SCX20 Nmea problems

mikehar

New member
I'm having a problem with my SCX-20. I'm not a N2k expert so I'm sure some of what I write will be confusing.

The problem is that the SCX20 starts off ok and then it seems like it is half there. When I first connect it to the network, everything is fine. Maretron's Network Analyzer can see it, I can run the SC Setup program and it finds it too. The NN3DBB sees it too. All is good.

After some period of time, if I run the Network Analyzer, it still sees the scx20 but it no longer knows the name. The SC Setup program is no longer able to connect to it. My NN3DBB does not see it anymore either. From what I can tell, the scx20 only sends PGN 126996 when it boots up. Other devices seem to send it more often.

However, I can see that it is still sending navigation data. But since no one can see the scx20, the data isn't used.

I don't know what PGNs need to be sent out for NN3DBB to see it, perhaps that is also 126996, I don't know why all of the other devices on my net seem to be able to send 126996.

I check the network for voltage issues, errors, and device collisions. There were no problems. I did a factory reset and there was no difference.

What I do know is that because of this the scx20 is very unreliable. Does anyone know what I'm doing wrong? Any other device I've plugged in just works.

-mike
mv gallivant
 
I don't. However, this network has been in place since 2009 with no problems. I replaced a garmin gps with the scx-20. Also, during my testing, I have the scx-20 plugged into the same drop as the navnet. I have metered the network and everything looks ok from load, to voltage to shielding. I'm stumped. I would say that the scx is defective, but it's an odd way for it to fail.
 
It looks like the problem is the N2K hat on my raspberry py. The problem doesn't happen when the py is offline. Now over to that forum! : )
 
Without a descent termination of the N2K bus funny things may happen. Check if your hat as the option to switch termination on/off
 
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