Hoping someone can help me with some NMEA2K cable confusion.
I have a Raymarine SeaTalkNG to NMEA2K adapter cable. It has a female NMEA2K micro connector. I want to connect some Raymarine ST70 instruments to the NMEA2K backbone so I can access the data from a Garmin 750S plotter or (via an Actisense gateway and USB) on a laptop running MaxSea V12.
The only place I can see to connect the Raymarine adapter cable with the female connector is to a male (backbone) port on a Garmin T connector. Will this work? The alternative is for me to get a Raymarine adapter with a male connector that would connect to the female spur cable connector on a T.
Second question: The SeatalkNG backbone is powered. Do I need to organise a separate power feed for the NMEA2K Garmin backbone? The only things on the Garmin backbone will be a Garmin 750S plotter and 2 ActiSense gateways (one NMEA183 wired and one NMEA USB).
Any assistance or illumination much appreciated!
Roy, the STng adaptor cable you have is meant for adding a standard N2K device to an STng backbone. You can plug it right into the Garmin and that should work fine (and buy more to adapt the Actisense gateways).
Or you can get the other STng adapter cables with standard male N2K connectors, and plug the ST70's into the Garmin backbone. (SimNet works the same way, incidentally, with two types of adapter cables. And in both cases, it seems easier to find the one that adapts to STng or SimNet backbones rather than the other way, but they do exist ;-)
If you're somewhat adventurous you could join the STng and Garmin backbones so that you didn't need to mess with adapter connections. Just be sure you splice all five data, power, and drain wires well, have terminators at each end of the backbone, and a single power tap. I've even done it using the adapter cable you have from an STng tee to a standard tee and it worked OK (though it meant the STng tee was serving as a butt connector instead of a tee). But no one, including me, can promise you this will work unless they see the actual execution.
Check this entry to see how similar all the flavors of N2K wiring are:
https://www.panbo.com/archives/2008/02/n2k_cable_mixing_not_a_big_woop.html
Also consider using Maretron's free N2KBuilder app to diagram your system. It's good for clarifying connector gender, cable length, and other issues, though you have to allow for the differences between what you're using and standard Maretron gear.