Modbus Fault
Schneider Electric · Altivar 312 Variable Frequency Drive
What does SLF mean?
This fault signals an interruption in communication on the Modbus bus, preventing the drive from exchanging data with a Modbus master or remote display terminal. Causes often include physical bus issues or a disconnected remote display terminal when HMI command is enabled. This results in a loss of external control, monitoring, or parameter access.
Complete Troubleshooting Guide
- 1
Check the physical Modbus communication bus for loose connections, damaged cables, or incorrect termination.
- 2
If a remote display terminal is in use, verify its connection to the drive and ensure [HMI command] (LCC) (page 61) is correctly configured.
- 3
Consult the relevant product documentation for detailed Modbus troubleshooting procedures.
- 4
Verify Modbus parameters such as baud rate, parity, and slave address are consistent across all devices.