The quadrature interface was originally developed for incremental measuring systems.
Here the material measure is applied to a glass pane or strip. This is then scanned with optical systems. Two signals are generated, i.e. an A and a B pulse with a positive or negative phase offset of 90° respectively, depending on the direction of movement. The number of A or B pulses is a measure of the distance covered, and the pulse width of the A/B pulses is therefore dependent on the speed of movement.
In addition, optical systems usually have a reference track, which only outputs a signal once along the entire measuring distance in order to reference the incrementally determined position. This is necessary to derive an absolute position from the A/B pulses which follow.
No reference traverse is necessary for absolute measuring position and rotary sensors as, for example, is the case with magnetostrictive position measuring systems. A magnetostrictive position measuring system with a quadrature interface transfers the correct number of A/B pulses in accordance with the current absolute position on request.