Hitachi HSC-2100, Hardware Manual

Page: 157 / 169

6 MAINTENANCE
6-8
z Case 4 -- all of the input points are turned on and off irregularly:
Check item Remedial action
External input voltage too low
Apply rated input voltage to the digital
input module.
Not the above
Replace the digital input module with a
new one.
z
Case 5 -- a particular input point(s) are not turned off:
Check item Remedial action
External-equipment abnormality Adjust the external equipment.
Not the above
Replace the digital input module with a
new one.
6.2.4 Troubleshooting a digital output module
z Case 1 -- none of the load points is turned on:
Check item Remedial action
Power supply module’s POWER ON LED not lit
Troubleshoot the power supply module
according to the instructions given in
Subsection 6.2.1.
Remote I/O station module’s RI/O LED not lit
Troubleshoot the remote I/O station
module according to the instructions given
in Subsection 6.2.2.
Power not supplied to the load Suppy power to the load.
Applied load voltage other than the rated voltage Apply the rated voltage to the load.
None of the above
Replace the digital input module with a
new one.
z Case 2 -- a particular load point(s) are not turned on:
Check item Remedial action
Operation
indicator
LED
condition
Not
lit
Load’s on-state duration too
short
Correct the program.
Program I/O address error
Lit
External wire breakage Check the external wiring.
Loosened terminal screw Apply additional tightening to the screw.
Incorrect external wiring Corrent the external wiring.
None of the above
Replace the digital input module with a
new one.