[martinrand]

Thanks, I'll certainly take another look.
Potentially, I could generate an sigmoid function to represent position, using parameters from a trapezoidal profile.

I suppose calculating position at a given time would then be as simple as plugging t into the equation. This would then do away with the need to have 3 section for accel, max velocity and decel.

Does that sound feasible?
This was how I originally assumed things were done.