I have a single 5500 and I have two GPS units. One is GNS480 with GPS/NAV and the other has GPS only. The GNS480 is connected to one of the serial ports and the ARINC module. The manual says not to connect two GPS sources to the same screen if you have more than one screen, but is it ok if you only have one screen? I remember something about the EFIS trying to match up the data from the 429 inputs with the 232 inputs, so does it automatically figure out which 232 input goes with the ARINC module? How should I wire this setup to work correctly? Thanks.