[CA] Seatalk to Garmin 740s?

[skipmac]

Have a similar questions. I have an ST40 Bidata with depth/temp and speed transducers connected. Also have a Garmin 740s that is connected to a Simrad AP via NMEA2000 micro-c network (yes, my 740s is NMEA2000 capable). Where the ST40 is mounted is not completely waterproof so I want to move it to a dry spot (that I can't see from the helm) and put the depth and speed data on the NMEA2000 network.

I think this should be simple but have been unable to view or download the manuals from the Raymarine website to confirm the details so hope you can help.

This is what I think.

1. Connect the ST40 bidata to the Seatalk-Seatalkng converter (part number E22158). From photos it appears that converter comes with a cable that plugs directly into the 3-pin Seatalk port on the back of the ST40 bidata display? The transducers will stay connected to the ST40 display as before.

2. Connect the ST-STng converter to a T on my NMEA backbone which I think will take an adapter cable? Which cable and part number?

3. Is that all or will I need any additional cable, converter, adapter or black box?

The converter has 5 ports and includes two cables (power and ST) and two plugs, two terminators. Do all the ports have to be filled with cables, plugs or terminators? Assume the manual will cover this?