Duet2 expansion driver is missing steps

[Johalu]

Hi everyone,

in our setup of a core xy system we are using a dispenser as extruder.
For triggering the dispenser we use the step pin of E2 on the expansion slot.
We set the extrusion factors to produce mathematically integer step results.
This setup is generally working fine. Still, irregularly single triggers (steps) are not produced by the duet.
Although we are talking about less than 0.1 percent of steps missing (measured), in our application every single step is significant.

Can anybody think of a reason for this behaviour?

Thank you.

[chrishamm]

@Johalu What firmware version are you using?

[oliof]

@Johalu do you run this dispenser in absolute or relative mode?

[Johalu]

@chrishamm We are using: FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.4.6 ELECTRONICS: Duet Ethernet 1.02 or later FIRMWARE_DATE: 2023-07-21 14:08:28

[Johalu]

@oliof We are mixing absolute and relative mode, as we produce a set of identic representations. So, for start of each representation we set the position absolute, but for producing the representation we switch to relative mode.