F7C4

No Communication After Resends

Mitsubishi Electric · MELSEC Q-series MELSECNET/H

What does F7C4 mean?

Communication failed persistently even after executing the designated number of resends. This indicates a fundamental communication breakdown that retries cannot overcome.

Common Causes

  • Persistent network communication failure
  • Issues with the target station
  • Insufficient arrival monitoring time

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Increase the value of the arrival monitoring time in the system settings

  2. 2

    Conduct a thorough check of the entire network infrastructure for physical faults or misconfigurations

  3. 3

    Verify the operational status and configuration of the target stations

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Verified technical data. Last updated: March 2026

Related Faults

Source: Mitsubishi Electric MELSEC Q-series MELSECNET/H
Mitsubishi Electric Error F7C4: No Communication After Resends — Troubleshooting Guide | ErrorLib