JPH03214301A - Fault diagnostic method for numerical controller - Google Patents

Abstract

PURPOSE:To attain the labor saving of a fault recovery work and to shorten its time by storing in advance a ladder program of a PMG (programmable machine controller) in a memory, executing the ladder program by varying an input signal of this ladder program one by one and operating a designated output signal. CONSTITUTION:When a fault is generated in a numerical controller 10 having a PC (programmable controller), which output signal does not operate is designated. Also, an internal signal of the PC is stored in a memory 13 in advance, and in order to specify an input signal for giving a variation to a designated output signal designated previously (that is, the designated output signal is operated), a ladder program is executed. Also, as a means for checking an abnormal input signal, whenever one piece of ladder program input signal is varied, a cycle of the ladder program is executed several times. In the same way, it is executed until the designated output signal operates, and the abnormal input signal is displayed on a fault diagnostic screen. In such a way, the labor saving of a fault recovery work is attained and its time can be shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for diagnosing a failure of a numerical control device, and in particular a method for diagnosing a failure by simulating internal signals of a PC (programmable controller) stored in a memory. The present invention relates to a method for diagnosing a failure of a numerical control device.

[Conventional technology]

In the event of a failure in a numerical control device, in order to identify the location of the failure, a person who is fully familiar with the configuration of the control device and machine should check which output signal did not operate and identify the input related to this output signal. It is necessary to consider each signal one by one. Therefore, excellent technicians are required to quickly repair failures.

[Problem to be solved by the invention]

However, in the conventional failure diagnosis method for numerical control devices, engineers read a ladder program to determine which input signal caused the output signal to malfunction. This method relies heavily on the skill and intuition of the technician, and there are problems in that the time required for repair varies, and the reliability after repair is not perfect.

The present invention has been made in view of these points, and an object of the present invention is to provide a method for diagnosing a failure of a numerical control device by simulating internal signals of a PC stored in a memory.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a fault diagnosis method for a numerical control device having a PC (programmable controller). The PC
By changing the related signals of the lag program in each one,
The ladder program is executed until the specified signal changes, and when the specified signal changes, the changed related signal is displayed on a display screen, and an abnormal signal is detected. , a method for diagnosing a failure of a numerical control device is provided.

[Effect]

In a numerical control device having a PC, specify which output signal does not operate when a failure occurs. Also, PC
The internal signals of are stored in a memory, and a ladder program is executed to specify an input signal that causes a change in the previously designated designated output signal (that is, causes the designated output signal to operate).

As a means for checking abnormal human input signals, the ladder program I is executed several times each time the ladder program input signal changes by one. The process is repeated in the same manner until the specified output signal is activated, and the abnormal input signal is displayed on the failure diagnosis screen.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 4 is a block diagram of the hardware of a numerical control device for implementing the present invention. In the figure, a numerical control device processor 11 controls the entire numerical control device 10. P
The MC (programmable machine controller) processor 12 receives commands such as Mi function, S function, T function, etc., decodes and processes the commands using the ladder program stored in the ladder memory 13, and controls the machine tool 20. An output signal is output from the output circuit 18. It also receives a limit switch signal (human input signal) from the machine tool 20 side or a switch signal (input signal) from the machine operation panel, processes it with a ladder program, and outputs an output signal for controlling the machine tool 20 side.

The state storage memory 14 is a memory that stores all the human output signal data and the like of the execution state of the ladder memory 13.

The graphic control circuit 15 receives the data stored in the state storage memory 14, converts the data into a display signal, and sends it to the display device 16, which displays it. As the display device 16, a CRT, liquid crystal display, or the like is used. The keyboard 17 is used to input various data.

The input/output circuits 18 and 19 input and output input/output signals to and from the machine tool 20 side. That is, the PMC processor 12 receives limit switch signals (input signals) from the machine tool 20 and switch signals (human input signals) from the machine operation panel, and reads them. In the figure, switch 2 is an example of the input signal source.
It represents 2. It also receives an output signal for controlling the pneumatic actuator and the like on the machine tool 20 side from the PMC processor I2 and outputs it to the machine tool 20 side. In the figure, a relay 21 is shown as an example of an object to be controlled by the output signal.

In the above explanation, only the hardware blocks directly related to the present invention are explained, and the ROM memory where the system program is stored and the non-volatile memory where the data that should be saved even after the power is turned off are omitted. .

