Hello Steve,
The questions keep getting harder, but we haven't run out of answers.
It is easy to connect lots of serial devices (like the Zaon) to G3X systems since each G3X display has 3 serial ports. Since the 696 has only one serial port, the story gets a little more complicated.
The GDL39 has 2 serial ports. The first is used to communicate bi-directionally with the display device and provide the normal traffic and weather data. The second serial port is used to help us recover some of the functionality lost for the single serial port portable when the GDL39 was connected to that single serial port.
As mentioned in FAQ list on the first posting in this thread, we currently have 2nd serial port function support for NMEA Out (Fast or Slow). This gets a large group of devices previously connected to the 696 serial port going again (like autopilots), but doesn't provide a connection for devices like the Zaon or even an SL30/40.
We plan to expand on the choices available for this second serial port function, but don't have a firm date for this. At this point you would lose Zaon support if you connect the GDL39 to the single serial port on the 696, but we hope to add support back in for the Zaon (and other TIS-A compatible products like the GTX330) in the future.
Since the Aera 795/796 has 2 serial ports, you could connect a GDL39 to one port and a TIS-A device like the Xaon to the second port and have a choice of traffic systems.
One additional piece of information related to the Zaon. TIS-A devices like the GTX330 change traffic status as you fly in/out of TIS-A coverage, so we are able to allow the display to auto-switch to TIS-A when in TIS-A coverage and back to ADS-B when you fly out of the TIS-A service area. The Zaon, however, is always reporting it is in a traffic service area, so the only way we will auto-switch over to ADS-B traffic is if you turn off the Zaon. Just something to keep in mind.
Garmin Pilot is currently the only tablet/phone app that is able to use the GDL39 (via BlueTooth connection), and it does a nice job of displaying this traffic and weather information.
Let me know if I missed something, but since your 696 doesn't currently support both GDL39 and the Zaon at the same time, I skipped the details about how you would connect these.
Thanks for your interest,
Steve