Arduino Nano, Uno or Mega (and possibly other). On Mega you have to configure Serial in ADVANCED SETTINGS in the sketch. W5100, W5200 or W5500 ... Tx1 <-> Tx Rx0 <-> Rx; with flow controlled by pin ...

An example of communication between arduino MEGA and variable frequency drive over Modbus. I've used this code as basis for one of the projects I've been involved. We've automated the 7.5kW blower for ...