Need help making sure my ST, STng, NMEA setup will actually work...

[svmobert]

Our boat has an existing Seatalk1 network on boat that connects the Master E80 display, S3 Course Computer, ST6001 AP Head, ST60 Wind + a Repeater, and an ST60 Tridata and a repeater. We also have a second E80 at the helm which is networked over SeatalkHS.

The Master E80 is connected to an AIS transceiver via NMEA at 38,400 of course. The AIS is the only source for GPS position data currently.

I am trying to solve two problems.. 1.) I want a redundant GPS source, and 2.) I need to feed NMEA GPS position data to my new SSB and EPIRB as well.

I purchased a new RayStar 130, plus the SeatalkNG to Seatalk converter, as well as the newer SeatalkNG to NMEA0183 kit. After reading all the manuals, both print and online, I believe I have figured out how to set this up but I have a few questions, and the information across all of the manuals doesn't really provide all the caveats involved. So if you could take a look at my diagram and let me know if this will work, that would be great! If there are changes that need to be made to make it work, that would be helpful.

My current plan is to connect the STng->ST1 converter directly off of one of the ST60 displays, and then connect a SeatalkNG backbone from that to the STng->0183 converter. Assuming this will work, I'm not clear on whether I need to supply power to the STng bus or not. Currently the S3 course computer powers the Seatalk1 bus.

Diagram
Thanks!

Richard
s/v Mobert

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Richard,

Please click here to view a FAQ addressing this subject. The key pieces of the referenced FAQ are:
- the MFD will be disconnected from the SeaTalk bus and will instead be connected as a spur to the SeaTalkng backbone ... you will need to make this change
- each SeaTalk to SeaTalk Converter will support a SeaTalk bus of up to five SeaTalk devices ... you will need to divide the current SeaTalk bus and install a third SeaTalk to SeaTalkng Converter within the backbone
- the SeaTalkbus will be disconnected from its present power source (likely the red terminal of the autopilot course computer's SeaTalk port
- the SeaTalkng power insertion point should be at the approximate mid-point of the backbone's LEN load.

Regarding the redundant source of GPS data, please note that the equipment which you have identified does not support more than one source for any specific type of data (GPS, wind, speed through water, heading, etc.). As such, any redundant GPS source of GPS data would have to be physically disconnected or switched in an out of the network. In the case of the 34800 BAUD source of GPS data, switching the MFD's NMEA 0183 port to NMEA 4800 would effectively block reception of GPS data from the AIS transceiver.

Finally, please note that many AIS transceivers do not support supplying the system with UTC (date/time) data. Beyond the obvious use for this time data, it is also used to display tide and current data for the current date/time.