JPH0264706A - Pc condition analyzing system - Google Patents

Abstract

PURPOSE:To easily find a cause when the debug or alarm of the sequence program of a programmable controller (PC) occurs by displaying an external input signal which contributes to the output condition of an arbitrary coil. CONSTITUTION:A CPU 1 controls the whole PC, a ROM 2 stores a system program 4 and a condition analyzing system is programmed. A key-in is executed from a keyboard to display the cause of the ON/OFF of the output coil and the display of the cause is requested. The coil designated by the display request is searched, its lang is confirmed, a relay used by decoding is confirmed, further its lang is analyzed and the relay which causes the ON/OFF of the output coil is decided. Next, it is decided whether the decided relay is the external input signal or an internal relay, and when it is the internal relay, it is returned to the coil search and the above operation is repeated. When it is the external input signal, all the relays are displayed on a display 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a programmable controller (hereinafter referred to as a PC), and particularly to a condition analysis method for a PC that analyzes and displays a sequence program.

[Conventional technology]

When debugging a sequence program or investigating the cause of an alarm that has occurred, you may want to know what is causing a particular output coil to turn on or off.

In conventional PCs, in order to know the reason why such an output coil is turned on or off, the operator has to refer to the continuity state display of the sequence program and make a judgment.

[Problem to be solved by the invention]

However, when a sequence program is complex, it is very difficult to analyze the program.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a PC that allows easy investigation of the cause of alarm occurrence and easy debugging.

[Means to solve the problem]

In order to solve the above problems, the present invention includes a first step of searching for a specified coil in a sequence program and confirming the rung to which the coil belongs, and decoding the confirmed rung and decoding the rung to which the coil belongs. a second step of confirming the relay being used; a third step of analyzing the rung with the confirmed state of the relay to determine the relay contributing to the output state of the coil; Determine whether the relay determined in step 3 is an external input signal,
If not, a fourth step of returning to the first step; and a fifth step of displaying the relay that was confirmed to be an external input signal in the fourth step. A condition analysis method for a PC is provided.

[Effect]

Once the output coil and its polarity (on or off) are specified, the system program first searches for the specified coil in the sequence program.

Next, the rung, or net, to which the indicated coil belongs is decoded, and the relays (logical contacts) used in that rung are determined.

Next, the rung is analyzed by comparing the status and connection status of the relays (logical contacts) used to determine which relay is causing the specified coil to turn on or off. If this determined relay is an external input signal, it will be displayed immediately. If this determined relay is only a logical contact point of an internal relay, the coil of the internal relay is searched and the series of processes described above are repeated any number of times until an external input signal is obtained. The external input signal finally obtained in this way is displayed on the display device as the genuine cause.

〔Example〕

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

FIG. 1 shows a block diagram of hardware for implementing the PC condition analysis method according to the present invention.

In the figure, 1 is a processor for controlling the entire PC, 2 is a ROM, and 3 is a RAM. The ROM 2 stores a system program 4, and the system program 4 is programmed with the condition analysis method of the present invention. 5 is a sequence program created by the user, 6
are internal relays used by the user program 5, and both are stored in the RAM 3.

7 is a CRT display device, and 8 is a keyboard for inputting requests for cause display, etc.

An input circuit 9 receives an external input signal, converts the signal level, and transfers it to the bus 10. 11 is an output circuit, which outputs an internal output signal to the outside.

FIG. 2 shows a flow chart of the present invention. The number following S is the step number.

(31) If there is a request to display the cause of on/off of the output coil, the process advances to S2; if there is no request, the process goes to END.

[S2] Search for the output coil specified in the display request,
Check the rung (net) to which the designated coil belongs.

(33) Decode the rung confirmed in S2 and confirm the relay (logical contact) used.

(34) Analyze the rung using the state of the relay confirmed in 33, and determine which relay (logical contact) is responsible for turning on or off the specified output coil.

(35) Determine whether the relay (logical contact) determined in step 34 is an external input signal (DI) or a logical contact of an internal relay.

