Troubleshooting; Troubleshooting Basics - Mitsubishi Electric Melsec-Q172DCPU User Manual

6 INSPECTION AND MAINTENANCE

6.6 Troubleshooting

6.6.1 Troubleshooting basics

This section describes the various types of trouble that occur when the system is
operated, and causes and corrective actions of these troubles.
The basic three points that must be followed in the troubleshooting are as follows.
(1) Visual inspection
Visually check the following.
(a) Movement of machine (stopped condition, operating condition)
(b) Power supply on/off
(c) Status of input/output devices
(d) Installation condition of the Power supply module, Motion CPU module, PLC
CPU module, I/O module, Motion module, intelligent function module,
SSCNET cable, Synchronous encoder cable.
(e) State of wiring (I/O cables, cables)
(f) Display states of various types of indicators
PLC CPU module
Motion CPU module : 7-segment LED (Installation mode, Operation mode,
(g) Status of setting of various types of switches (Setting of No. of stages of
extension base, power interrupt hold-on status).
After checking (a) to (g), monitor the operating conditions of servo motors and
error code using MT Developer2 and GX Works2/GX Developer.
(2) Check of trouble
Check to see how the operating condition varies while the Motion controller is
operated as follows.
(a) Set the RUN/STOP switch of Motion CPU module to STOP.
(b) Reset the trouble with the RUN/STOP/RESET switch of PLC CPU module.
(c) Turn ON and OFF the Multiple CPU system power supply.
(3) Narrowing down the range of trouble occurrence causes
Estimate the troubled part in accordance with items (1) and (2) above.
(a) Multiple CPU system or external devices
(b) Motion CPU or PLC CPU
(c) I/O module or others
(d) Servo program or Motion SFC program/Motion program
(e) Sequence program
: MODE LED, RUN LED, ERR. LED, BAT LED, I/O
LED, etc.
Battery error, STOP/RUN, etc.)
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