Cause : Modbus communication interruption comes when communication interruption on the Modbus port if the command and/or reference value is given by Modbus.

"SLF1" fault in Schneider ATV950 drive indicate "Modbus communication interruption". This means there's an interruption in the communication between the drive and a Modbus master device (like a PLC or HMI).

Follow These Steps to Correct "SLF1 Modbus communication Fault":

1. Inspect Communication Connections:

   • Physical Inspection: Check the Modbus wiring for loose or damaged connections. Ensure that all terminals are secure.
   • Cable Condition: Look for any signs of wear or damage to the communication cables.

2. Verify Communication Parameters:

   • Configuration Check: Ensure that the Modbus parameters (baud rate, parity, stop bits) on the drive match those of the control system.
   • Address Verification: Confirm that the Modbus address set in the drive matches the expected address from the control system.

3. Run Diagnostics:

   • Diagnostic Tools: Use Schneider Electric diagnostic tools to check the status of the drive and communication settings.
   • Error Logs: Review error logs for any additional information or related communication faults.

4. Test with a Known Good Setup:

   • Substitution Test: If possible, connect the drive to a known good control system to verify communication.

5. Check for Interference:

   • Environmental Factors: Ensure that there are no sources of electrical interference (motors, transformers) affecting the Modbus communication.