This is where the confusion arises, a 1000 line encoder does not put out 4000p/rev, the two quadrature pulse are used by many systems to read the 2 rising and 2 falling edges of the two quadrature pulses, hence the natural resolution of the encoder can be increased by x4 this way.
Some system, I have an Acroloop card for e.g. that will give you the option of X1 X2 or X4 the encoder resolution by reading one, two or four pulse edges.
The term quadrature refers to two pulses 90° apart NOT the x4 factor.
I have seen more than a few sites and posts that state 'The x4 is why it is called a quadrature encoder', Just not true.
The bottom line is a manufacturer lists the encoder as the basic pulses/rev as he has no idea how the end user will use the two pulses.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.