Hitachi HIDIC MICRO-EH Applications Manual page 285

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