JP3337145B2 - Error recovery device for sequence 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 an abnormality recovery device for a sequence control device.

[0002]

2. Description of the Related Art A sequence controller represented by a programmable controller inputs operation state signals of a plurality of devices, performs sequence processing based on these signals, and outputs operation commands to the plurality of devices. When an abnormal operation state of the device is input or an abnormal state is determined in the sequence processing, abnormal information is output, and the operator can recognize the abnormality on the display of the operation console or the CRT. The operator who recognizes the abnormal state removes the cause of the abnormality, operates various devices by itself until the sequence processing can operate normally, and then shifts the operation command of the device to the sequence processing.

As a method of restoring an error in a sequence control device, Japanese Patent Application Laid-Open No. 2-96201 discloses a method in which an abnormality occurs and a restoration sequence for the abnormality are stored in advance, and based on the stored restoration sequence when an abnormality occurs. It has been proposed to try to operate the device.

[0004]

However, in the prior art, since the operator performs the recovery operation, the operation greatly depends on the experience and subjectivity of the operator, and the optimum recovery operation cannot always be performed. There are problems that power loss often occurs and that an inexperienced operator cannot perform a recovery operation properly. On the other hand, in the technique disclosed in the above publication, a restoration sequence for restoring an abnormality must be stored, and it may happen that not all restoration sequences can be stored in the sequence control device. Further, since the processing of the restoration sequence is complicated, the operation may be performed in an erroneous restoration sequence. The problem to be solved by the present invention is to provide an apparatus for automatically performing a recovery sequence after an operator removes the cause of an abnormality without using an operator's operation and without having a storage unit for the recovery sequence. It is in.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an input unit for detecting operating states of a plurality of devices and a sequence based on an operating state signal of the devices from the input unit. In a sequence control device having a sequence control unit for performing processing and an output unit for giving operation commands to a plurality of devices based on a result of the sequence control unit, an operation command of the device is given by an operation command value set in advance according to a time schedule. A time schedule control unit, an operation command value storage unit that stores an operation command value when an operation command of the device is given by the time schedule control unit, and after removing a cause of the abnormality that has been temporarily stopped by detecting a device abnormality, based on the operation unfinished information of the operation command numeric storage unit
Optimal operation command value of the time schedule control unit
It is characterized by having an abnormality recovery unit for returning the value to a proper value .

[0006]

According to the above means, the recovery sequence after the operator has removed the cause of the abnormality is automatically performed only by the recovery input operation, irrespective of the judgment of the operator.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 10 is a time schedule control unit, 20 is an operation command numerical value storage unit, and 30 is an abnormality recovery unit. Operation completion signals from a plurality of devices, in this example, devices 1 to 4, are input to the time schedule control unit 10, and a device operation command for performing a preset sequence process based on the operation state signal is input to the time schedule control unit 10. Output. For example, as shown in the time schedule control time chart of FIG. 2, the devices 1 to 4 perform an opening / closing operation, and the operation command values in the time schedule control unit are such that the device 1 is open 1 / close 9 and the device 2 is open 11・ Close 19, device 3 open 21 ・ Close 3
4. Assume that the device 4 is set to open 6 / close 19 and a command of the device is given when the command counters match.

Next, the operation of the embodiment of FIG. 1 will be described with reference to the flowchart of FIG. The operation command value when the operation command of the device is given from the time schedule control unit 10 is stored in the operation command value storage unit 20, and the stored value is cleared when the operation of the device is completed (FIG. 3).
Steps 100 to 120). In FIG. 1, the abnormal signal is turned on when the value of the counter 12 is 10, and the device 1 goes to the open end and the close command is given, but the device 4 is not operated to the closed end.
Indicates that an open command has been given but has not been performed to the open end. At this time, it is assumed that the counter 12 is temporarily stopped due to abnormality detection. When the above abnormal state occurs (step 130 in FIG. 3), the operator first removes the cause of the abnormality (step 140). After that, the recovery ON push button is turned on to instruct automatic recovery (step 150). Abnormality recovery unit 3 when recovery input push button is on
0 indicates that the minimum value of the operation command value stored in the operation command value storage unit 20 is detected by the minimum value detection unit 32 (step 160), and the minimum value is forcibly set to the counter 12 of the time schedule control unit 10. (In FIG. 1, the numerical value “6”), and the counter is restarted (step 1).
70). As a result, a command to open the device 4 is given again with the count value 6, and then a command to close the device 1 is given with the count value 9, and the sequence is continued.

[0009]

As described above, according to the present invention, abnormality recovery of the sequence controller can be performed without depending on the judgment of the operator, and the program of the sequence controller can be simplified.

[Brief description of the drawings]

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

FIG. 2 is a time chart of a time schedule according to the embodiment of the present invention.

FIG. 3 is a flowchart of the embodiment of the present invention.

[Explanation of symbols]

10 time schedule control unit, 12 counter, 2
0 Numerical operation command storage unit, 30 error recovery unit, 32 minimum value detection unit

Claims (2)

(57) [Claims] An input unit for detecting an operation state of a plurality of devices, a sequence control unit for performing a sequence process based on an operation state signal of the device from the input unit, and a plurality of units based on a result of the sequence control unit. A sequence control device having an output unit for giving an operation command to the device, a time schedule control unit for giving a device operation command with an operation command value set in advance by a time schedule, and a device operation command from the time schedule control unit. The operation command numerical value storage unit that stores the operation command value when is given, and the time schedule control based on the operation incomplete information of the operation command numerical value storage unit after removing the cause of the abnormality that has been temporarily stopped by the device abnormality detection. Operation command value
An error recovery device for a sequence control device, comprising: an error recovery unit for returning to an optimum value . 2. The apparatus according to claim 2, wherein said time schedule control unit controls
Counts the operation command value when the operation command is given
Counter that stops when an error is detected, and
After leaving, the operation command numerical value storage unit
Minimum value of stored operation command value is detected by minimum value detector
And the minimum value is forcibly set to the counter.
And an abnormality recovery unit for restarting the addition of the counter.
2. The sequence control device according to claim 1, wherein
Abnormal recovery device.