Artemis Wiring - Fan Negatives and Finding Positive.

[wepollock]

In the Seemecnc Artemis (and consistent with the Duet documentation) the fan negatives can have a single wire connection from the Duet to an effector board.
I am assuming the Duet toggles negative on/off as needed-instructued to complete the fan circuit.
The fan needs positive to complete the circuit.

I want to confirm that the Artemis effector board is getting "positive" from the Heater E0

–the documentation from Duet indicates that Heater polarity does not matter (resistors don't care), this contrasts with the Seemecnc where "polarity matters"
--I think this difference exists for the aforementioned reason.

Does the Heater E0 work the same way in that the on/off toggle occurs on the negative side? The positive is always active?

My goal is to build a small "cable patch board" so I can switch out effectors using the existing wire harness on the Artemis.
I want the existing pinouts of the Artemis wiring to support my inventory of third party hot ends.

Am I on target here; and if so do you know if Rambo works the same way.

BTW Duet is great. Thanks for all your hard work, and seemingly limitless expertise.

[dc42]

All heaters and fans are negative-side switched on the Duet (as on other electronics). So if the heaters and fans use a common voltage (e.g. all 12V) then you can have a common positive wire feeding them all.

You can take that common positive wire from the E0 heater terminal block, but be careful: on older Duet PCB revisions, the E0 polarity is incorrectly marked on the underside of the PCB. The positive terminal of the E0 and E1 heater connectors is the one furthest away from the motor connectors.