Hello.

We have a plc in a mobile panel. We need to connect a modbus cable to the panel at a number of stations. Is there a specific modbus plug and socket that needs to be used or would a standard one be OK?

Thank you

 

The Modbus serial standard includes some recommendations on RJ45 for RS-485 which could be used, but there is no common standard in the market.

You might want to include some buffered (or fused) power output.

For robust, waterproof solutions, I myself would look at the DeviceNET cable/plug/socket products out there, which are 5-pin (2 for power, 2 for bus, 1 ground). If I remember right, CANBUS is 100-ohm cable, but that should be close enough to the expected 120-ohm of RS-485 to not have impact at sub-100 meter distances.