Connecting NMEA 2000 and SeatalkNG

Blue Drifter

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Grateful for some advice. I have 1 x NMEA powered backbone incorporating (all Garmin) 750 Chartplotter which is itself being fed AIS info from a NASA AIS Engine 2 via NMEA 0183, wind and DST transducer feeding 4 x GMI10 MFDs. I have just added a Raymarine powered backbone (EV100 tiller pilot) which comprises a heading type sensor, a P70 display, and a black box to control receive the data and control the actuator arm.

In order to get wind and position info into the autopilot I would like to join the two backbones but cannot see any obvious off the shelf simple mechanism.

Can I just splice the NMEA 2000 backbone cable to the SeatalkNG backbone cable with an appropriate terminator at the each end, and remove one of the power sources?

So much for the concept of NMEA2000 plug and play!
 

lpdsn

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Grateful for some advice. I have 1 x NMEA powered backbone incorporating (all Garmin) 750 Chartplotter which is itself being fed AIS info from a NASA AIS Engine 2 via NMEA 0183, wind and DST transducer feeding 4 x GMI10 MFDs. I have just added a Raymarine powered backbone (EV100 tiller pilot) which comprises a heading type sensor, a P70 display, and a black box to control receive the data and control the actuator arm.

In order to get wind and position info into the autopilot I would like to join the two backbones but cannot see any obvious off the shelf simple mechanism.

Can I just splice the NMEA 2000 backbone cable to the SeatalkNG backbone cable with an appropriate terminator at the each end, and remove one of the power sources?

So much for the concept of NMEA2000 plug and play!

I've now got three Seatalk ng to Device NET spurs, but I've not found anything for joining the two backbones and I doubt anything will exist. Seatalk ng is supposed to be standard DeviceNet the same as other NMEA2000, but with different proprietary connectors so they can bump up the price. Once they've got you on their backbone I doubt they'll provide the means to release you

There's a good chance you can splice the cables together to form a single backbone, but you're on your own if it doesn't work. As you say, you'll need the 60 Ohm resistor at each end of the extended backbone still, but not it the middle, and a single power source. I don't know if the wire colours differ from standard as I've never cut into a Seatalk ng cable

If it were me I'd buy a short length of the ng backbone, so it's at least sacrificial if it goes wrong. You'd need to get an appropriate DeviceNet connector to replace the proprietary connector.

Also bear in mind that it runs at something over 200Kb, so you'd need to be neat and tidy with your connections and shielding.

Worth reading up on DeviceNet & CAN bus so you have a good idea what you're looking at when you start cutting and also what should go where in the standard arrangement.
 

Talulah

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You can do as you suggest. In affect merging the two backbone cables into one with a terminator at each end. The drop cables can then be added anywhere along the merged backbone. Drop down to one power cable.
 

Blue Drifter

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Thanks very much for the rapid responses. I like the idea of using a short length of SeatalkNG backbone to reduce risk/cost. I have also looked at - http://www.panbo.com/archives/2008/02/n2k_cable_mixing_not_a_big_woop.html - who also suggests it is possible but with the usual health warnings.

If I make up the connections and properly insulate individual wires, can kitchen foil be used as shielding within the join?
 

knuterikt

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Thanks very much for the rapid responses. I like the idea of using a short length of SeatalkNG backbone to reduce risk/cost. I have also looked at - http://www.panbo.com/archives/2008/02/n2k_cable_mixing_not_a_big_woop.html - who also suggests it is possible but with the usual health warnings.

If I make up the connections and properly insulate individual wires, can kitchen foil be used as shielding within the join?
Get a field intstallabel plug to replace on of the seatalkNg plugs on a seatalkNg backbone cable.
 

lpdsn

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If I make up the connections and properly insulate individual wires, can kitchen foil be used as shielding within the join?

