Hitachi NJI-350B - Manual (Page 285)

Chapter 13 Troubleshooting
13-10
(d) Wrong input at input module or no input (operation problem)
The CPU runs, but the input data is not correct.
Check input signals
• Input signal voltage
• Input power supply type
• Cable disconnection
• High-speed pulse is entered
in a normal input
NO
YES
YES
NO
Check input signals
• Check input monitor
• I/O assignment
• Program
• Input signal voltage
NO
YES
LED error
∗ LED replacement may not be
performed by the user, so a
repair request must be
submitted.
Check for input error
• Check input signal source
• Check input program
• Malfunction due to noise
Input LED is not lit
Input is not read
Input LED is lit
Input is not read
Input LED is not lit
Input is read