IBM 6094-020 Lighted Program Function Keys

I'm getting a little closer .. I have the power adapter now and the correct cabling. This device communicates over the serial port, but I have no idea how to talk to it, and I haven't even been able to get it to transmit noise on the serial port to the host PC. (I've tried a variety of bps rates.) Does anybody have IBM book SA23-2646-01 "Hardware Technical Reference: Options and Devices" ? The protocol for speaking to this thing might be in there ... If anybody else has one connected to a PC RT or an old AIX box, it would be possible to reverse engineer the protocol by tapping the serial cable and watching what comes across. It's a neat looking piece of hardware - 32 buttons, each having a controllable indicator light. But I'm getting grumpy because I have no idea how to feed it. :-( Thanks in advance, Mike