Reporting in to the group that I'm now controlling my Acom 2000A remotely with the RC-1216H. If you do this, save yourself some grief and purchase some DB-9 breakout connectors to make your cables with. This way you can also see where the wires are connected. For the cable between the amp and the RCU, that uses all 9 wires, I split it open and spliced into wires 5 and 9. A breakout connector would have made this simpler and neater For the cable between the RC-1216H and the amp, I tried using 9 wire null cables, regular cables and a null adapter. Nothing worked. I found that I had to make an "exact" cable with a DB-9F on each end. Wire pin 2 to 3, 3 to 2 and 5 to 5. My next project is to install a relay to apply 240V to the amp so I can shut it down completely.