kallileo
Lifetime Supporting Member
RS-485 is differential signal standard with 2 wires for Data and with the third wire being used as reference ground.
Some of our suppliers suggest never use the third wire when connecting Modbus RTU devices in a RS-485 bus.
Some people say multiple ground connections cause ground loops.
I prefer using the third wire and shielded twisted pair cable with shielded on one end.
Never had problems implementing Modbus connections using just two wires probably my Modbus networks are minimal (controller to HMI connection) and share common ground.
What is your take on this?
Some of our suppliers suggest never use the third wire when connecting Modbus RTU devices in a RS-485 bus.
Some people say multiple ground connections cause ground loops.
I prefer using the third wire and shielded twisted pair cable with shielded on one end.
Never had problems implementing Modbus connections using just two wires probably my Modbus networks are minimal (controller to HMI connection) and share common ground.
What is your take on this?