I always wondered what a charge pump was.

This is the BOB, though I don't see a reference to charge pump : http://www.slidesandballscrews.com/pdf/ZP5A-INT axis interface board manual.pdf

I can give Gary a shout & see what he thinks.

I just checked the online docs for EMC2 & it is configurable for a charge pump . Bet you it turns out the BOB isn't! :cry: