JPH0344709A - External trouble detecting device - Google Patents

Abstract

PURPOSE:To automatically change the expected value in response to the change of a control subject and to detect the trouble of the control subject by storing plural pieces of expected value corresponding to plural control subjects in accordance with the control type signals. CONSTITUTION:A storage means 4 stores plural pieces of expected value of the input/output signals corresponding to the control subjects 1a and 1b in accordance with the control type signals. A discrimination means 5 discriminates the types of subjects 1a and 1b with input of the control type signal, and at the same time a selection means 6 selects the expected value corresponding to both subjects 1a and 1b out of the means 4. A detection means 7 compares the selected expected value with the value of the input/output signal monitored by a monitor means 3. Thus a trouble of the control subject is detected. As a result, it is possible to automatically cope with the change of the control subject became the data on the expected value can be switched in accordance with plural control subjects.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an external failure detection device for a control device, and particularly to an external failure detection device that can operate control and failure detection in synchronization.

(Prior Art) Fig. 5 shows a conventional external fault detection device of this type, in which (51) is an input/output circuit section, (52) is a control section, and (53) is a fault detection section. , (54) is the expected value storage unit, (
55) is a display device, and (56) is a controlled object for which failure detection is performed.

FIG. 6 shows the data structure of the expected value stored in the expected value storage section (54). In the figure, (61) is the expected value, and the symbols (61a), (Blb), (61
c) A plurality of them are prepared as shown by "s" (61n).

FIG. 7 is a flowchart showing the processing procedure of the failure detection section (53) of FIG. 5, and the operation of the conventional device will be explained below with reference to this flowchart.

The control section (52) controls the controlled object (56) via the input/output circuit section (51), and at this time the failure detection section (53) performs the following processing.

First, in step (71), input/output data is taken in, and in step (72), the expected value (6
Incorporate 1). Then, in step (73),
It is determined whether the input/output data and the expected value (61) match. If they match, proceed to step (74);
After moving the pointer of expected value (61) to (61b),
Return to step (71). If they do not match, the process proceeds to step (75), where it is determined that a failure has occurred and the display (5)
5) Displays the details of the failure.

[Problem to be solved by the invention]

Since the conventional external failure detection device is configured as described above, there is a problem in that when the controlled object (56) changes, the content of the expected value (61) must be changed.

Therefore, some devices have been proposed that are capable of detecting failures in multiple controlled objects, as shown in Japanese Patent Application Laid-Open No. 61-813, for example. There are problems such as not being able to operate the

This invention was made to solve the above problem, and is capable of detecting a failure in a controlled object by automatically changing the expected value according to a change in the controlled object, and also synchronizes control and failure detection. The object of the present invention is to obtain an external failure detection device that can be operated as described above.

[Means to solve the problem]

The external failure detection device according to the present invention includes a control means for controlling a plurality of control objects, a monitor means for monitoring input and output signals of each control object including a control type signal, and a monitor means for monitoring input and output signals of each control object including a control type signal. a storage means for storing a plurality of expected values in correspondence with each of the control type signals; a determining means for determining the type of the controlled object for each scan of the control program by inputting the control type signal; and a determined control. a selection means for selecting an expected value corresponding to the type of object from the storage means; and a detection means for detecting a failure by comparing the selected expected value with the value of the input/output signal monitored by the monitoring means. It is designed to provide one for each.

(Operation) In the present invention, a plurality of expected values corresponding to each of a plurality of control objects are stored in correspondence with a control type signal, and a control type signal from each control object is stored for each scan of a control program. An expected value corresponding to the controlled object is automatically selected by checking, and a failure is detected by comparing this expected value with the monitored value of the input/output signal of the controlled object.

〔Example〕

FIG. 1 is an overall configuration diagram showing an embodiment of an external failure detection device according to the present invention. As is clear from FIG. 1, this embodiment has a plurality of control objects (la), (lb)
a control means (2) for controlling the input/output signals of each controlled object (la) and (lb), a monitoring means (3) for monitoring the input/output signals of each controlled object including the control type signal, and a plurality of input/output signals corresponding to each controlled object (la) and (lb). Storage means (4) are provided for storing expected values in correspondence with each control type signal, and in the determining means (5), one of the control programs is determined by inputting the control type signal.
The types of controlled objects (la) and (lb) are determined for each scan, and the expected values corresponding to the types of controlled objects (la) and (1'b) determined by the selection means (6) are stored in the above-mentioned memory. A failure is detected by comparing the selected expected value from the means (4) with the value of the input/output signal monitored by the monitor means (3) in the detecting means (7), and detecting the details of the detected failure. is configured to be displayed on the display means (8).

