Mitsubishi Electric MELSEC-Q Series User Manual page 327

When the test is completed
CPU module Master/local module
MODE
RUN
ERR.
USER
BAT.
BOOT
When the test is not completed
CPU module Master/local module
MODE
RUN
ERR.
USER
BAT.
BOOT
(2) Precautions
(a) Cable connection
Perform a hardware test to a master/local module alone with cables disconnected. Failure to do so may result
in a failure of the test.
(b) CPU module switch
Before performing a hardware test, check that the CPU module is set to STOP.
For operation check of the watchdog timer function, when the hardware test is performed, an error (SP.UNIT
DOWN) occurs and the CPU module stops.
5.
: ON
: Flashing
: OFF
6.
: ON
: Flashing
: OFF
: ON
: Flashing
: OFF
CHAPTER 11 TROUBLESHOOTING
The hardware test starts. During the test, the MST
LED on the master/local module is flashing.
The test is completed in about 30 seconds.
When the hardware test is completed, the MST LED
on the master/local module turns off or on.
• When the test is completed
MST LED on the master/local module: OFF
ERR. LED on the CPU module: Flashing (for
operation check of the watchdog timer function)
• When the test is not completed
MST LED on the master/local module: ON
ERR. LED on the master/local module: Flashing
If the test fails, check if the terminating resistor
provided with the master/local module is connected
between the DA and DB terminals.
If the terminating resistor is connected, the possible
cause is a hardware failure. Replace the master/local
module.
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