Hitachi NJI-350B - Manual (Page 289)

Chapter 13 Troubleshooting
13-14
The CPU operates, but output signals are not detected.
I/O assignment error occurred, but output is normal.
Replace the expansion cable
Correct the error
YES
NO
Replace the expansion unit
NO
YES
Are the program and
I/O assignment
correct?
Is the expansion unit
cable damaged?
YES
NO
NO
YES
YES
YES
NO
NO
YES
NO
Is there a wiring error,
disconnection or loose
screw on the terminal
block?
Replace the terminal block
Supply 24 VDC power
Contact our service department
Check the program
Perform rewiring
Is the voltage satisfying
the specification in the
terminal block? Is the
polarity correct?
Is the LED lit?
Are there any problem in
internal contactors of the
terminal block?
Is the relay drive power
supply connected?
Change the voltage and polarity
to satisfy the specifications