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CAN-USB Stick and node server
#1
Working with someone to get the stick working with node server and signalk-to-nmea2000.

Does it support sending N2K in the "fast format"?  (more than 8 bytes per packet)

Does it overwrite the src field with it's own device id?

Is there anyway to make so that it does't echo back messages that are written to it?

thanks!
-=Scott (SignalK Team)
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#2
It should work as if you have a actisense ngt-1.
It does support fastpacket.
It does overwrite the src with it's own negotiated src (start at 27).
The TX PGNs must be enabled (actisense ngt-1 and CAN-USB security settings) This can be done in openplotter with the buttom 'TX PGN enable list'.
(Please use latest version from Github sailoog/openplotter beta!!!)
The alternative is to do it the same way as you configure actisense ngt-1.(There are some issues with the saving of the PGNs on the CAN-USB)

Is there anyway to make so that it does't echo back messages that are written to it?
No. Otherwise it would be incompatible to actisense ngt-1.
It does work fine with signalk-to-nmea2000.
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#3
Ok, I think I’ll stay away from trying to program the tx list like I do for canbus. 

I see a mix of fastpacket and “plain” on the input logs I’ve  seen.  Is this intentional? the ngt-1 always uses fast and canboat fails miserably in this case. (I’ve fixed canboatjs to handle it)

The ngt-1 does not echo back sent messages. actisense-serial used to echo back, but that been fixed. I need to have a way to tell witch messages are from “me”. 


Just to add some detail, the issue with echoing back the sent messages is that signalk-to-nmea2000 gets in a “loop”. For example, if you have gps location being converted to N2K, I send those pgns out and then n2k-SignalK sees them and sends them to sk-to-nmea2000, which converts the SignalK data to N2K again. And it goes back to the input. Add infinity.

I made the change to actisense-serial because of this and have special logic in my canbus code to make sure my sent messages doesn’t come back in.
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#4
Ok. As openplotter is able to send into N2K with canboat. I can tell you that I don' t see any actisense or CAN-USB echo when sending.
First open input diagnostic (shows all sentences coming from actisense or CAN-USB)
Select Output CAN-USB
To monitor on the PC I used Actisense NMEAReader. I see PGNs send from actisense or CAN-USB.
They don't show up in openplotter input diagnostic (no echo)
And yes there is something wrong with actisense 8 byte packets. CAN-USB sends as expected. Do you know if there is a different comand to send Actisense not fastpackets?
There should be a way.
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#5
Just to add some background to this thread.

OpenPlotter v1.2.0 now have 2 methods to input/output NMEA 2000. OpenPlotter method (canboat) and Signal K method (canboatjs). We can choose any of them when using the actisense device or the CAN-USB device. There is a tool to set your device (TX PGN, baud)

We have also added a 3 method to use a really cheap device (be careful this one is not isolated):
https://www.ebay.com/itm/MCP2515-CAN-Bus...SwKJhbQwbY

We are trying to document all this.
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#6
OK, I think I may have been wrong about the echoing back. I don't actually have a device to test with and may have been confused about the logs I was seeing.
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