power loss recovery

sinole

if i want to use external ups for power loss detection can this config function work?

active powerloss

M581 P1 T3 S1 R0 ; PLR sensor P1 triggers Trigger3.g always (R0) TRIGGER OFF
Trigger3.g
M911 P"M913 X0 Y0 G91 M83 G1 Z10 E-5 F1000"

and also in resume wiki recommends not to home Z but would it work if i home z then rais z to 1mm below max z let say max z is 300:

resurrect-prologue.g
M116 ; wait for temperatures
G28 X Y ; home X and Y, hope that Z hasn't moved
M83 ; relative extrusion
G1 E4 F3600 ; undo the retraction that was done in the M911 power fail script
G1 Z299 F6000 ; move Z to top

would this then go to print z and keep going.

Nightowl

@sinole
I'm not sure if you want the Duet to detect the power loss from UPS specifically, but doesn't the Duet detect the power loss across the VIN from the PSU, assuming you're using one?

I was having issues with power loss over the weekend and considered a UPS for my CNC machine, but I've been 'training' with @infiniteloop in this thread, to help me nest *.g files, which might help you?

I don't know, but does the resurrect process restart the print without user intervention?

infiniteloop

@nightowl999 said in power loss recovery:

I don't know, but does the resurrect process restart the print without user intervention?

No more - see my latest post in your thread.

sinole

@nightowl999 When you use a massive ups the power doesn't drop so duet doesn't detect anything until ups is dead at that point what is the point of using ups. but ups can detect the powerloss and trigger the board on a pin.

sinole

@nightowl999 I just skimmed your thread. CNC machine is very power hungry I assume. my application is 3d printer, a small china ups is pretty massive for a BTT or MKS. i think you need a 5v ups for duet board.
the config is pretty well laid out in wiki
https://docs.duet3d.com/User_manual/Reference/Gcodes#m911-configure-auto-save-on-loss-of-power

"For Duet + SBC, a solid external 5V supply is recommended for the Duet + SBC for this feature to work. When power to the Duet + SBC is cut, the SBC may turn off before the Duet can inform the SBC about the content of resurrect.g, or the SBC may lose power while it's trying to write the content of resurrect.g to the microSD card. An external 5V buck regulator may be sufficient to keep a Duet 3 Mini 5+ and SBC on long enough. For Duet 3 MB6HC, the on-board 5V regulator might not endure long enough for resurrect.g to be written to persistent storage if the Duet powers an SBC as well. Hence we recommend using an external 5V PSU if this feature is configured. "

Nightowl

@sinole The wiki is pretty good - for a 3D printer, but doesn't really help with a CNC machine, as there are a few factors that aren't taken in to accout, specifically the spindle speed of a milling motor with a digital interface, such as the AMB (Kress) 1400 FME-P DI.

Although it appears power hungry, there still seems to be adequate time to save the data needed to restore the project, even without the 5V supply as I don't use an SBC. Mine's connected to a Windoze Surface Pro.

sinole

@nightowl999 I have a BTT UPS module do you know if I define trigger M911 can be called without voltage parameter. wiki doesn't really explain how to do planned powrloss, which is essentially what I want to setup. there is also this line that i dont understand " M911 with no parameters displays the current enable/disable state, and the threshold voltages if enabled."

Nightowl

@sinole I find the wiki somewhat lacking, especially for newbies like me!

Have you tried typing in M911 in the MDI and see what response you get?

sinole

@nightowl999 not really but it should be a misprint, i should actually try that.

sinole

@nightowl999 well looks like if you have a ups module you can manage the power recovery very well even without M911. in trigger file you can pause the printer or cnc with G25 and it makes sys/resurrect.g
after that you can just recover with m916. I will write guide if it works, I think you can use it. those ups are very cheap.