Make an acceleration/deceleration ramp : any ideas?

[pxidr84]

Hi,

I'm currently making a 3-phase VFD for an AC motor.
The program is 70-80% done, but I've to make an acceleration/deceleration ramp.

In other words, I start with a minimum value defined by the user (for exemple : 10), and I reach the maximum value defined by the user (for exemple 1200) linearly in x seconds (again defined by the user).

Here an exemple :


So any ideas how I can do that simply?
-With a low-priority interrupt?
-With a for...next loop?
-etc.

Thanks for your future help.