43

Communication timeout (RS485 cyclical)

SEW Eurodrive · Drives

What does 43 mean?

A communication timeout occurred during cyclical communication via RS485. This results in the drive decelerating and stopping along its set ramp, indicating a disruption in the continuous data exchange.

Common Causes

  • Interrupted or faulty communication link between the RS485 master and the MOVIMOT® inverter.
  • Too many MOVIMOT® inverters (slaves) connected to the RS485 master for cyclical communication, causing the communication cycle to exceed the configured timeout interval (e.g., more than 8 drives for a 1-second timeout).

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check and re-establish the communication link between the RS485 master and the MOVIMOT® inverter, verifying RS+ and RS- terminal connections.

  2. 2

    Check the number of slaves connected to the RS485 master. If the MOVIMOT® inverter's timeout is set to 1 s, ensure a maximum of 8 MOVIMOT® inverters (slaves) are connected for cyclical communication to prevent timeouts.

  3. 3

    Reduce the message cycle time or increase the timeout interval if allowed by the application and master settings.

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Verified technical data. Last updated: March 2026

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