Hitachi HSC-2100 Hardware Manual page 158

Case 3 -- none of the load points is turned off:
Remote I/O station module's RI/O LED not lit
LPU or CPU module operation abnormality
None of the above
Case 4 -- a particular load point(s) are not turned off:
Not
lit
Operation
indicator
LED
Lit
condition
None of the above
Case 5 -- all of the load points are turned on and off irregularly:
Applied load voltage other than the rated voltage
Noise reduction measure not taken
Program error
None of the above
Check item
Check item
External-wiring abnormality
Remote I/O station module's
RI/O LED not lit
LPU or CPU module
operation abnormality
Check item
Troubleshoot the remote I/O station
module according to the instructions given
in Subsection 6.2.2.
Refer to the instruction manual on the
LPU or CPU module and troubleshoot it.
Replace the digital output module with a
new one.
Check the external wiring and correct it.
Troubleshoot the remote I/O station
module according to the instructions given
in Subsection 6.2.2.
Refer to the instruction manual on the
LPU or CPU module and troubleshoot it.
Replace the digital output module with a
new one.
Apply the rated voltage to the load.
Install surge killers for the digital output
module and change the cable laying if
necessary.
Correct the program.
Replace the digital output module with a
new one.
6-9
6 MAINTENANCE
Remedial action
Remedial action
Remedial action