Omron SYSMAC CS Series Operation Manual page 225

Troubleshooting Using LED Indicators
Unit Start up Errors
RUN ERH ERC
Not lit Not lit Not lit
Lit
Lit Not lit
Lit
Lit Not lit Not lit
Lit
Lit ---
204
Probable cause
Power is not being supplied to the CPU
Unit or the power supply voltage is too low.
The CPU Unit or Backplane is faulty.
The mounting screws on the PROFIBUS
Master Unit are loose (CS Series) or the
sliders are not properly locked into place
(CJ Series).
The PROFIBUS Master Unit is faulty.
The PROFIBUS Master Unit is faulty
(COMM LED indicator is also flashing).
The I/O tables are not registered in the
CPU Unit.
The same unit number is being used on
another Unit as well.
The PLC CPU Unit is faulty.
Not a valid combination at startup.
Unit is functionally correct. If there are still problems, check on the other LED indicators.
During startup the checksum of the Error
Log stored in non-volatile memory was
found to be corrupted.
During startup the checksum of the Param-
eter sets stored in non-volatile memory was
found to be corrupted.
During startup the Parameter set stored in
non-volatile memory was correct, but the
contents contains errors preventing the
PROFIBUS interface to be initialized cor-
rectly.
There is an error in the CPU Bus Unit
Setup or routing tables.
Memory in the CPU Unit is faulty.
The CPU Unit is faulty.
A Fatal error occurred in the PLC system.
Note If startup errors prevent the Unit from functioning correctly, the PRM, BST and
BF LED indicators will remain OFF.
Correction
Supply power. Make sure that the correct
voltage is being supplied.
Replace the CPU Unit or the Backplane.
Tighten the mounting screws to the speci-
fied torque (CS Series) or lock the sliders
into place (CJ Series).
Replace the PROFIBUS Master Unit.
Replace the PROFIBUS Master Unit.
Register the I/O tables.
Correct the unit number. Make sure that all
unit numbers used in the system are
unique.
Restart the CPU Unit. If the problem per-
sists, replace the CPU Unit.
Send a ERROR LOG CLEAR FINS com-
mand to the Unit.
Restart the Unit.
Re-download the Parameter sets from CX-
Profibus or the Memory Card.
If the problem persists, replace the PROFI-
BUS Master Unit.
Check the Parameter set in CX-Profibus
and re-download the Parameter sets from
CX-Profibus.
If the problem persists, replace the PROFI-
BUS Master Unit.
Read the error history and correct the data
that is causing the error. If the problem per-
sists, replace the CPU Unit.
Restart the CPU Unit. If the problem per-
sists, replace the CPU Unit.
Restart the CPU Unit. If the problem per-
sists, replace the CPU Unit.
Verify that the PLC CPU and all Units are
working correctly. Restart the CPU Unit. If
the problem persists, replace the CPU Unit.
Section 7-2