DmxSerial2
An Arduino library for sending and receiving DMX RDM packets.
You can find more detail on this library at http://www.mathertel.de/Arduino/DMXSerial2.aspx.
A suitable hardware is the Arduino platform plus a shield for the DMX/RDM physical protocol implementation. You can find such a shield at: http://www.mathertel.de/Arduino/DMXShield.aspx.