I'd probably try doing as Knuterikt suggests, which is to fit a DeviceNet backbone plug onto the end of the cut Seatalk ng cable. So you can use the existing Seatalk shielding. Chandlers and marine suppliers might not be able to get you one, but remember DeviceNet is used in industrial applications too.

So then you'd have something like:

NMEA2000 Backbone <-> NMEA2000 T-Piece <-> Homemade Backbone Cable <-> Seatalk ng T-piece <-> Seatalk ng backbone
 

ianj99

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Thanks very much for the rapid responses. I like the idea of using a short length of SeatalkNG backbone to reduce risk/cost. I have also looked at - http://www.panbo.com/archives/2008/02/n2k_cable_mixing_not_a_big_woop.html - who also suggests it is possible but with the usual health warnings.

If I make up the connections and properly insulate individual wires, can kitchen foil be used as shielding within the join?

Actisense supply a devicenet to stng cable if you want to connect their nmea to n2k interface to a Stng bus. Its about a metre long but they won't sell it separately.

http://www.actisense.com/news/26-ne...ble-seatalkng-to-nmea-2000-adaptor-cable.html

So looks like you will have to splice cables.
 

knuterikt

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I'd probably try doing as Knuterikt suggests, which is to fit a DeviceNet backbone plug onto the end of the cut Seatalk ng cable. So you can use the existing Seatalk shielding. Chandlers and marine suppliers might not be able to get you one, but remember DeviceNet is used in industrial applications too.

So then you'd have something like:

NMEA2000 Backbone <-> NMEA2000 T-Piece <-> Homemade Backbone Cable <-> Seatalk ng T-piece <-> Seatalk ng backbone

Here is a link to one form Garmin https://buy.garmin.com/en-US/US/sho...0-field-installable-connectors/prod11644.html
 

knuterikt

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Actisense supply a devicenet to stng cable if you want to connect their nmea to n2k interface to a Stng bus. Its about a metre long but they won't sell it separately.

http://www.actisense.com/news/26-ne...ble-seatalkng-to-nmea-2000-adaptor-cable.html

So looks like you will have to splice cables.
You can buy the same cable from Raymarine, but it's supposed to be used to adapt devicenet to the stNG backbone - not extending the backbone.
You can find the Raymarine adapter cables here http://www.raymarine.com/view/?id=5536&collectionid=9&col=1617
 
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Pye_End

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Raymarine include a small connector box with one of their STNG kits (perhaps wind?). The box itself is not shielded. I have used it to cut and re-join the STNG backbone with no ill effects - can't see why it can't be used to join to a 2000 backbone instead.

I have a feeling one of the Raymarine manuals talks about running both backbones, but I can't find it at the moment. If it turns up will post the link.
 

Blue Drifter

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Once again thanks for the responses, very useful and especially knutterikt for the links etc.

I will go down the field installable connector onto a short SeatalkNG backbone route and will post the outcome here in a couple of weeks.

Not a good experience and I suspect Raymarine are particularly guilty of ignoring the plug and play concept.
 
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knuterikt

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Not a good experience and I suspect Raymarine are particularly guilty of ignoring the plug and play concept.

One of the reasons for Raymarine special plugs & cables is backwards compatibility with older Raymarine Seatalk stuff.
You can find more here http://www.raymarine.com/view/?id=400
But the downside is more complex integration and it can be viewed as a vendor lock in, But Raymarine is not the only one...

I checked for possible use of AIS data to do a DSC call without typing in MMSI numbers this spring.
Most VHF manufacturers can only do this from a compatible MFD..
Seems only Standard Horizon could do this.
 

pvb

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Not a good experience and I suspect Raymarine are particularly guilty of ignoring the plug and play concept.

On the contrary, it could be argued that Raymarine encouraged the plug'n'play concept with their Seatalk system. OK, they used proprietary plugs/sockets, which is a pain, but they did away with a lot of fiddly NMEA wiring tasks. And, as we read here all the time, connecting fiddly NMEA wires seems to be beyond many yachtsmen.
 
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