Can bus wiring query

[Hot Toddy]

Hi,
My current Trident 350 setup has an Octopus 1.1 supporting a canbus connection to an SB2040 toolhead board and a Cartographer scanner probe. The Can Bus is terminated at the Octopus and Carto, with the SB2040 spliced as a spur between the two.

I now want to add a Tradrack MMU into the mix using a BTT MMB Can board. Is it OK to splice yet another spur (off the Octopus Can lines) to the BTT MMB ? Logically, this seems just like daisy-chaining the boards together, which I believe is what the Can bus spec requires. But not too sure. (Not sure why Can board vendors don’t provide ready made daisy-chaining by offering a Can-in and Can-out connections.)

The other option I have is to simply run the MMB serially over USB, in addition to 24v power lines, without the need to mess with the current Can setup. Functionally, it should make no difference if I use Can or USB. But I’d appreciate others’ experience and recommendations for which way I should go and why.

Many thanks.

 

[Maddog]

I have pretty much the same setup as you. I wanted to add a BoxTurtle MMU. ​

Yes the SB2040 was not easy to connect the Cartographer, but it works when its connected up. Termination is poorly thought out.​

I added a BIGTREETECH U2C V2.1 Adapter Board which supports CAN Bus Connection with 3 CAN Outputs. ​

The printer worked fine before adding another CAN bus, ​

I didn't want to screw around and break it. I followed the Esoterical Guide and the second CANBUS came up with little drama. ​

Now I have no problem connecting external CAN interfaces with perfect termination.​