JPS63257802A - Device for diagnosing failure of external apparatus for programmable controller - Google Patents

Abstract

PURPOSE:To rapidly and accurately process the failures of actuators by monitoring the operation of these actuators by means of an alarm unit including an arithmetic part and a storage part when a programming tool to which a user program is inputted drives the plural actuators. CONSTITUTION:The programming tool 1 including a user program, a CPU unit 2, plural I/O units 3 for controlling the actuators 6, and the alarm unit 4 are connected to one system bus 5. Each I/O unit 3 is provided with a sensor 7 and the unit 4 for diagnosing failures and generating an alarm at the time of detecting abnormality is constituted of the arithmetic part 41 consisting of a microprocessor, the storage part 42 consisting of a RAM, a clock part 43 consisting of a reference clock generator and a counter, a display part 44 for informating a failure, a mode switching operation part 45, and an interface 46.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for diagnosing faults in an external device connected to and controlled by a programmable controller that processes a user program in the form of a flowchart.

(Summary of the Invention) In the present invention, a conditional branch instruction and a pattern in which its input condition should change are extracted from a user program in a flowchart format processed by a programmable controller, and the stored conditional branch instructions are stored in correspondence with each other. When the command is executed, the time until the input condition changes is learned using the stored pattern corresponding to the command.

When a predetermined mode is selected, it is determined whether the actual measurement time is longer than the learned measurement time, and if the actual measurement time is longer than the learning measurement time, the The occurrence of a failure in the external device that determines the time input conditions is notified.

(Background of the Invention) External equipment connected to a programmable controller is sequence-controlled by the programmable controller according to a user program, but if a failure occurs during use, the equipment must be maintained or its parts replaced.

However, in the past, it took a lot of effort and time to discover failures in external equipment, and therefore there was a demand for labor saving in system management.

(Object of the invention) The present invention has been made in view of the above-mentioned conventional problems, and
The purpose is to provide a device that can automatically warn of the occurrence of a failure in external equipment controlled by a programmable controller according to a user program in the form of a flowchart.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention provides a program data extraction means for extracting a conditional branch instruction and an input condition change pattern at the time of execution of the instruction from a user program in a flowchart format; extracted data storage means for storing a conditional branch instruction and an input condition change pattern in correspondence with each other;
a timer for measuring the time until an input condition changes according to a pattern stored in a memory corresponding to the instruction when a conditional branch instruction stored in the storage section is executed; measurement time learning means for storing the measurement time using the learned measurement time; measurement time monitoring means for determining whether the actual measurement time is longer than the learned measurement time when a predetermined mode is selected; The present invention is characterized by comprising a failure notification means for notifying the occurrence of a failure in an external device that determines input conditions for the measurement time when the actual measurement time is longer than the measurement time.

According to the present invention, a conditional branch instruction, an input condition change pattern at the time of execution of the instruction, and the time required for the change are automatically determined in advance, and the input condition changes within a predetermined pattern within the time when the conditional branch instruction is executed. The occurrence of a failure in an external device is automatically notified to the outside when there is no change, and the occurrence of a failure in an external device can be automatically determined and notified without incorporating a special program into the user program in the form of a flowchart. It becomes possible to quickly, accurately, and extremely easily take measures against the occurrence of a failure in external equipment without incurring any burden.

(Description of Embodiments) Hereinafter, preferred embodiments of the apparatus according to the present invention will be described based on the drawings.

In FIG. 1, programming tool 1. CPU unit 2. I10 unit 3..., alarm unit 4 are connected to system bus 5, and I10 unit 3...
・Various actuators 6 (external devices) and sensors 7
are connected to each other.

A user program in the form of a flowchart is input from the programming tool 1, and the user program is executed by the CPU unit 2.

At that time, the detection signal of each sensor 7 is
The control signals obtained through the processing of the user program are sent to each actuator 6 via the I10 unit.

Failure diagnosis of these actuators 6 is performed by a diagnostic unit 4, whose block configuration is shown in FIG.

In the figure, the diagnostic unit 4 includes an arithmetic unit 41. Storage unit 42 configured with RAM. A timekeeping section 43 consisting of a reference clock generator, a counter, etc. A display unit 44 for notifying the failure of the actuator 6. Operation unit 4 for inputting mode switching commands, etc.
5, and the arithmetic unit 41 exchanges data with the CPU unit 2 via the interface 46 and the system bus 5.

