JPH07271411A - Fault diagnostic device for programmable controller - Google Patents

Abstract

PURPOSE:To unnecessitate the preparation of a fault diagnostic program due to a user himself, to easily apply the device even to an existent programmable system and to efficiently diagnose a fault without expanding the capacity of a memory for storing input/output patterns. CONSTITUTION:A fault diagnostic unit is connected to a system bus 1 of a PC. In the case of a teaching mode, based on setting due to an operation part 45, the fault diagnostic unit monitors the output pattern on the system bus 1 and stores the passage of time from a preceding change point of time to a change and the input/output pattern after the change in a storage part 42 each time the output pattern is changed. In the case of a diagnostic mode, the output pattern is similarly monitored, and it is judged whether that stored output pattern arrives within monitor time based on the passage of time of the output pattern or not. When that output pattern does not arrive, an unmatching part between the input/output pattern at that point of time and the input/output pattern stored in the teaching mode is displayed on a display part 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosing device suitable for a building block type programmable controller, and more particularly to a special failure diagnosing program on a user program only by newly connecting the failure diagnosing device. The present invention relates to a programmable controller failure diagnosis device capable of diagnosing a system failure without the need to create a.

[0002]

2. Description of the Related Art Conventionally, in a programmable controller of this type, for example, in a fault diagnosis in a programmable controller system, a user himself or herself examines input / output conditions which may occur at the time of failure and incorporates it into a user program. Was taken.

[0003]

However, in the fault diagnosis in such a conventional programmable controller, as described above, the user himself or herself checks beforehand the input / output conditions that may occur at the time of the fault and incorporates this in the user program. Since the method was taken, setting failure conditions,
There is a problem that it is extremely troublesome to add a failure diagnosis program to a user program that requires complicated work such as programming, especially when an already completed user program exists.

The present invention has been made in view of such a problem. In this type of programmable controller, it is not necessary for the user to create a failure diagnosis program, and the existing programmable system can be used. An object of the present invention is to provide a programmable controller failure diagnosis device that can be easily applied and that can efficiently diagnose a programmable controller system failure without enormous memory capacity for storing input / output patterns. And

[0005]

In order to achieve the above object, the present invention provides a mode setting means capable of switching the operation mode between a teaching mode and a diagnostic mode, and an output pattern on the condition that the teaching mode is set. The teaching operation control means for monitoring each of the output patterns, storing the elapsed time from the immediately preceding change time to the change and the input / output pattern after the change for each change of the output pattern, and setting the diagnostic mode as a condition. Within the monitoring time based on the elapsed time from the change time immediately before the output pattern stored in the teaching operation control means to the change. If the output pattern does not arrive within the monitoring time, the input / output pattern at that time and the teaching operation control means are stored. It is characterized in that it comprises a diagnostic operation control means for informing a mismatch portion of the output pattern.

[0006]

According to this structure, the failure diagnosis program is automatically created in response to the setting to the teaching mode.
Further, in response to the setting to the diagnosis mode, the failure diagnosis operation independent of the CPU unit is performed, so that the user does not need to create the failure diagnosis program, and the existing user program is not changed. It enables fault diagnosis in various systems.

Further, since attention is paid to the change in the output pattern of the programmable controller rather than the input pattern, efficient failure diagnosis can be performed without enlarging the capacity of the memory for storing the input / output pattern.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG.
It is a block diagram showing the composition of the whole block type programmable controller.

As shown in FIG. 1, this system has a system bus 1, a CPU unit 2, a plurality of I / O units 3, 3 ...
It is called a "fault diagnosis unit". ) 4 are connected. The power supply unit and others are omitted.

FIG. 2 shows a detailed structure of the failure diagnosis unit 4.

As shown in FIG. 2, the failure diagnosis unit 4 includes
Operation unit 41 mainly composed of a microprocessor
And a storage unit 42 mainly composed of a RAM, and a clock unit 4 mainly composed of a reference clock, a counter and the like.
3, a display unit 44 capable of displaying an input / output corresponding to a failure correlation point and a failure occurrence, and an operation unit 45 equipped with a mode changeover switch, a start switch and the like. Further, the arithmetic unit 41 can be connected to the system bus 1 via the interface 46.

FIG. 3 shows a general flow chart of the operation of the failure diagnosis unit.

As shown in the general flow chart of FIG. 3, the operation of the failure diagnosis unit 4 is performed by setting the mode changeover switch of the operation unit 45 to the teaching mode (Yes at step 300) or to the diagnosis mode. The teaching motion control process (step 302) and the diagnostic motion control process (step 303) are selectively executed according to whether or not (step 301 affirmative).

