I am currently working on a digital input card which will feature quadrature encoder inputs. To my (basic) knowledge, quad encoders use two pulse trains that are 90 degrees out of phase with each other and sometimes an index output for reference position. This gives 3 output signals (possibly six if they are differential outputs)
Now, this is the schematic for the quadrature inputs on our card. We are supporting both single ended and differential outputs. My question is the following:
Has anyone ever used quad encoders with 4 output pulse trains? What are these I and S differential signals shown on the schematics? I cannot find any quad encoder that outputs these signals...
Thank you very much for any info.