Optical encoders are defined in different ways that make things a bit confusing.

A 1000 LINE encoder puts out 4000 pulses per revolution (aka PPR).

A 1000 PPR encoder has 250 lines.

When people order encoders they are usually defining the number of lines on the encoder disk. The pulses per revolution (or count) is allways 4x the number of lines.

The economy CUI encoders are not optical at all and are switch configurable as to the count output.

As a line is read it goes through 4 stages (pulses) then repeats. This is how it can determine direction.
  • A on, B off
  • A on, B on
  • A off, B on
  • A off, B off


Hope I have not confused you more. ( I did not get into the I or Z (index) channel. )