Troubleshooting Of The Master Station; The Run Led Does Not Turn On; The L Run Led Does Not Turn On - Mitsubishi Melsec-L Series User Manual

8.3

Troubleshooting of the Master Station

This section describes troubleshooting of the master station.
8.3.1

The RUN LED does not turn on

Check the following:
The module is incorrectly connected.
The internal current consumption of the entire system
exceeds the rated output current of the power supply
module.
If the RUN LED does not turn on even after the above actions are taken, the possible cause is a hardware failure.
Please consult your local Mitsubishi service center or representative, explaining a detailed description of the problem.
8.3.2

The L RUN LED does not turn on

Check the following:
The CPU module has just exited from reset status.
The test mode switch is on.
Data link stop (bit 0) of Data link stop/restart instruction
(buffer memory address: 19 (Un/G19)) is on.
The number of occupied I/O points set using the switch
exceeds the number of occupied I/O points of the CPU
module.
*1 When Data link stop and Data link restart are simultaneously turned on, the instruction of Data link stop takes priority.
Turn off Data link stop before turning on Data link restart.
If the L RUN LED does not turn on even after the above actions are taken, the possible cause is a hardware failure.
Please consult your local Mitsubishi service center or representative, explaining a detailed description of the problem.
Check item
Check item
CHAPTER 8 TROUBLESHOOTING
Action
Disconnect the module and connect it again.
Change the system configuration so that the internal current
consumption may be within the rated output current.
For how to calculate current consumption of the entire
system, refer to the following.
MELSEC-L CPU Module User's Manual (Hardware
Design, Maintenance and Inspection)
Action
It takes time for the L RUN LED to turn on after the CPU
module exits from reset status. Wait for a while.
• When the L ERR. LED is on, troubleshoot with reference
to the following.
( Page 57, Section 8.3.4)
• When the L ERR. LED is not on, please consult your local
Mitsubishi service center or representative, explaining a
detailed description of the problem.
Turn off the Data link stop then turn on Data link restart (bit
*1
15).
Correct the setting then power off and on the system or reset
the CPU module.
( Page 15, CHAPTER 2)
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