SLF1

Modbus Local Serial Communication Interruption

Schneider Electric · Altivar Machine ATV320 Variable Speed Drive

What does SLF1 mean?

An interruption in Modbus local serial communication. This means the drive has lost communication with its Modbus master or other devices on the local serial network, preventing remote control, monitoring, or data exchange. This can lead to a loss of process control.

Complete Troubleshooting Guide

  1. 1

    Check the physical Modbus RS-485 wiring, including termination resistors, for continuity and correct polarity.

  2. 2

    Verify the Modbus master device (e.g., PLC, HMI) is operational and correctly configured.

  3. 3

    Ensure Modbus communication parameters (baud rate, address, parity) match on all devices on the network.

  4. 4

    Inspect the drive's Modbus port for any physical damage or loose connections.

Source: Schneider Electric Manual