitoring operation of whether the PV = MV in the monitoring unit 2 may be performed after a set check mask time has elapsed.

FIG. 4 is a flowchart showing the operation in this case. The basic operation is the same as that of FIG. 2, but the judgment whether the check mask time has elapsed (step 14) is performed before the monitoring means 2 judges whether PV = MV (step 15). They are different.

[0019]

As described above in detail, according to the present invention, a signal indicating a check mask state can be output to a switch meter provided in a control device. Can be easily confirmed and grasped. Therefore, by referring to the ANCK signal indicating the check mask state from the switch instrument, it is possible to simplify exchange of signals with each switch instrument, sequence control instrument, and the like.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart showing an example of the operation of the present invention.

FIG. 3 is a flowchart showing an example of another operation of the present invention.

FIG. 4 is a conceptual diagram showing the configuration of an operation of a switch meter provided in the control device.

[Explanation of symbols]

 FC control device OP operator station BS communication bus SK switch meter AC operation terminal 1 operation signal output means 2 monitoring means 3 counter means 4 mask signal output means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G05B 19/00-19/16 G05B 23/00-23/02

Claims (1)

(57) [Claims] A control device including a switch instrument for outputting an on / off operation signal to an operation terminal installed in a process, an operator station in charge of operating and monitoring a switch instrument and the like in the control device. An operation signal output means for outputting an operation signal to an operation terminal in response to an operation from an operator station, and an operation signal output to the operation terminal. Monitoring means for monitoring the operation state of the operation end by comparing an answer back signal indicating the operation state from the operation end; and outputting an operation signal to the operation end and then reflecting the operation signal on the operation of the operation end. A counter for counting a predetermined check mask time until the operation signal is not equal to the answerback signal.
If the count value of the counter means is within the check mask time, the monitoring means outputs an alarm during the monitoring operation.
Output a signal indicating that it is in the check mask state, and check the check mask time.
And a mask signal output means for outputting an alarm signal to the monitoring means when the signal exceeds the threshold value .