@dc42 Bingo, that fixed the issue! That was an oversight on my part. Thank you!

Hello,

So there are three boards in my system, 6HC, #1_1HCL (#1), and #2_1HCL (#2). Each of the cards are running V3.5.1. #1 is configured as B50 and #2 is configured as B51.

When I connect 6HC to #1, remove the jumpers on #1, and connect #1 to #2; there will be a bus connection between the 6HC and #2 only. I am not able to ping #1 "M115/121 B50" even though it is the first node in the CAN chain.

I tried doing the reverse order of 6HC > # 2 > # 1 and there is an active bus connection only for #1.

In both instances, the first node of the CAN bus line is not being recognized by the 6HC.

It is worth noting that I am powering my 6HC from a separate power supply than the 1HCL's that share the same PSU. I did run 1 cable from the negative lead of the PSU powering the 6HC to the negative lead of the PSU powering the 1HCL's.

I followed the solution to a somewhat similar problem listed in this forum(https://forum.duet3d.com/topic/30775/trouble-setting-can-addresses-for-two-1hcl-boards/8) but it did not resolve my issue. It did help me update my firmware on my 1HCL's, although.

Any help or troubleshooting tips would be greatly appreciated as I am running out of ideas for troubleshooting.

Thank you in advance!