RS485 2 wires on Digi one IAP

The RS485 port 1 work perfectly well using 4 wires cabling. Unfortunately, our Modbus slave uses RS485 2 wires only. What is the configuration or the cabling to use a 2 wires RS485 on port 1 instead of a 4 wires RS485?

Port 1 is the screw terminal. Keep in mind that we tie the rxd/txd +/- pins together when the device is in two wire mode.
You can use 3, or 6 for the + signal. And 4, or 7 for -. We also recommend that you use pin 5 gnd.

Thank you very much for your answer! For the cabling, no problem of course. But I did not see any command to put the IAP in 2 wires mode in the configuration wizard. Is there a special command to use with telnet or tying the pins together is enough?

RS485 is enabled using the dip switch for the serial port. I have included a link to the quickstart guide which show the different modes used by the Digi One IAP.

Thank you very much, it works now!

It’d be really cool if this were documented in a manual somewhere. Maybe include some example wiring diagrams like the rest of the industrial controls world?