Markus

I replaced two first generation Livorsi GPS speedometers (the ones with the soldered battery) with a new old stock Livorsi=Mercury=VDO Smartcraft SC-1000 System Speedometer from around 2002 and an SC-100 speedometer of the same vintage to match my other gauges.

I expected it to be easy to connect the SC-1000 System Speedometer to the NMEA 0183 output from a Garmin GPSmap 720s, but it turned out to be nothing but: NMEA0183 is not a single standard, but has evolved over time into multiple incompatible protocols. SmartCraft used NMEA0183 version 1.5 and the Garmin used NMEA0183 version 3.01. The electric protocol changed between version 1.5 and version 2.0, and some of the GPS sentences changed between version 2.0 and version 2.3.

As a result, the Garmin cannot not provide NMEA0183 data in a format that SmartCraft can understand, no matter how much you play around with baud rates, sentences and digits. Bummer.

The answer turned out to be to use the NMEA2000 output of the Garmin instead and connect the NMEA2000 backbone to a SmartCraft junction box using this cable from Mercury:
879171T21 (T22 and T23 are longer versions).

It works like a charm.

(Quite a few people out there are struggling with this based on lots of posts on lots of online fora, but no one seems to have the answer. I hope the search engines find this post)

JanTore

Thank you

Markus

You based in Norway?

Krist

@Markus: Was the cable harness the only thing needed, I.e. does it plug into the 720s nmea 2000 in one end and the smartcraft j-box in the other end? Or are more nmea 2000 items needed?

will the garmin read the smartcraft data too or is it only one way comms?

I have the exact same setup with a Garmin 720s and Smartcraft tach+speedo. Have tried all possible nmea 0183 connections with no success.

Do you know of a retailer in Sweden who stocks the harness?

Markus

I think you can buy the cable from Marinshopen in Sweden. The Mercury parts I buy in Sweden, I buy from them.

You will need:
* An NMEA 2000 starter kit with power supply and a backbone with a few NMEA 2000 connectors
* A cable from the Garmin GPS to the backbone
* The Mercury cable, which you also plug into the backbone

I don't think you will need any terminators on the NMEA 2000 bus. At least, I didn't. I suppose that the Garmin 720 and the Mercury cable terminate the bus.

The Mercury cable only posts GPS data onto the SmartCraft bus. No data goes to NMEA 2000. If you are looking for that, Yacht Devices has a cheaper solution than Mercury, by the way.

Krist

Thanks. So basically one powercable with T, one nmea 2000 dropper cable from the 720s and a smartcraft harness per your posted serial number.

Just trying to avoid unneccesary costs for the setup, have no other nmea 2000 units.

Out of curiosity, will the smartcraft speedo only show speed or will the COG, distance and fuel to waypoint etc. also work?

Markus

Not sure - I would expect the Mercury cable to post all the GPS data that SmartCraft needs.

It is sold together with a Mercury SmartCraft GPS receiver, but can be bought separately and used with any NMEA 2000 GPS receiver.

Brennerb

So you do not need a gateway module?

Markus

The gateway module is needed if you want to go the other way:

Get SmartCraft information onto an NMEA2000 GPS.

Markus

An update on gateways:

I installed the Yacht Devices gateway to get SmartCraft information on the Garmin GPS screens. It seems to work. I will report back once I have had a chance to test drive.