I am currently trying to design a Modbus slave device. My intention is to make it compatible with both 2-wire and 4-wire connections.

My idea was to use as 4-wire tranceiver IC, and then place a jumper in the circuit which can be set to short the RXD0 to TXD0 and the RXD1 to TXD1 if the user wants 2-wire. The jumper would have to be removed if the user wants 4-wire.

Can anyone confirm that this can work or do I need to make more alterations to the 4-wire to convert it to 2-wire?

 

Should work.

You normally link Tx+ to RX+, and TX- to RX-, sounds the same to me. Do it all the time!