If it turns out that it is not an external input signal (DI), that is, it turns out that it is only a logical contact of the internal relay, return the coil of the internal relay to S2,
The processes from S2 to S35 are repeated.

Further, if it is determined that the signal is an external input signal (DI), the process advances to S6.

(S6) All relays that were confirmed to be external input signals in S5 are displayed on the display device.

FIG. 3 shows two rungs, rung 1 and rung 2, showing an example of a ladder diagram for explaining the present invention.

The r+XLEJ logic contact is closed when the machine's Y-axis positive limit switch, controlled by the PC, detects an error and is activated. r-XLEJ is Y
Closed when a negative axis limit error is detected.

rXLE is the Y-axis limit error. rYLE is the Y-axis limit error.
Axis limit error and ZLE are internal relays that each indicate a Y-axis limit error, and if any one of the contacts closes, the rLEJ coil, an output coil that means error detection by a limit switch, is activated. produces an output.

Assume now that the "LE" alarm is turned on. If it is desired to display the cause, the user inputs "rLE" and "rON" from the keyboard 8 to instruct display of the cause.

The system program then becomes the user program (
Sequence program), search for LE, and
Check rung 2 to which the E coil belongs. Next, rung 2
Decode and confirm that the three logical contacts of XLESYLE and ZLE are connected in parallel.

Next, the configuration of the rung and the state of each contact are analyzed, and the LE
It is determined that the cause of turning on the coil is XLE.

Next, a search is made to see if that XLE is an output coil in another rung. The XLE contact is an internal relay that returns the XLE coil to 32 in FIG. 2 and repeats the same process as with the designated coil. That is, rung 1 is decoded and it is confirmed that the +XLE contact and the -XLE contact are connected in parallel. Next, rung 1 is analyzed and it is determined that it is the +XLE contact that turns on the XLE coil. Since the +XLE contact is an external input signal, r+XLE is displayed as the reason for turning on the LE coil.

FIG. 4 shows an example of a display on the screen of the display device 7. First, the output coil rLEJ specified in the cause display request.
is displayed as the “designated coil”. Next, r+XLEJ, which caused the specified coil to turn on, is displayed as "r ON condition relay". The internal relay rXLEJ, which became clear at an intermediate stage of the process, is then displayed as an "internal condition relay."

In this embodiment, a simple ladder diagram was used as an example for explanation, so there was only one on-condition relay. but,
In a ladder diagram in which many logical contacts are connected in series, there will be a plurality of on-condition relays or off-condition relays.

〔Effect of the invention〕

As explained above, in the present invention, external input signals contributing to the output state of any output coil are displayed, making it easier to debug a PC sequence program and investigate the cause when an alarm occurs. Become.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of hardware for implementing the PC condition analysis method according to the present invention, FIG. 2 is a flowchart of the present invention, FIG. 3 is a ladder diagram used to explain the present invention, and FIG. The figure is a diagram showing an example of a display on a screen of a display device. 1...--Processor 2---
......--ROM 3---1---RAM 4---System program 5--
・・−・−・・−・・−User program 6・−・・
−・−・・・−・Internal 'J t' −7−・・−・・−
・−・・−・Display device 8・・・・・−・−・・・・・・・
Keyboard 9 - Input circuit 0
−・−・・−−−−−−−Bus 1−・−−−−−・−・−・−・Output circuit patent applicant FANUC Co., Ltd. agent Patent attorney Takeshi Hattori #I2 Figure Figure 4

Claims (1)

[Claims] (1) A first step of searching for a specified coil in a sequence program and confirming the rung to which the coil belongs; and a second step of decoding the identified rung and confirming the relay used in the rung. a third step of analyzing the rung using the confirmed state of the relay to determine which relay contributes to the output state of the coil; a fourth step in which the relay determines whether the signal is an external input signal, and if not, the process returns to the first step; and the relay is confirmed to be an external input signal in the fourth step. A PC condition analysis method comprising: a fifth step of displaying;