matt.miles.ang

Hi All, I need help. We are doing a project wherein we need to add 2 new PTZ's to an existing system with an old joystick and ptz. The customer doesnt want to buy a new joystick nor replace the old PTZ. The current setup is that the joystick is connected to a DIA-01 Decoder. We want it straight to the DVR. The joystick is decade old with a RJ422 Control Output from Diamond Electronics. The joystick has 3 wires Red, Black and Yellow(for ground). We wanted to integrate it with our DVR with a 2-Wire RS485. What do we do with the yellow ground? Is that possible? Do we need any adaptor to do that?