FIG. 4 shows a detailed processing procedure of the teaching operation control processing of step 302 shown in FIG.

First, as shown in FIG. 4, when the teaching operation control process is started, first, a state of waiting for the activation switch of the operation unit 45 being turned on (activation signal "1") is set (step 400). Negative, 401 negative).

When the start switch is turned on (step 4)
00 affirmative, 402 affirmative), and after resetting the STEP counter to zero (step 403), the input / output patterns I1 to In, O1 to
Register On (step 404), register elapsed time 0 (step 405), and then increment the STEP counter.
After updating by 1 (step 406), a clock for measuring elapsed time is activated (step 407).

At this time, the input / output pattern registration is
This is performed by directly reading the data of the I / O unit 3 into the failure diagnosis unit 4 or by incorporating the input / output information in synchronization with the input / output update operation performed by the CPU unit 2.

Thereafter, the arithmetic unit 41 repeatedly reads the output pattern and waits for the presence or absence of a change (step 400 positive, 402 negative, 408 negative).

In this state, if there is a change in the output pattern, that is, if any one bit of the outputs O1 to On changes (Yes in step 408), the changed input / output in the storage area designated by the STEP counter. After the registration of the pattern (step 409) and the registration of the elapsed time from the previous change point (step 410), the STEP counter is updated by +1 (step 411), and the elapsed time measurement clock is reset from zero. After the activation operation (step 412) is performed, the output pattern change waiting state is again entered (step 400 positive, negative 402, negative 408).

As a result, in each area designated by the STEP counter in the storage unit 42, each time the output pattern changes, the input / output pattern after the change and the elapsed time from the immediately preceding change point are sequentially stored. It will be going.

Next, when the activation switch is turned off in the operation unit 45 (No at step 400, Yes at step 401),
After the input / output pattern is registered in the storage area designated by the STEP counter (step 413) and the elapsed time from the previous change time is registered (step 414), all the registration operations are completed.

Therefore, assuming a user program in which only the inputs 1 and 2 and the output 1 change as shown in FIG. 6, the output 1 changes at the times t1 and t10. As shown in the table, the storage unit 42
In the storage area corresponding to each STEP inside, the changed input / output pattern and the elapsed time are sequentially stored.

Next, when the mode changeover switch is set to the diagnostic mode in the operation section 45, the diagnostic operation control process is started.

FIG. 5 shows a detailed processing procedure of the diagnostic operation control processing of step 303 shown in FIG.

First, as shown in FIG. 5, in the diagnostic operation control process, first, the activation switch is put on standby (No at Step 500, No at Step 501).

When the activation switch is turned on (step 5)
00 affirmative, 502 affirmative) and after resetting the STEP counter to zero (step 503), the diagnostic operation is started.

In this diagnostic operation, first, an operation of setting an input / output pattern registered in the current STEP as a reference pattern (step 504), a value obtained by multiplying the elapsed time registered in the current STEP by a system constant is used as the reference time. As a result, the monitoring timer is started (step 506) after the operation of setting the monitoring timer (step 505) and waits until the current output pattern and the reference output pattern match before the monitoring timer times out (step 506). Step 50
7 negative, 510 negative).

If the match between the current output pattern and the reference output pattern is confirmed (Yes at Step 507) before the monitoring timer times out (No at Step 510), the abnormal output is turned off and the abnormal portion data is cleared. After that (step 508), the STEP counter is updated (step 509), and the above operation is repeated for the next step.

On the other hand, if the match between the current output pattern and the reference output pattern is not confirmed before the time-out of the monitoring timer, it is judged that the system is out of order, and when the time-out of the monitoring timer is reached ( Step 51
0 affirmative), the exclusive OR (EOR) of the current input / output pattern and the reference input / output pattern is taken, and the result is set as abnormal point data (step 511) and displayed with abnormal output ON (step 512). It is displayed on the section 44.

As a result, on the display unit 44, the disagreement portion between the current input / output pattern and the reference input / output pattern is visually notified as a failure correlation portion.

As described above, in this embodiment, the input / output pattern at the time of normal operation is registered as shown in FIG. 7 only by setting the mode changeover switch to the teaching mode and turning on the start switch, and thereafter the mode is set. Only by setting the changeover switch to the diagnostic mode and turning on the start-up switch, it is possible to reliably diagnose the system failure thereafter.