FIG. 3 shows a general processing procedure performed by the calculation unit 41. When a mode command is received from the operation unit 45 in the operation unit service process (step 300), the commanded mode is changed to the teaching mode. It is determined whether or not (step 30
1).

When the commanded mode is the teaching mode (YES at step 301), teaching processing (step 302) is performed, and when the commanded mode is not the teaching mode (NO at step 301),
If the diagnostic mode is activated (YES in step 303), a diagnostic process (step 304) is performed.

FIG. 4 shows the procedure of the teaching process. First, it is determined whether or not the address table shown in FIG. 5 is being edited (step 400).

When it is confirmed that the address table is not being edited (NO in step 400), the creation is completed by the operation section 45.
It is determined whether the command has been issued (step 40).
1) When the command input is confirmed, step 401
(YES), an address table is created (step 402).

Further, when an address table creation command is not input (No in step 401), it is determined whether an address table editing command has been input (step 401).
3) When the command input for editing the 7-address table is confirmed (YES at step 403), a flag indicating that the address table is being edited is set (step 404).

When this flag is set to 1~ or when its setting is confirmed (YES at step 400), the address table is edited (step 405), and when the completion of the editing is confirmed (step 406) YES),
The mth flag is reset (step 407).

The above teaching process (step 302) is carried out by the CPU unit 2.
This is executed when the user program of flowchart 1~ format is being executed, and as shown in Figure 6, the CPU unit 2 executes a conditional branch instruction that determines the next step to be executed based on the input condition. Sometimes (Step 6
00: YES), conditional branch instruction processing (step 601)
The address and input conditions of this conditional branch instruction are stored before <Steps 602 and 603>.

The address and input condition of the conditional branch instruction are sequentially fetched into the diagnostic unit 4 at regular intervals as shown in FIG. 7 during address table creation (step 402), and the address is stored in the address table as shown in FIG. is stored in area 42a.

In editing the address table (step 405), flag data indicating the change pattern of each input condition is stored in area 42b in FIG.

In addition, in the condition flag area 42b, flags are set for each pattern of whether diagnosis is performed when the input condition of the conditional branch instruction changes in a pattern from "0" to "1" or vice versa. Diagnosis using both patterns is performed by setting both flags.

When the necessary data is extracted from the flowchart 1-format user program and stored as described above, the diagnostic mode is selected (YES in step 303 in Figure 3).
, the diagnostic process (step 304) of FIG. 8 is started.

In this process, it is first determined whether or not the diagnosis is in actual operation (step 800), and when it is not in actual operation and a command to start it has not been input (step 80).
1 (No), it is determined whether or not the measurement time is being preset (step 802).

At this time, if it is confirmed that the measurement time is not being preset (No in step 802), it is determined whether there is an input to command the start of measurement time presetting (step 803), and the command input is confirmed. (YES in step 803), a flag indicating that presetting is in progress is set (step 804).

The area 42a in FIG. 5 determines whether the instruction currently being executed by the CPU unit 2 is a conditional branch instruction.
(step 805),
If the instruction being executed is not a conditional branch instruction, the address of area 42c shown in FIG. 5 is updated (step 806).

Furthermore, if it is confirmed from the memory address in area 42a that the instruction being executed is executed by any conditional branch instruction (match in step 805), the pattern of the flag stored in area 42b is input accordingly. It is determined whether or not the conditions have changed (step 807), and if no change in the input conditions for that pattern is confirmed (NO in step 807), time data indicating the elapsed time since the execution of the command is displayed in the current area 42c. written to the address (step 808);
This address is updated (step 806). Hey,
As shown in Figure 5, the time data is rOJ → rIJ, MJ →
It is divided into ○ patterns and occupied.

Then, when the input condition change of the memory pattern is confirmed (YES in step 807), the address of area 42G is updated (step 806), and until one-time processing of the user program is confirmed (while NO in step 809),
The above processing (steps 805 to 808) is repeated (time preset).

As a result, the elapsed time from the execution of each conditional branch instruction until its input condition changes in a regular pattern is sampled and sequentially written to consecutive addresses, which causes each conditional branch instruction and its manual conditions to change. The time until the pattern changes corresponding to the regular pattern to be changed is learned (time preset).

Thereafter, the user program is processed once and confirmed (YES in steps 809 and 810).
A flag indicating that the time is being preset is reset (step 8] 1).

With this reset, the teaching process (step 302) is automatically started again, and editing for area 42C in FIG. 5 is started (step 405 in FIG. 4).

