Transition time when changing velocites on servo motor using Flex Motion Start

[Anonymous]

I am using PCI-7344 to control a servo motor. Based on initial
evaluation, there appears to be some transition time when I tried to
change from one velocity to another instantaneously. For example,
when changing from 20 rpm/s to 30 rpm/s, I saw the velocity goes from
20 rpm/s down to 0 rpm/s before it rises back to 30 rpm/s. The total
transition time from 20 rpm/s to 0 rpm/s to 30 rpm/s takes ~500ms. Is
there any way to eliminate or at least minimize the transition time?
And maybe smoothing out the transition?

Our application may require a change in velocity as often as once per
second. (A new velocity is determined by a controller in real-time)
Thus, the transition time seems to have a signif
icant effect on our
overall experiment duration. (Note: the acceleration was left at the
default value)

Any comments or advices are welcomed.

Vanessa

[Anonymous]

Are you using the load velocity and start motion fucntions? There is a
faster way of changing from one velocity to another in velocity moves
and this is achieved by using the load velocity override function.
Basically when called, this function will scale your current velocity
up or down by a percentage and it is preemtive, meaning that no
transition time should be seen.

[Vanessa]

Thanks. It seems to be working much better now.

Vanessa