F122

Send Failure (Coaxial Bus Network)

Mitsubishi Electric · MELSEC Q-series MELSECNET/H

What does F122 mean?

A send failure has occurred specifically in a bus-based coaxial cable network. This points to issues with the coaxial cable integrity, connections, or terminating resistors.

Common Causes

  • Faulty coaxial cable connection or unstable coaxial cable connection
  • Absence or incorrect connection of terminating resistors
  • General cable faults in the coaxial infrastructure

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Inspect all coaxial cable connections for tightness and proper seating

  2. 2

    Verify the stability and integrity of the coaxial cable itself, checking for damage

  3. 3

    Confirm the presence and correct connection of all terminating resistors on the coaxial bus

  4. 4

    Check for any other general faults in the coaxial cable infrastructure

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Verified technical data. Last updated: March 2026

Related Faults

Source: Mitsubishi Electric MELSEC Q-series MELSECNET/H