Two NMEA2000 backbones

[sdonx]

Can I run a small second NMEA2000 backbone in my tower connected to a TZT12. I am thinking a SCX20 and an AIS, and have it communicate thru the TZT3 network to all devices (TZT2BB & TZT16F)?

 

[Quitsa]

Unless something has changed, all of the TZT devices have to be on the same NMEA 2000 backbone. So you can have three MFDs on drops off the same backbone but you can't do what you propose and have some MFDs on one backbone and another on the same network on a second backbone.

On my boat we had ti run a long cable to extend the backbone to the tower helm and then run drops off that cable to the SCX-20 and other NMEA 2000 sensors mounted up there.

 

[Johnny Electron]

TZT devices have to be on the same NMEA 2000 backbone.

Quitsa is totally correct. With an exception for the older NN3D; you can only have one NMEA 2000 network for which the MFDs connect. If one MFD connects to 2000 bus, they all must connect. With TZT and above; it is all or none when it comes to the 2000 connection.

 

[sdonx]

I never would of guessed that. OK, now the tower MFD will still have all the info from the Helm backbone available to it, correct.

 

[Quitsa]

I never would of guessed that. OK, now the tower MFD will still have all the info from the Helm backbone available to it, correct.

Yes, that should be the case via the ethernet connection. The benefit of dong what we did and extending the backbone is that you get redundancy if something happens to the MFDs on your network that are connected to NMEA 2000. In my case, if any one of the three MFDs is operating, all of the NMEA2000 sensor information will be available on it regardless of whether the others are working.