I think the issue is encoder "lines" vs. "counts". The encoders on the
machines I worked on were 2,000 line encoders, which as Karl noted could
provide 8,000 counts per revolution. The US digital site uses counts, so
presumably the 720 CPR encoder is 180 line?

The terminology on this is terrible. Multiply the USdigital number by four
to get counts that your control will see.

karl