I/O Module Verification Error
Mitsubishi Electric · MELSEC System Q/L Series
What does D9116 mean?
This error signifies a change in the status of an I/O module from its initial power-on state. The register D9116/SD1116 stores a bit pattern indicating the specific module number (in units of 16 points) with the verification error. This verification is conducted on I/O modules located on remote I/O stations. If the normal status is restored, the error is not automatically cleared and requires a user program to clear it.
Common Causes
- I/O module status change detected after power-on sequence.
- Discrepancy between current I/O module configuration and the expected state at power-on.
- Verification failure for I/O modules operating on remote I/O stations.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Analyze the bit pattern stored in D9116/SD1116 to identify the specific I/O module causing the verification error.
- 2
Verify the physical connections, seating, and power supply to the identified I/O module.
- 3
Confirm that the I/O module's current operational status matches its expected configuration.
- 4
Implement or execute a user program instruction to clear the D9116/SD1116 error after the module's normal status is confirmed.