You can buy the cable from Olevia. You have to call them and order it. It's like 30 bucks. Don't try to make your own and guess at the wiring. I did and it killed the power supply and motherboard. Luckily I was still under warranty and they sent me free replacemaents. I have a 542i. I'm not having much luck getting the 232 to do anything though. I'm trying to use it with a Crestron system. :)