Answering my own Q

Plugged into X21, must be set to FE2 and "ext button" pressed.
Had some trouble getting it to communicate with tncserver, started to create files on the pc when hooked up, but never created any data in the file (0 size), turned out I had to check the "Shortcircuit hardware handshake" in tncserver to get it working.
Just thought I'd post this for ref

