Verifying Errors From Led Status - Mitsubishi Electric MELSEC QS SERIES User Manual

9
TROUBLESHOOTING

9.3 Verifying Errors from LED Status

The following table lists causes and corrective actions for errors indicated by LEDs on the
safety remote I/O module when the network parameters are properly set and also the
"MST" LED of the safety master module is on (i.e. under data link control) in the system
configuration example shown below.
LED status
Safety Safety remote I/O module
master
A
module
POWER
L RUN
L ERR.
POWER
L RUN
ERR.
L ERR.
or
POWER
ERR.
L RUN
L ERR.
POWER
L RUN
L ERR.
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- 12 9.3 Verifying Errors from LED Status
Station No.1
Figure 9.8 Configuration example for error verification
Table9.1 Verifying errors from LED status
B C
POWER POWER
L RUN L RUN
L ERR. L ERR.
POWER POWER
Since the LEDs on the safety remote
I/O module are all off, the 24V power is
L RUN L RUN
not supplied or voltage is low.
L ERR. L ERR.
The safety remote I/O module A is
POWER POWER
malfunctioning and the LEDs are
L RUN L RUN
unstable(all lights are off, in many
L ERR. L ERR.
cases).
POWER POWER
The transmission cable is shorted.
L RUN L RUN
The transmission cable is wired
L ERR. L ERR.
incorrectly.
Module A Station No.2
Cause
Normal
Module B Station No.3
Corrective action
-
Check the voltage of the 24V power
supply, and supply the proper power to
the safety remote I/O module.
Replace the safety remote I/O module.
Find the shorted cable among the three
transmission cables and repair it.
Verify wiring in the terminal box of the
safety remote I/O module and correct.
: On, : Off, : On, flashing, or off
Module C