Hi. After many orbits or the Sun I dug out my laser cutter fitted with an early Duet and flashed the controller with the "ultimate" DC42 firmware for the board (1.26.1)
My previous technique was to use "M571 Set output on extrude" to enable the laser from the FAN0 output but that no longer works.
Looking at the Notes for M571 in [docs.duet3d.com] it says:

"RepRapFirmware 1.20 and later do not default to using the FAN0 output, so you must send M571 with a P parameter at least once to define the pin that you wish to use."

Ok, but what logical pin number activates FAN0? All the tables of logical pin numbers I can find only list signals on the expansion header.
I confirmed this works in principle by issuing M571 S1.0 P65 and that does indeed drive pin 35 on the expansion header high during extrusion but I need an inverted signal, and I liked using FAN0 mosfet switching to ground when active for this purpose.

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RS Components Reprap Ormerod No. 481

From memory, I think the numbers for fan outputs started at 20. So 20 should be Fan0, 21 should be Fan1 etc.

Edited 1 time(s). Last edit at 03/28/2024 03:13AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].