NI-9144 encoder direction

[Tommys99]

Hello

I am using the NI-9144 with C-module NI-9421 and RT-3110 as my RT. I am trying to read the direction of my encoder. The encoder has 2 input A and B. Pulse A = 400uS and B = 400uS but A has a lead of 200uS. I am trying to determine using the FPGA the direction of the encoder. I have included a screen shot of the FPGA Vi. Also my NI-9421 has a 100uS rate so I should be able to see the leading edge between my two signals?

Thank you for your help  

[df86]

Please post the VI itself not a screen shot of it and also the actual documentation for the encoder, it's hard to see.

When you want to check for direction you need to detect with side which has a rising edge after both phases are low. Also keep in mind that with a Quadrature Encoder, your duty cycles depend on the resolution of your encoder and the speed.

The link below should provide you with more information as to what you need to do

http://www.ni.com/white-paper/7109/en/