I think I'd have to re-read that a few times to follow. I get the picture that you're going to try to mix and match, new and old equip, with different comm protocols. Sounds like it has potential to be very frustrating.
Just read your old post about having multiple plotters/gps. We have two as well. One is set up to be the master and the other the slave (their terminology, which seems non-PC these days). Only the master needs the chart chip and the slave reads off the master. This is a nice setup, as one can enter their routing on one and it reads to the other. Our master is at the nav station, where I can float plan over coffee, in the morning, before going out to face the elements. The only downside, however, is if there is a brain scramble, the master needs to be recycled off/on, which is down below. Doesn't happen often, maybe every couple of years.
Actually No... I intend to arrive a B&G only N2K system with one older Zeus T7 and a newer Zeus3 plotter. The Triton displays are compatible with both.
My present data transducers are not N2k and not readable as far as I understand so all of them will be replaced... depth, temp. speed, wind and compass. I believe there are NMEA 183 to N2K converters and B&G is going back to 183 masthead units with a converter at base of mast
I am struggling with a way to transition from the working instruments I have and the T7 which is N2k but not the latest and greatest. I do not intend a fixed mount plotter in the cockpit and will use the same coach roof "winch mount" that the T7 uses. However the T7 will go below and the Z3 will take the winch position.
I don't do route/waypoint planning ... just enter one waypoint "on the fly" as needed. So if I can simply scroll to the location for the way point and "click" I am fine. Most plotters do that. I presume I can set it from below or from the cockpit.
I am not exploring new sailing waters for the most part so the plotter is really just a device to see where I am and give me data about "getting there".
I am not interfacing AP electronically with plotter. I am the interface. and set the course on the AP informed by what I see on the plotter. Comparing boat speed thru the water and SOG is often a tell about a fouled bottom. And of course current, radar and AIS data overlays is very important to inform navigation decisions. I don't want to scroll thru pages to see what I need.... so a few separate numeric displays with large numbers works for me.
Maybe I am too used to how I use instrument data to change to a different human interface. As I wrote my old instruments work fine for how I sail and were it not for their age and coming uncertain date of demise... I wouldn't be doing this planning. And as a result I want to TRANSITION from old to new not do a one step electronics refit. But I do need to N2k back bone. So I see the first step...
transducers, and Tritons...then the 2nd plotter and radar (very useful but not used much as we are doing mostly fair weather and day sailing). I think my KVH compass can be converted (short term) from 183 to N2K and then replaced with a new N2K.
Money is an issue as well.