In practice, the user should never remove the dvi cable. Here is how to configure the nStream for connection to a 2nd display for Room Linking (ISMdecoder)
1) Start the router. This powers up the packs and allows them to provide edid info to the nStreams
2) Start nStream with both video cables connected.
3) Configure he vga as primary 1024x768
4) Configure DVI as secondary 1920x1080
5) Disable the 3rd (balck magic) display