Looking for a board with RS232, RS485 port and ethernet (modbus TCP) ports


I am looking for an Arduino or compatible board that has:

  1. a serial RS232 port and a RS485 port (Modbus RTU) or
  2. a serial RS232 port and Ethernet port that can be used to program Modbus TCP.

The hardware can be Arduino or compatible boards with shield. The purpose is to build a gateway to a very old ABB PLC so that its internal data can be accessed.

Can you provide me with some recommendation of the parts so that I can make a purchase?

Thank you.



Hi William,

Why not use a Raspberry Pi Model B (has 10/100 Ethernet) and connect an FTDI RS232 USB adapter cable. Net cost would likely be less than the Arduino.

If you’d prefer to stick with Arduino, then perhaps grab one of these along with an RS232 Sheild

I am curious to hear how things go - keep us updated!

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