Hi Steve,
The limit isn't really in the resolution of the encoder per se. It's a fuction of the encoder resolution and the speed you need to get out of the motor. The VSD-E has an encoder count rate of 4MHz so if you go with a 1000 line encoder you should be able to get 60,000rpm. (4,000,000 * 60 / (1000*4))
I've personally used 3600lines encoders with the older VSD-A without problems, the motor are rated 2000rpm.
Make sure you get the encoder with differential line driver output - it'll be much more imune to noise than the single ended versions.
/Henrik. |