F7C3
Arrival Monitoring Timeout (No Resends)
Mitsubishi Electric · MELSEC Q-series MELSECNET/H
What does F7C3 mean?
An arrival monitoring timeout occurred while waiting for a response, and the resend count was set to 0. This can happen with RECV instructions if another station is sending, or if the host is executing the instruction without a response.
Common Causes
- RECV instruction timing out when another station is executing a SEND instruction
- Host station is the instruction execution station, but a response is not received
- RECV instruction executed without the RECV instruction execution request flag turned ON
- Network communication issues or target station problems
Repair Steps & Checklist
Click steps to track your progress.
- 1
Increase the value of the arrival monitoring time in the system settings
- 2
Verify the RECV instruction execution request flag is turned ON before executing the RECV instruction
- 3
If the error persists, conduct a thorough check of the network infrastructure and the target stations
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric MELSEC Q-series MELSECNET/H