NMEA position data from Course computer S1G

[Petersailor]

I have a MFD e7, course computer S1G and Raytheon ST60 instruments, ST60 multi and ST6002+
All system is converted to Seatalkng with use of the ng converter.

I need to have a NMEA output to get position data (DSC) for my Sailor VHF 4801 with baud rate 4800.
I use the internal gps in the MFD for positioning but I have also a separate Raystar 120 antenna installed but this is today disconnected (was earlier connected into the course computer but I disconnected it when I installed the e7)

Will the S1G NMEA output send position data or do I have to connect the VHF to the NMEA out from e7 instead?

If I connect the Raystar 120 to the S1G again will it then work? and can I then still use the internal gps in the e7?

[Chuck - Raymarine - Moderator]

Peter,

Regarding the S1G, while it is generally frowned upon to use an autopilot's NMEA 0183 output port to supply GPS data to a VHF radio, SSB, etc., it is not uncommon for owners of the S1/S1G/S2/S2G/S3/S3G autopilot course computers to do so. This practice should undertaken with later model of autopilot course computers, as they have significantly less data bridging capability.

Regarding the Raystar 120 GPS Sensor, it was produced in SeaTalk and NMEA 0183 versions, identified by the information printed on the vinyl medallion affixed to the upper shell of the GPS sensor. Which version of the Raystar 120 GPS Sensor do you own?

[Petersailor]

Hi, Sorry it is a Raystar 112LP and it has there wires, red, yellow and grey so it must be a seatalk antenna then.

[Chuck - Raymarine - Moderator]

Peter,

The Raystar 112LP had marking on its upper shell to denote whether it was the NMEA 0183 or SeaTalk version of the GPS sensor. Should the SeaTalk version of the sensor be owned, then it may be it may indeed be interfaced to the SeaTalk bus if the e7 MFD's internal GPS sensor is configured OFF ... this must be done as the legacy SeaTalk devices which you have specified do not feature support for multiple sources of GPS data. Please click here to view a FAQ addressing how SeaTalk devices may be interfaced to an a/c/e/eS/gS-Series MFD.

[Petersailor]

It is a Raystar 112LP with a Seatalk protocol.
As my system is upgraded to stng I believe I could connect this antenna to my S1G sea talk port and switch off my internal gps in the e7 and it should still give me a position FIX?

I believe I also then could use the NMEA output from the S1G to my VHF (DSC)?

[Chuck - Raymarine - Moderator]

Peter,

Per the FAQ found here specifying how SeaTalk devices may be interfaced to an a/c/e/eS/gS-Series MFD, the GPS sensor should not be connected to the SeaTalk port of the S1G autopilot course computer. The Raystar 112LP SeaTalk GPS Sensor would be interfaced to an unpowered SeaTalk bus having no more than five devices having a SeaTalk communications interface within the bus. Per the referenced FAQ, should the system feature more than five devices having a SeaTalk communications interface within the bus, then the bus will need to be divided into busses, each featuring no more than five devices having a SeaTalk communications interface. Each SeaTalk bus will be interfaced to the yellow socket of a SeaTalk to SeaTalkng Converter which will be dedicated to that bus. The SeaTalk to SeaTalkng Converters will be joined to one another using appropriate lengths of SeaTalkng Backbone Cable. The SeaTalkng backbone which includes the SeaTalk to SeaTalkng Converters will be powered via a single SeaTalkng Power Cable which will be installed at the approximate midpoint of the backbone's LEN load. The SeaTalk bus(ses) will be powered by the SeaTalkng backbone via the SeaTalk to SeaTalkng Converter(s).

If installed in the manner which I have specified and should the autopilot remain powered ON via its main power cables, then the S1G will bridge GPS data from the SeaTalk bus or SeaTalkng backbone (via the SeaTalk to SeaTalkng Converter) to 4800 BAUD NMEA 0183 for use by the VHF radio. If seeking an installation solution which would only require that the backbone be powered ON (i.e. autopilot powered OFF), then it would be recommended that a SeaTalkng/NMEA 2000 to NMEA 0183 data bridging device (ex. Actisense NGW-1-ISO-STNG, etc.) be installed as a spur to the SeaTalkng backbone and it's NMEA 0183 output leads/terminals then be interfaced to the VHF radio's NMEA 0183 input leads. If seeking to have the MFD automatically plot the positions of DSC position reports, then the NMEA 0183 leads of the VHF radio would need to be interfaced to the NMEA 0183 Port 1 or Port 2 input leads of the MFD's Power/NMEA 0183/Video Input Cable.

[Petersailor]

Thanks for the help Chuck!

[Chuck - Raymarine - Moderator]

You're welcome.