Therefore, according to this embodiment, in response to the setting to the teaching mode, the failure diagnosis program in which the changed input / output pattern is stored is automatically created every time the output pattern is changed. C in response to setting to diagnostic mode
Since the failure diagnosis operation is performed independently of the PU unit, it is not necessary for the user to analyze the input / output conditions at the time of failure and incorporate it into the user program as in the conventional failure diagnosis. It is not necessary to create it, and failure diagnosis in this type of system is possible without changing any existing user program.

Further, in this embodiment, the failure diagnosis unit 4
Since it operates independently of the CPU unit 2, there is no fear of delaying the circuit operation processing operation in the CPU unit 2, and it can be easily applied to an existing building block type programmable controller system. It will be possible.

Further, in this embodiment, since attention is paid to the change of the output pattern, not the input pattern of the programmable controller, efficient failure diagnosis is possible without enlarging the capacity of the memory for storing the input / output pattern. Becomes

This is because when a change in the input pattern is captured and the input / output pattern is sampled, there are various input signal forms of the programmable controller, such as analog input and relay input. The time transition of does not always repeat in the same state every cycle, and it is not possible to store all input / output patterns without fail, or if counter commands etc. are used in the user program, the number of inputs The control such as calculating and using for output is frequently performed every day. In this case, if the change of the input pattern is captured and processed, the number of changes is too large and the input / output pattern is stored. However, in the present invention, attention is paid to the change in the output pattern of the programmable controller. Because it is, because such a problem does not occur.

Further, in the present embodiment, the monitoring time for determining the arrival of the output pattern stored in the teaching mode in the diagnostic operation is the monitoring time from the previous change time of the output pattern in the teach mode to the current change. Since the setting is based on the elapsed time, it is possible to deal with a failure in which the output does not change, and it is possible to diagnose by checking the elapsed time of each output pattern.
It becomes possible to investigate where the problem is in the controller, and it can be used for improving the tact time.

[0037]

As described above, according to the present invention, a failure diagnosis program in which the changed input / output pattern is automatically stored every time the output pattern changes in response to the setting to the teaching mode is created. On the other hand, since the failure diagnosis operation independent of the CPU unit is performed in response to the setting to the diagnosis mode, it becomes unnecessary for the user to create a failure diagnosis program, and without changing any existing user program, Fault diagnosis is possible in this type of system.

Further, in the present invention, since attention is paid to the change in the output pattern, not the input pattern of the programmable controller, efficient failure diagnosis can be performed without enlarging the capacity of the memory for storing the input / output pattern. Become.

Further, in the present invention, the monitoring time when the diagnostic operation control means judges the arrival of the output pattern stored in the teaching operation control means is changed from the change time immediately before the output pattern in the teach mode to the present change time. Since it is set based on the elapsed time up to, it is possible to deal with a failure in which the output does not change, and to diagnose by checking the elapsed time of each output pattern.
It becomes possible to investigate where the problem is in the controller, and it can be used for improving the tact time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire building block type programmable controller system to which the present invention is applied.

FIG. 2 is a block diagram showing details of a failure diagnosis unit.

FIG. 3 is a general flowchart showing processing of a failure diagnosis unit.

FIG. 4 is a flowchart showing details of teaching operation control processing.

FIG. 5 is a flowchart showing details of diagnostic operation control processing.

FIG. 6 is an explanatory diagram showing an example of transition of an input / output pattern.

FIG. 7 is a memory map showing the contents of a storage unit.

[Explanation of symbols]

 1 System Bus 2 CPU Unit 3 I / O Unit 4 Failure Diagnosis Unit 41 Arithmetic Section 42 Storage Section 43 Clock Section 44 Display Section 45 Operation Section 46 Interface

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G05B 23/02 301 P 7531-3H

Claims (1)

[Claims] 1. A mode setting means capable of switching and setting an operation mode between a teaching mode and a diagnostic mode, and monitoring an output pattern under the condition of setting the teaching mode, and changing the output pattern by one before each change. Teaching operation control means for storing the elapsed time from the time point to the change and the input / output pattern after the change, and the output pattern is monitored under the condition of setting to the diagnostic mode, and is stored in the teaching operation control means. It is determined whether or not the output pattern arrives within the monitoring time based on the elapsed time from the immediately preceding change time of the output pattern stored in the teaching operation control means to the change, and the output pattern is monitored as described above. If it does not arrive within the time, the diagnostic operation control hand that notifies the inconsistency of the input / output pattern at that time and the input / output pattern stored in the teaching operation control means. If, programmable controller of the failure diagnosis apparatus characterized by comprising a.