ALSO posted in RTI forum...

Hi all, up late programming and about to pull my hair out. Does anyone have experience controlling a TOA D-901 mixer via RS-232? I'm following the protocol and not having any luck.

RTI RK2 with RP6 and CM-232.

I've checked pin-outs and that's fine, and I've tried a few variations on the commands, to no avail. Example:

For output channel one, volume step up by 3, here's what the spec says:

91H, 03H, 01H, 00H, 43H

Where 91H is the command, 03H is data length, 01H is channel attribute (output channel), 00H is the Channel Number (one), and 43H is a 3 step up in gain. By the book.

And that's all it gives ya! Anyone have any tricks they can offer?