FIG. 2 is a ladder program for explaining a fault diagnosis method in an embodiment of the present invention. In the figure, the numbers at the left end represent the line numbers of the program, including MOO to MO5 and MO
QC-MO 2C, SPF, SPV, and MFIN represent signal names. In addition, the notes on the right side describe the operation of each line.

As an example, assume that when the machine side is controlled by the M function by executing the ladder program, the M completion (MFIN) output signal (Go.l) does not operate. Address G represents an output signal from the PMC to the numerical controller (NC). A numerical control device (
The state of the input signal MOO, which is the M Isono command from N C ), is inverted. Next, run the ladder program cycles several times. In the same way, change the input signal M O D C and execute ladder program 1.
Execute the ladder program while avoiding changing O1. In this way, the human input signal is sequentially changed, and cycles of the ladder program are executed several times each time. If the ladder program cycle is executed by changing the SPF at line m+3, and if MFIN operates, the abnormal human power signal to be sought is XlO. It is 1. Address X is PM from the machine side
represents the input signal to C. As explained above, the ladder program cycle is executed several times while changing the input signals one by one until the specified output signal is activated, and the human input signal that activated the specified output signal is discovered.

FIG. 3 is a failure diagnosis screen in one embodiment of the present invention. This fault diagnosis screen 1 is a screen selected from the display device 16 of the numerical control device 10 when a fault occurs. When a soft key (for example, a memory transfer key) is pressed, the graphics control circuit 15 converts the data stored in the state storage memory 14 into a display signal and sends it to the display device 16.
displays this as a fault diagnosis screen.

Numerical controller processor 11 and . PMC processor 12
Under the control of the system, when an abnormal human input signal that activates a specified output signal is discovered, related information is displayed on a fault diagnosis screen. A display example is shown below.

Designated output signal MPIN G0.1 Abnormal human power signal SPF X10.1 Designated output signal: Output signal that did not operate at the time of failure MFIN: M completion signal Go. 1: Abnormal output signal from the PMC to the numerical control device Input signal: Input signal that operates the specified output signal SPF: Spindle clockwise rotation signal X10.1: Output signal from the PMC to the machine side Figure 1 (a
) and (b) are flowcharts of a method for diagnosing a failure of a numerical control device according to the present invention. In the figure, the number following S indicates the step number.

[S1] A failure occurs and the output signal does not operate.

[S2] Select a failure diagnosis screen from the display device of the numerical control device.

[53] Press the soft key on the display device fault diagnosis screen,
Ladder program data is transferred from the state storage memory, and the diagnosis status is displayed on the fault diagnosis screen via the graphic control circuit.

[S4] Specify the output signal that will not operate in the event of a failure from the keyboard.

[S5] In order to number the input signals of the ladder program, the first number N is set to 1.

[S6] If input signal of ladder program N=1 is 1, then 0
or, if it is 0, change it to 1.

[S7] Increase the number of the ladder program input signal by 1. N=N+1.

[S8] Execute the ladder program cycle several times.

[S9] Check whether the specified output signal specified in S4 has operated, and if it has not operated, return to S6.

The abnormal input signal that activated the CS10'J designated output signal is displayed on the fault diagnosis screen.

〔Effect of the invention〕

As explained above, in the present invention, PM
Store the C ladder program in memory, change the input signals of this ladder program one by one, run the ladder program, and adjust the specified output signal.
In troubleshooting work for a numerical control device, by automatically identifying the location of the fault, labor and time can be saved in the troubleshooting work.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are flowcharts of the failure diagnosis method for a numerical control device of the present invention, FIG. 2 is a ladder program for explaining the failure diagnosis method in an embodiment of the present invention, and FIG. Fault diagnosis screen in the embodiment. FIG. 4 is a block diagram of the hardware of the numerical control device for implementing the present invention. 1 Failure diagnosis screen 10 Numerical control device 11 0NC processor 12 PMC processor Ladder memory status memory CRT Control device display Keyboard output circuit Input circuit Numerical control device Machine tool relay switch

Claims (2)

[Claims] (1) In a fault diagnosis method for a numerical control device having a PC (programmable controller), when a fault occurs, an internal signal of the PC is stored in a memory, and a ladder program in the PC is associated with a specified designated signal. Execute the ladder program while changing the signals one by one; execute the ladder program until the specified signal changes; and when the specified signal changes, display the changed related signals on the screen. A method for diagnosing failures in numerical control equipment by displaying abnormal signals and diagnosing failures. (2) The PC has a built-in PMC (
2. The method of diagnosing a failure of a numerical control device according to claim 1, wherein the method is a programmable machine controller.