Just a quick clarification before i connect up Comms cables tomorrow between the cerbo and Pylontech us 5000 , and cerbo to Multi rs solor.
Using the pylontech cable type A to cerbo Ve Can Port 1 plus termination plug
Using standard rj45 cable between Cerbo Ve can port 2 to the Multi RS… Do I need 2 Termination plugs also one at each end at the cerbo 2 port and multi Rs port. So a total of 3 terminators … ouch.
3 . Or is there a different option as only two terminations came with the Cerbo gx mk2. Dont think it can be Daisy chained . But im guessing as not clear in manual.
The multi RS is 250kbs
The bms is 500kbs
So they cant share the same can network as they use different speeds.
Ideally you want to terminate on both ends for the RS.
Yeah pylontech dont supply can terminators, but BYD do. Go figure.
Try with just the one end of the RS. (In the RS). It really is there for comms stability. So if you experience issues you will need to sort out another one.
I was talking about the terminator at the Pylontech end. Their end, where there is no need for the terminator.
The terminator at the other end is the responsibility of the other equipment manufacturer…
So OP asked, as he needed one for the GX on the bms. One is provided for that.
And two for the RS can network if you strictly follow the termination on both ends. You can just terminate the end in the Multi. But if issues are experienced another needs to be added.
A terminator is needed when the cable is longer than the 1/20 of bit time, in order to minimize reflections.
As the critical wavelength is in fact about 5 times the bus speed, a simple calculus will give you that the terminators are needed when the cable length is bigger than 12 meters for 250kbs CAN speed or 6 meters for 500kbps.
So, in theory, you don’t need a terminator at all, for normal, less than 6 meters cables.
In practice, many put them for peace of mind and because the manual says so…
I for one, don’t have any terminator for the cable between Cerbo and Pylontech (at Cerbo’s end) and no error whatsoever.
Well connected everything up, switched on and nothing went BANG which is always a result. The RS shows up on device list , Main power in and Panels all seem to be Ok but not the Pylontech… So…
Now as I have the cerbo GX mk 2 do I need to change the VE Can port to 500 Kbs within the setings somewhere ?? I put a terminator in the same Ve CAN port as the type A BMS cable but didn’t work either. Checked the cable to make sure right waay round Got 2 addidional terminators arriving Saturday.
Also do I change the Dib switch on the Pylontech 5000 as you mentioned?? i can see about 5 of them .
Yes, you need to set up the port speed and type inside the menus.
Settings → Services → VE.Can Port 1/2 → CAN-bus Profile
Take a look here: 4. Connecting Victron products
Set them all to OFF, meaning OFF = 0.
That is in the opposite direction of ON, which is explicitly drawn on the dipswitch.
Just like in the first picture where all are 0.
