Solved CAN Connections Not Working

[xtarr]

I am running a Duet 3 6HC Mainboard with 3 Expansion boards. When I started it up today, all of the expansion boards did not have communication.

I had communication in the past though with the same cables. I also tried moving the connections to see if I could get communication to even one board but had no luck. I tried resetting the board as well but I would get 4 flashes or no communication to the main board for a firmware update.

Only thing I could think is that I upgraded to firmware 3.4 recently but even after the upgrade I had communication between the boards.

[dc42]

@xtarr what do the STATUS or DIAG LEDs do after power up, on the main board and on each of the expansion boards?

[xtarr]

@dc42 The mainboard blinks once a second. One of the expansion board's diag lights is not blinking at all. The other 2 boards' lights are blinking rapidly.

[dc42]

@xtarr I suggest you take one of the expansion boards whose LED blinks rapidly and connect just that board to the main board via CAN. Try different CAN cables in case you have a break in the one that connects to the main board.

The board that doesn't blink at all may be faulty, or it may have a long startup time (which can be fixed by updating its bootloader if it does start up eventually).

[xtarr]

@dc42 OK, I tested all 3 cables that were working on a board blinking rapidly but I did not have any luck.

[dc42]

@xtarr if all 3 boards and cables were definitely working before, then it sounds as though the socket or CAN transceiver or common mode choke on the main board has failed. Does the inside of the socket look OK? The CAN transceiver chips are the 8-legged ones close to the socket.

Please confirm that you are providing VIN power to the main board and using the internal 5V regulator (so that we can be sure that the CAN transceiver is getting a good 5V supply); also that the loss of communication wasn't triggered by a firmware upgrade.

[xtarr]

@dc42 Sorry I was being stupid and had the CAN cable in the ethernet port of the mainboard. This is solved

[dc42]

@xtarr I guess that's an easy mistake to make! We'll look out for it next time this type of issue comes up.

Regarding the board that doesn't blink, if you leave it connected for long enough then it may start working. Then update the bootloader, see https://docs.duet3d.com/en/User_manual/RepRapFirmware/Updating_bootloader.

[xtarr]

@dc42 Yeah I had to set that board to a new ID but now everything is working. Thanks!