Best posts made by Anthony

@fcwilt
It's for a Duet 2 ethernet (1.04)

Fans used for thermal regulation of the printer chamber.

The fan datasheet is requesting 25kHz. I will try a lower frequency, as the command was working in RRF2 with the default PWM frequency.

The fans have a tacho output, but never used it (even cut the wire). Is it needed in RRF3 ?

I tried with and without commenting the M563, no effect.

Ok, I managed to perform the downgrade.

I used the Duet2CombinedBinary.bin from 2.03, and the Duet2CombinedIAP.bin from the 3.1.1.

Ok, looks like a wiring issue on the PWM wire between the Duet and the fan.

Thanks for the support!