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Handling Errors and Alarms Section 4-8
4-8 Handling Errors and Alarms 
4-8-1 Indicators and Error Flowchart
Indicators If an alarm or error occurs in the Analog Output Unit, the ERC or ERH indica-
tors on the front panel of the Unit will light. 
Troubleshooting 
Procedure
Use the following procedure for troubleshooting Analog Output Unit errors.
LED Meaning Indicator Operating status
RUN (green) Operating Lit Operating in normal mode.
Not lit Unit has stopped exchanging data with 
the CPU Unit.
ERC (red) Unit has 
detected an 
error
Lit Alarm has occurred (such as disconnec-
tion detection) or initial settings are incor-
rect.
Not lit Operating normally.
ADJ (yellow) Adjusting Flashing Operating in offset/gain adjustment 
mode.
Not lit Other than the above.
ERH (red) Error in the 
CPU Unit
Lit Error has occurred during data exchange 
with the CPU Unit. 
Not lit Operating normally.
Front panel of Unit
RUN
ERC
ADJ
ERH
Is the ERC indicator 
lit?
Ye s
No
Is the RUN indicator 
lit?
Ye s
No
Alarm has occurred at the Analog Output Unit.
Check whether the initial settings for the Analog Output 
Unit are set correctly. 
Is the ERH indicator 
lit?
Ye s
No
Is the RUN indicator 
lit?
Ye s
No
Error detected by CPU Unit
Check whether the unit number is set correctly. 
Error occurs.
(Refer to 4-8-2 Alarms Occurring at the Analog Output 
Unit.)
(Refer to 4-8-2 Alarms Occurring at the Analog Output 
Unit.)
(Refer to 2-8-3 Errors in the CPU Unit.)
(Refer to 2-8-3 Errors in the CPU Unit.)
Refer to 4-8-5 
Troubleshooting.