They scale with the commanded (S) speed..

So if you set it to 30 seconds for 0 to 20000 RPM, then if you do S2000 M3 it will wait 3 seconds (1/10th of 30 seconds because its 1/10th of 20000 RPM requested)..

I trust I can come up to speed inside 15 seconds regardless what speed I ask for.. I can't guarantee that that my acceleration is perfectly linear, in fact I know its not..

Hi,
one possibility is to use multiple ranges. Each range is the equivalent of a gear ratio.
I know you don't have a gearbox but imagine you set up three ranges with contiguous speeds:

range 0 0-3000
range 1 3000-9000
range 2 9000-18000

Then you could also set three acceleration times. If Mach scales the acceleration time within one range it probably wouldn't matter.

If think your post processor should generate the code required to cause Mach to change gear automatically.

Craig

Tried that before posting...  Using your example, if I ask for 3000 RPM the PWM will go to 100% voltage but if I asked for 3001 rpm it will drop the PWM back down to near zero.. it doesn't scale the PWM across the ranges, it resets at each step.

Hi,
OK....well in absence of either an index signal/encoder or more useful outputs from your VFD then a fixed delay
along the lines you have proposed seems like the only solution.

I think you should be able to get the post processor to generate the required delay code rather than having to manually edit your
code.

Craig