Mitsubishi Electric MELSEC Q Series User Manual page 71

(2) The L ERR. LED is flashing
Error (all stations) (bit 1) of Detailed error information (buffer
memory address: 16 (Un/G16)) is not on.
A 24VDC supply voltage is outside the specified range.
A faulty remote station is detected by Faulty station
information (buffer memory address: 4 to 7 (Un/G4 to 7)).
(
A communication cable is incorrectly wired.
*1
*2
If the L ERR. LED remains flashing 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.
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Check item
Page 31, Section 3.3.2)
Measure a voltage using check terminals on the terminating resistor.
Check terminal 24G
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.
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CHAPTER 6 TROUBLESHOOTING
Please consult your local Mitsubishi service center or
representative, explaining a detailed description of the
problem.
Reduce the supply voltage within the specified range.
Troubleshoot the faulty remote station.
Remote I/O station:
Remote device station:
device station used
*2
Correct the wiring.
( Page 49, Section 4.5)
Check terminal 24V
Action
*1
Page 66, Section 6.3
User's manual for the remote
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