is not a answer ...but I have a 2 XStream-PKG-RA (9600 baudrate.1stop bit, and no flow control) ascii protocol radiomodems ......and controller ptz at one end and a camera ptz..at the other end..with a pelco-d protocol,.....2 wires and rs 485 at each end.......but can't control the camera pan/tilt/zoom.....look like is the same problem you have.....if you find a solution ....please...help me out.