Well that's the easy solution...
Seriously did not think about that. Thanks!
But I'm still curious if there is a way to do it in firmware.

Hey,
I was wondering if it's possible for the DuetWifi to check the currently loaded Filament before starting a print job, as it has happened, that the wrong filament was loaded. This happens especially when having multiple gcode files for different filaments on the SD-card.
Surely the slicer would need to put the information about what filament to use into the gcode.

Is there any functionality like this in the RepRap firmware already?

Thanks,
Matthias, JMT3D