[Al_The_Man]

Most Galil cards can be set up for steppers by jumper, if an encoder is used, it cannot be used in the same way as the servo PID loop, they run open loop still, and the position error is not generated.
AFAIK you have to keep interogating the encoder feedback in order to test for error and correct it by programming.
Also in stepper mode, the auxilliary encoder cannot be used.
Al.

[H.O]

(I really would rather use servos then)

Indeed....
But, a stepper with an encoder, as operated by the VSD-E, really 'is' a high pole count brushless servo-motor. And if I've understood the concept you'll get the benefit of the stepper motors high torque at low speed, yet you don't have to have the same safety margin against intermittent overload (ie. lost steps) at higher speed as when running the stepper open loop.

/Henrik.

[ger21]

Indeed....
But, a stepper with an encoder, as operated by the VSD-E, really 'is' a high pole count brushless servo-motor. And if I've understood the concept you'll get the benefit of the stepper motors high torque at low speed, yet you don't have to have the same safety margin against intermittent overload (ie. lost steps) at higher speed as when running the stepper open loop.

/Henrik.

I'm curious as to why I haven't heard of anyone using this yet?

[Xerxes]

I'm curious as to why I haven't heard of anyone using this yet?

We are keeping low profile on advertising that feature until its finished (on firmware level). Now stepper can be driven as AC servo, but it could be driven with stepper optimized algorithm to achieve greater speeds.

As servo the top speed is where motor generated voltage reaches the level of DC supply. With open loop drives speed motor can go beyond that limit (with low torque though). Similar speed range is also the goal with updated stepper firmware.

However, stepper+encoder combination is kind of pointless nowadays as you can buy a stepper sized BLDC motor (without encoder) at exactly same price. BLDC+encoder will give better performance than stepper+encoder.