Hi guys,

First of all, for clarity:
The PID-loop is already in place. It servos the motor to the position given to it and does whatever it can to bring the motor to the commanded based P,I,D and feedforward parameters. If the error between the target position and actual position gets above a setable limit the loop faults and aborts. This is one of the reasons for needing the profile generator - I can't just ask the PID-loop to move the motor 10000 QCs (quadrature counts or steps or pulses or units or whatever we want to call it) because if I do an error of an equal amount (10000) will instantly develop and the loop will fault. Even if such large errors was allowed the resulting move would be less then optimal.

The profile generators job, being discussed here, is to generate input TO the PID-loop which the motor and load is actually capable of following.
The input to the profile generator can then be "stepped" 10000 QCs. It then will generate a velocity profile with the parameters given to it. Each "tick" the profile generator will give the PID-loop a new position for it to move the motor to during the next time interval. The PID-loop is executed between 500 and 2500 times per second and so will the profile generator. At least that's the idea.

Darrel,
Although I'm having some difficulties figuring out what the worst case scenario could be with the "green line approach" I don't think doing it that way should be any problem in real life. It's better to "stretch" the deceleration phase than to violate A_Max although I would prefer it symetrical but I get what you're saying - I think.

Thanks!
/Henrik.