Troubleshooting A Digital Output Module - Hitachi HSC-2100 Hardware Manual

6 MAINTENANCE
Case 4 -- all of the input points are turned on and off irregularly:
External input voltage too low
Not the above
Case 5 -- a particular input point(s) are not turned off:
External-equipment abnormality
Not the above

6.2.4 Troubleshooting a digital output module

Case 1 -- none of the load points is turned on:
Power supply module's POWER ON LED not lit
Remote I/O station module's RI/O LED not lit
Power not supplied to the load
Applied load voltage other than the rated voltage
None of the above
Case 2 -- a particular load point(s) are not turned on:
Not
Operation
lit
indicator
LED
condition
Lit
None of the above
Check item
Check item
Check item
Check item
Load's on-state duration too
short
Program I/O address error
External wire breakage
Loosened terminal screw
Incorrect external wiring
Apply rated input voltage to the digital
input module.
Replace the digital input module with a
new one.
Adjust the external equipment.
Replace the digital input module with a
new one.
Troubleshoot the power supply module
according to the instructions given in
Subsection 6.2.1.
Troubleshoot the remote I/O station
module according to the instructions given
in Subsection 6.2.2.
Suppy power to the load.
Apply the rated voltage to the load.
Replace the digital input module with a
new one.
Correct the program.
Check the external wiring.
Apply additional tightening to the screw.
Corrent the external wiring.
Replace the digital input module with a
new one.
6-8
Remedial action
Remedial action
Remedial action
Remedial action