Thanks again - it works perfectly. I removed the second step however - this is handled by the gcode of the print itself:
M307 xxxxx ; PID values for quick heating
G10 P0 S180 ; set temp of tool to 180°C
M116 ; wait for temp
M307 yyyyy ; PID values for stable temps during print
; final temp is supplied by part gcode
sure, I played a lot with autotune but for some reason did not get any satisfying results with the Duet that combined a quick heat-up and a stable print temperature. I do not remember though if I changed D that much - I will try that.
Interestingly, the autotune of the old Printrboard had yielded a better result, which is why I fell back to setting the PID values with M301 for a while and simply used what the Printrboard autotune had told me on the Duet as well, but I had to resort to setting an M307 setting to define a maximum PWM since the duet does not seem to provide another way to set this - and then overwrite this setting partly with M301. (On the Printrboard I could define the max. PID drive in the firmware eeprom.)
This did not work perfectly though (unsure why - maybe due to different response times of Duet vs. Printrboard?). But for now and with Phaedrux' trick I finally have a setting I feel comfortable with.
By the way - thanks a lot for including the german translation I had sent you into the PanelDue firmware