[DG] [DG] Adding STng devices to backbone

[Fastgrandad]

I have an a65 MFD with a SeaTalkng connection to an i50 tridata display via a five way connector strip which has the power supply cable occupying the third white socket. Both blue terminators are in place.

I also have an i60 wind which is connected to an ST2000+ autopilot via Seatalk 1 (yellow wire) to feed wind direction for sailing to a wind angle. These two have a separate common 12V supply feed.

In order to have the ST2000+ steer to track data from the a65 MFD, I plan to disconnect the SeaTalk 1 link and connect the i60 to the SeaTalkng network, adding an Actisense NGW1 to convert SeaTalkng track data to NMEA 0183 to feed to the ST2000+. The ST2000 will remain separately powered, and the i60 now powered from the STng network.

My question is this:

all three white sockets on the backbone are occupied, so can I connect the i60 to the second white socket on the i50 and the STng power to the second white socket on the i60, or some variation on that theme? This would avoid having to fit a second five way connector and a blue backbone cable. Or could I use the blue sockets to connect devices?

In essence I'm asking if STng devices can be daisy chained once or do they have to be individually spurred off the backbone? All devices are within a few feet of each other.

Many thanks

Paul

[Derek - Raymarine - Moderator]

HI Fastgrandad
Thank you for your enquiry.

In order to connect the i60 to the ST2000+, the i60 is working in SeaTalk mode and so cannot be connected direct to the STng backbone. You will need to use a SeaTalk to STng converter, connect the i60 to the SeaTalk connection and then connect the converter to the backbone of your STng network, by removing one of the terminators in the 5 way block, adding a blue and black backbone cable and then refitting the terminator in the empty blue socket in the converter block.

Read here and here for information regarding the use of the converter.

We do not recommend daisychaining STng displays as this contravenes NMEA protocol, they should all be individually spurred off the backbone.

[Fastgrandad]

Hi Derek,

thanks for your prompt reply and I understand your description, I think!

As I read your recommendation, there is a need to first convert the i60 SeaTalk output to STng, even though it already outputs the same information, albeit in a different sentences /format, in STng.

According to the relevant manuals, the i60 outputs NMEA2000 130306 wind data and the Actisense NWD1 will convert this message to 0183 MDA, MWD, MWV and VWR, the last of which the ST2000+ should recognise as wind direction when in wind angle mode. Similarly the MFD STng navigation waypoint data is converted to 0183 which the ST2000+ will recognise when in waypoint mode.

So I don't understand why the i60 SeaTalk output needs to be converted to STng as it seems to be an additional and unnecessary step.

Maybe I'm missing something but I don't want to add extra bits of kit that aren't necessary.

I understand about daisy chaining being prohibited under the NMEA2000 protocol.

Thanks for your patience.

Paul

[Fastgrandad]

Hi Derek,

thanks for your prompt reply and I understand your description, I think!

As I read your recommendation, there is a need to first convert the i60 SeaTalk output to STng, even though it already outputs the same information, albeit in a different sentences /format, in STng.

According to the relevant manuals, the i60 outputs NMEA2000 130306 wind data and the Actisense NWD1 will convert this message to 0183 MDA, MWD, MWV and VWR, the last of which the ST2000+ should recognise as wind direction when in wind angle mode. Similarly the MFD STng navigation waypoint data is converted to 0183 which the ST2000+ will recognise when in waypoint mode.

So I don't understand why the i60 SeaTalk output needs to be converted to STng as it seems to be an additional and unnecessary step.

Maybe I'm missing something but I don't want to add extra bits of kit that aren't necessary.

I understand about daisy chaining being prohibited under the NMEA2000 protocol.

Thanks for your patience.

Paul

[Derek - Raymarine - Moderator]

Hi Fastgrandad

From your description, you have the i60 connected to the St2000+, this must be connected through SeaTalk, because that is all the ST2000+ understands. therefore, if you then want to connect to STng, the the SeaTalk data needs to be converted to STng and this is where the converter comes in. Leave the existing SeaTalk network in place, so the i60 communicates with the ST2000+, simply connect the SeaTalk connection of the converter to the SeaTalk link between the i60 and the St2000+.

From what I understand you want to connect the NMEA0183 from the plotter AND the NMEA 0183 from the Actisense NWD1 to the NMEA0183 input to the ST2000+?

If yes, then you cannot do this - only one NMEA0183 source can be connected to an NMEA0183 input, you are suggesting connecting 2 sources to one input? This you cannot do.

The suggestion I made was a lot simpler, use the SeaTalk to STng converter and it will work both ways, it will allow compass and wind information to be shared onto STng and it will allow track information from the plotter to be shared with the ST2000+, the converter works in both directions.
Thanks
Derek

[Fastgrandad]

Thanks Derek, I think I've got it now. I hadn't realised that Seatalk lines can be commoned together.

So I just need the SeaTalk to STNG converter, a backbone cable to join it to the STNG backbone and a SeaTalk cable with bare ends to join to the SeaTalk link between the i60 and the ST2000+ at the junction box.

I think my proposed solution might have worked as I was combining the i60, MFD and i50 as STNG sources on the backbone, connecting to the Actisense and converting the STNG to 0183 which, according the the manual, the ST21000+ understands. This would have dealt with the multitalker/single listener issue.

Either way, I'll go with your solution as it's more elegant and leaves vacant STNG ports for additional devices e.g. AIS.

Thanks again

Paul

[Derek - Raymarine - Moderator]

Thanks Fastgrandad

You're welcome

Derek