Possible causes:
  • The wiring might be incorrect or the cable could be damaged.
  • The Modbus communication lines (D+ and D−) may be reversed.
  • If you’re using Modbus TCP, the sensor might be connected directly to a PC instead of through a network switch or hub.
  • The configured Modbus address might not match the sensor’s actual address.
  • The sensor may not be powered or the supply voltage could be too low.
Solutions:
  • Compare the wiring with the sensor’s user manual to ensure all connections are correct.
  • Use a multimeter to check for a stable 24 VDC power supply.
  • Test the cable for continuity or try a known working replacement cable.
  • Verify the Modbus address and communication settings using the S4C-FS configuration software.
  • Ensure the cable from the splitter to the sensor is shorter than 30 cm for proper detection.
  • Use the S4C-FS software’s address scan function to detect the sensor on the network.