The L Err. Led Is On Or Flashing - Mitsubishi Melsec-L Series User Manual

8.3.4

The L ERR. LED is on or flashing

Check the following:
(1) The L ERR. LED is on
The test mode switch is on.
A remote station is connected outside the control range.
A faulty remote station is detected by Faulty station
information (buffer memory address: 4 to 7 (Un/G4 to 7)).
( Page 68, Appendix 1)
A communication cable is incorrectly wired.
*1 Check for short circuit, reverse connection, disconnection, excessive pressure, terminating resistors, overall cable
distance, branch line distance (overall branch line length, maximum branch line length), and surrounding environment
such as a noise.
If the L ERR. LED remains 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
CHAPTER 8 TROUBLESHOOTING
Action
Please consult your local Mitsubishi service center or
representative, explaining a detailed description of the
problem.
Remove the remote station connected outside the control
range.
Increase the number of occupied I/O points.
Set a greater value for the last station number.
After taking the above actions, power off and on the system
or reset the CPU module.
Troubleshoot the faulty remote station.
Remote I/O station: Page 59, Section 8.4
Remote device station
User's manual for the remote device station used
*1
Correct the wiring.
( Page 36, Section 6.3)
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