Laser beta lasermike LS8000-3 - Manual (Page 39)

LaserSpeed 8000-3 Instruction Handbook
Interfacing with the LS8000-3
Part No. 93463 / Drawing No. 0921-01561 Page 39 of 221 Revision A (Sep 2007)
Because the opto-isolator in the circuit has a relatively slow response time
compared with the LaserSpeed's maximum pulse output frequency, when
using this circuit, keep the LaserSpeed's pulse output frequency below 20kHz.
Quadrature Output Phase Relationships
The phase relationship of the quadrature outputs is determined by the
direction of the measured velocity. If the velocity is a positive number, Phase
A rising edge will lead Phase B rising edge, and if the velocity is negative
Phase B will lead Phase A rising edge. For more information on the direction
input, see Operational Inputs.
Typical Full Quadrature Pulse Train with Positive Velocity