First off, the older Vx2 system doesn't share video over the network, so any place unit that you wish to view, must have a video input. The RDP139 (NN1) and RDP149 (Vx2) did not come with video inputs. They were an OPTION, so I recommend you check the units to make sure you have the RCA input connection at the back of the unit. This connection (if you have it) uses standard composite video via an RCA jack. The display will only provide a 640x480 image so the image isn't as high res, as newer systems.