FIG. 2 shows the hardware configuration of the external failure detection device of the embodiment shown in FIG. Data storage section, (23) is failure detection section, (24) is expected value storage section, (
25) is a display, (26) and (27) are control type signals, (28) is the controlled object 1 controlled by the control unit (21) via the input/output circuit unit (20), and (29) is the same. This is the second controlled object.

FIG. 3 shows the structure of a plurality of expected value data stored in the expected value storage section (24).
) is a control type signal value, which includes a type signal value (30a) corresponding to the above control type signal (26) and a control type signal (27).
! , :corresponding type signal value (30b). (31) is the expected value 1 stored in association with the type signal value (30a), and has the symbol (31a).

A plurality of them are prepared as shown in (31b), -..., (31n). (32) is the above type signal value (3
The expected value 2 is stored in association with 0b), and the sign (
32a), (32b).

..., a plurality of them are prepared as shown in (32n).

FIG. 4 is a flowchart showing the processing in the failure detection section (23) of FIG. 2, and the operation of this embodiment will be explained below with reference to this flowchart.

The control section (21) controls the controlled object 1 (28) or the controlled object 2 (29) via the input/output circuit section (20), and outputs input/output data to the input/output data storage section (22). At this time, the failure detection section (23) operates as follows. That is, first, in step (40), wait until all input/output data is set in the input/output data storage section (20), and then in step (41), input/output data is taken in. Next, in step (42), control type signals (26) and (27) are checked.

Then, the value of the control type signal (26) is changed to the type signal value (30
a) If it matches, the process proceeds from step (43) to step (44), and if the value of the control type signal (27) matches the type signal value (30b), the process proceeds from step (43) to step (47). .

In step (44), data (31a) of expected value 1 (31) is fetched, and in step (45), it is determined whether or not it matches the input/output data. If they match, in step (46), the pointer of expected value 1 (31) is shifted to data (31b), and then the process returns to step (40).

On the other hand, in step (47), the expected value 2 (32
) is taken in, and in step (48) it is determined whether it matches the input/output data.

If they match, in step (49), the pointer of expected value 2 [2] is shifted to data (32b), and then the process returns to step (40).

Furthermore, if it is determined that they do not match in step (45) and step (48), then step (50) is performed.
), it is determined that a failure has occurred, and the process is terminated after being displayed on the display (25).

In addition, although the said Example showed the case where there were two control objects, there is no restriction|limiting in the number. In addition, the expected value data corresponding to the controlled object does not have to be one-to-one with the controlled object, and if there is one expected value for multiple controlled objects, the value should be the same as the control type signal. A similar effect can be obtained.

〔Effect of the invention〕

As explained above, in this invention, the expected value data can be switched in correspondence with multiple control objects, so automatic fishing can be applied to changes in the control objects, and synchronized with one scan of the control program. Therefore, there are effects such as being able to operate control and failure detection in synchronization.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of an external failure detection device showing an embodiment of the present invention, Fig. 2 is a hardware configuration diagram thereof, Fig. 3 is an explanatory diagram showing the structure of expected value data, and Fig. 4 is a failure detection device. A flowchart showing the detection operation, FIG. 5 is a diagram equivalent to FIG. 2 showing a conventional external fault detection device, FIG. 6 is an explanatory diagram showing the structure of expected value data in the conventional device, and FIG. 7 is a diagram showing the structure of expected value data in the conventional device. 3 is a flowchart showing a detection operation. (la), (lb)...Controlled object, (2)...
Control means, (3)...Monitoring means, (4)...Storage means, (5)...Discrimination means, (6)...Selection means,
(7)...detection means, (8)...display means. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A control means for controlling a plurality of control objects, a monitor means for monitoring input and output signals of each control object including a control type signal, and a plurality of expected values of input and output signals corresponding to each control object,
a storage means for storing the signals in correspondence with each of the control type signals;
a determining means for determining the type of the controlled object for each scan of the control program by inputting a control type signal; a selecting means for selecting an expected value corresponding to the determined type of the controlled object from the storage means; 1. An external failure detection device comprising: a detection means for detecting a failure by comparing the expected value determined by the input/output signal with the value of the input/output signal monitored by the monitor means.