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victronvalhowell6283 avatar image
victronvalhowell6283 asked

Cerbo can bus connections and termination

I have a system with Victron lithium batteries and a Lynx BMS, Cerbo, NMEA2000 cable and a Wakespeed 500 ext alternator regulator. All talk on the VE can bus. There is also a Quattro inverter/Charger on ve direct bus.

I am using the Victron cross over cable to connect the WS500.

My issue is that the can bus needs one terminator at each end. See the attached drawing. With the NMEA cable there is only one connection and effectively closes one of the two necessary termination ports. How can I put two terminators in the system?

paperchris-sd-vessel-mods6.jpeg

VE.Can
paperchris-sd-vessel-mods6.jpeg (220.0 KiB)
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2 Answers
Sarah avatar image
Sarah answered ·

Hi @victronvalhowell6283 In theory you just need to have the far end of the NMEA2000 network terminated and the VE.Can network terminated at the other end - you will be creating one stretched network over two different physical topologies. In practise how you do this may wary depending on the type of NMEA2000 network you have. Victron have a diagram somewhere that depicts this but I can’t find it at the moment.

Specifically for a Raymarine SeaTalkNG network you need a backbone cable between the STNg network and the VE.Can to NMEA2000 cable to bridge the two networks. You cannot use a spur cable to do this - doing so would result in three terminators and a lot of complaining instruments.

I hope this helps - Sarah


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Sarah avatar image Sarah commented ·
Also please check the documentation for the layout of the VE.Can network. From memory you need the wakespeed to be the last device and use its own terminator.
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victronvalhowell6283 avatar image victronvalhowell6283 Sarah commented ·
Thanks. I will check this out.
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Dan Cordell avatar image Dan Cordell victronvalhowell6283 commented ·
Were you ever able to get this working? I've got the same setup, with a WS500 and Cerbo (and a Lynx BMS) and while it appears to work with the NMEA2k network on a basic level, my Raymarine i70s and p70s displays won't play nice: if I hook up 3, they all die.


I've noticed I'm not getting a consistent resistance across the CANH and CANL pins when the VE.Can->nk2 converter is plugged into the system, it's jumping around.

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Kevin Windrem avatar image
Kevin Windrem answered ·

Isn't there a separate VE.Can bus for the BMS? I think it runs at a different baud rate than the other devices.

Quattro would connect via VE.Bus not VE.Direct.

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victronvalhowell6283 avatar image victronvalhowell6283 commented ·
You are correct re the multi on the VE bus. I misspoke. However there is only one VE can bus so everything has to go on that.
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Kevin Windrem avatar image Kevin Windrem commented ·
Just looked. Cerbo does have two CANbus connections: VE.Can and BMS-Can.

However, the Lynx BMS is shown to connect to VE.Can in it's manual.

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bathnm avatar image bathnm Kevin Windrem commented ·
Correct. The BMS.Can port runs at 500Kb/sec and is for batteries that support that standard.
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