Applicable Systems
CJ/CS Series
Symptoms
Registered I/O configuration does not match actual I/O; PLC cannot verify I/O table; PLC enters STOP mode.
Possible Causes
- I/O unit removed or added without updating I/O table
- I/O unit failure
- I/O connecting cable disconnected
Troubleshooting Steps
- Step 1: Check I/O table in CX-Programmer vs actual rack configuration
I/O table matches physical setup - Step 2: Verify all I/O units are securely mounted in rack
All units seated correctly - Step 3: Check I/O connecting cables
All cables connected - Step 4: If unit was replaced, verify model matches I/O table
Correct model installed - Step 5: Reregister I/O table via CX-Programmer
I/O verification passes
How to Reset
Clear via CX-Programmer: re-register I/O table, then clear FALS 80.0 error.
Frequently Asked Questions
- Q: How to register Omron I/O table?
Connect via CX-Programmer, go to PLC > I/O Table > Read from PLC or Auto-allocate. Registering tells PLC what I/O units are installed and at which slots.
Source: Omron CJ2M Operation Manual W394
Category: PLC & VFD