At that time, the actuator 46 that does not require failure notification is designated by the manual operation of the operating unit 45, and the flag in the area 42b corresponding to the storage address of the conditional branch instruction regarding the designated actuator 6 is reset.

Further, the time data in the area 42c is automatically corrected, and thereby the preset measurement time is multiplied by a certain amount or extended by a certain period of time. Note that these times can be forcibly changed by operation input from the operation unit 45 as necessary.

When this editing is completed, the diagnostic mode is designated (YES at step 303), and the process shown in FIG. 8 is started.

At that time, the start of the actual diagnostic operation is commanded (step 80).
1: YES), thereby setting a flag indicating that the actual diagnosis is in progress (step 8] 2).

Next, the address of the instruction currently being executed by the CPU unit 2 and each address of the area 42a (see FIG. 5) are compared (step 813), and when it is confirmed that the atrus matches, the corresponding flag of the area 42b is set. When the flag is set (YES in step 813), a change in the manual condition of the normal pattern indicated by the flag in the area 42b corresponding to the address of the conditional branch instruction is monitored (step 8]4).

If the change is not recognized (No in step 814)
The current address in area 42d in FIG. 5 is updated with a count value indicating the elapsed time since the execution of the conditional branch instruction (step 815), and a change in the input condition of the regular pattern is confirmed. When this happens (YES in step 814), this count is reset (step 816).

The above processing (steps 813 to 815) is repeated until one processing of the user program is completed, and as a result,
A count value indicating the elapsed time is written in the area 42d in FIG. 5, similar to the time data in the case of time presetting.

Thereafter, when it is confirmed that the execution of one batch of the user program has been completed (YES in step 817), the counter is updated (step 818), and then the count 1 shift, which exceeds the time indicated by the preset data, is placed in the area 42.
d (step 819).

When the abnormal count value is searched (YES in step 819), an input command is issued using the addresses and flags of areas 42a and 42b.

The conditional branch instruction and information indicating a failure of the actuator 6 are executed and displayed on the display unit 44 (step 820
．． 821>.

Note that when an instruction is given to stop the diagnosis (Y in step 822)
A flag indicating that diagnosis is in progress is set in ES) (step 823), and this process ends.

Further, the data (for example, 50) that determines the reception interval of the input condition (for example, 2Qmsec) is automatically preset according to the time at which the input condition is received (for example, 1 second), and the operation unit 45 is operated as necessary. will be corrected.

As explained above, according to this embodiment, it is possible to automatically notify the occurrence of a failure in each actuator 6 without incorporating a special program into the user program. It becomes possible to quickly, accurately, and extremely easily take measures against the occurrence of a failure in each actuator 6 without causing any problems.

[Brief explanation of the drawing]

FIG. 1 is an overall block diagram showing an example of a system to which the present invention is applied, and FIG. 2 is a diagram showing one of the diagnostic units shown in FIG. 1.
FIGS. 3 and 4 are flowcharts 1 to 4 showing the processing procedure performed in the arithmetic section of FIG. 2, and FIG. FIG. 6 is an explanatory diagram of the contents of the instruction executed by the CPU unit shown in FIG. 1. FIG. 8
The figure is a flowchart explaining the processing contents of the arithmetic unit in FIG. 2. 10... Programming tool 2... CPU units 1 to 3... I10 unit 4... Diagnosis unit 5... Actuator 6... Sensor 41...Calculation unit 42...Storage unit 43...Timekeeping unit 44...Display unit 45...Operation unit 46...Interface Patent applicant Tateishi Electric Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 6 Figure 7

Claims (1)

[Claims] (1) Program data extraction means for extracting a conditional branch instruction and an input condition change pattern at the time of execution of the instruction from a user program in a flowchart format, and storing the extracted conditional branch instruction and input condition change pattern in correspondence. Extracted data storage means; Timing means for measuring the time until an input condition changes according to a stored pattern corresponding to the stored conditional branch instruction when the stored conditional branch instruction is executed; and the stored conditional branch instruction and input. Measurement time learning means for storing measurement times in correspondence with condition change patterns; Measurement time for determining whether the actual measurement time is longer than the learned measurement time when a predetermined mode is selected. The device is characterized by comprising: a monitoring means; and a failure notification means for notifying the occurrence of a failure in an external device that determines the input conditions for the measurement time when the actual measurement time is longer than the learned measurement time. Failure diagnosis device for external equipment for programmable controllers.