401

No communication with Fronius Smart Meter

Fronius · Primo GEN24

What does 401 mean?

The Fronius Primo GEN24 208-240 inverter is unable to establish communication with the connected Fronius Smart Meter. This prevents accurate energy monitoring and management functions that rely on meter data.

Common Causes

  • No communication with the Fronius Smart Meter.
  • Wiring fault (e.g. incorrect or loose cable, crossed data lines).
  • Smart Meter not powered.
  • Incorrect Smart Meter address or settings.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify all communication cables (e.g., Modbus RS485) between the Fronius Primo GEN24 208-240 inverter and the Fronius Smart Meter are correctly wired and securely connected.

  2. 2

    Ensure the Smart Meter is powered on and its status indicators (LEDs) are normal.

  3. 3

    Check the Modbus address and other communication settings in the inverter's user interface to ensure they match the Smart Meter's configuration.

  4. 4

    Inspect the communication cable for physical damage or breaks.

  5. 5

    Power cycle both the inverter and the Smart Meter to re-establish communication.

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Verified technical data. Last updated: March 2026

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