I'm trying to read which audio channels are currently active on my processor, a TagMclaren AV23R DP with a TMA-1 interface. I can write commands and read a response correctly e.g. using my good old DEC VT420, both to and from the RFX9600 as well as to and from the TMA-1. However, if I send the command to the TMA-1 from the RFX9600, the response is just always the same binary mess instead of the expected 2 lines of text. If I send an incorrect command, or if I set any of the interface parameters (speed, bits, parity, ...) incorrectly, I get no response at all (as expected), so at least transmission does work. I'm using 9600bps 8N1 all around, and I've tried RS232 ports 2 and 3 on the RFX and both ports on the TMA-1.

I'm just using write() and receive() on CF.extender.serial[1].

Depending on the command I send, I always get the same number of bytes back that is approximately correct for the expected response. There's an obvious correlation between what the pronto receives and what the TMA-1 sends, e.g. /-/-/-/- in the output gets "translated" to "jzjzjzjz"

I'm using the same cable when testing with the VT420, so I'd assume that those are not the culprit.

Any Ideas what could be wrong in my setup?