Garmin 723 not seeing any NMEA2000 sensors

[collinsp]

From post #4 "Thanks for the suggestions and no terminator on the end of the backbone. The t piece is a 2 port "

From post #10 "will try the terminators when at the boat on the weekend "

Seems sure to me.

Good point on the "2 port NMEA connector" though.


@collinsp Can you confirm what you mean here ? Are you saying that you have connected two devices to a T piece ?

Thanks for all the input Here is what I meant by a 2 port connector . . .

 

[collinsp]

Blimey! I should have read OP's comments better before replying! Of course this is the answer!

@collinsp, this PDF must be your bible: NMEA 2000 Network Fundamentals

That is super useful so thanks for this

 

[collinsp]

Out of curiosity, why the external GPS sensor?

The Garmin 723 has an internal GPS, and I would have thought that it would share this with the NMEA 2000 network (there might be a setting to enable or disable that). It's probably no problem to have two GPS sources on a network, and I don't think this is the cause of your problem - devices should be able to select which they'll use - but this seems redundant, is all.

It was already on the boat so used it and was hoping it would be a redundant source if the GPS723 went down for any reason

 

[Chiara’s slave]

And here’s a backbone with terminators in place. And a spare, input. I couldn’t be bothered to disassemble.

 

[collinsp]

I rather dismissed any comment he had on the network after the 2 port connector.

for some clarity, here’s a terminator

Thanks that is what I have not got to install on the weekend

 

[collinsp]

Thanks that is what I have not got to install on the weekend

meant got to install

 

[KompetentKrew]

A few replies have been made since I started looking for and cropping this image, so it may now be redundant, but an NMEA 2000 network must always have a backbone with a terminator at each end.

 

[Chiara’s slave]

What you have there is what I’d call a 4 port connector. It’s exactly the same as 2 t pieces (3 port connectors) screwed together.

 

[PaulRainbow]

What you have there is what I’d call a 4 port connector. It’s exactly the same as 2 t pieces (3 port connectors) screwed together.

A T piece isn't a 3 port connector, it has a single network port, the device Colin posted is a 2 port connector.

 

[Chiara’s slave]

A T piece isn't a 3 port connector, it has a single network port, the device Colin posted is a 2 port connector.

It has 4 network ports. Only two of them are for network devices.

 

[PaulRainbow]

It has 4 network ports. Only two of them are for network devices.

It has two backbone connections and a pair of network ports, it is a two port NMEA 2000 connector.

Stop digging.

 

[PaulRainbow]

NMEA 2000 Multi-port T-connector | Garmin

NMEA2000 - Multi-port T-Connector

 

[Chiara’s slave]

It has two backbone connections and a pair of network ports, it is a two port NMEA 2000 connector.

Stop digging.

More poking than digging

 

[collinsp]

Loving the banter LMAO . . . . the thingy-ma-bob as my missus calls just about everything . . . .

 

[KompetentKrew]

Thanks for all the input Here is what I meant by a 2 port connector . . .

To add to the cacophony, I would call this a double-T connector.

 

[Chiara’s slave]

On the plus side, it appears the forum may, for once, have got to the bottom of the issue.