HSC Math question

[Tharon]

Hello, I'm setting up a HSC on a Micrologix 1400 with a Quadrature encoder. Everything is working correctly but I'm questioning my math I'm using to scale the counts to real world units. My encoder says I have 1um between the A and B pulses. So I used that as my distance per count setup, but I think it's off by quite a bit. I have my HSC setup for a standard Quadrature I seem to be off by a factor of 4, if I set it up for Quadrature x4, I get values that seem a lot closer to the real world units.

If I want 1um per count, I have to use the 4x mode? If I want to use the standard Quadrature mode, I need 4um per count? Can anyone help shed some light on the x and 4x and the distance between the A and B signals?

If you need more device specifications, just ask. Thanks.

 

[bernie_carlton]

Here is a presentation which might help you understand.

 

[Tharon]

Thanks, that does help. I wasn't sure if the pulses being 1um apart meant that the pulse was on for 2um, and off for 2um. Seems like that is the case.

Edit:
I guess that does make sense. I was looking at it from the rising edges being 1um apart, but I probably should have interpreted it as every edge being 1um apart.