H25 Rotary encoder T7 | LabJack

H25 Rotary encoder T7

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abosaad's picture
H25 Rotary encoder T7



I am trying to connect a rotary encoder.  The encoder uses 5V source, ground, and then has two outputs.  One output sends a digital 5V pulse once per revolution and the other output sends a digital 5V pulse 720 times per revolution. (One does a known degree like top dead center, and the other is used to know specific angle.)

I've connected the power and ground, and also the two inputs to FIO2 and FIO3, but I can't get any reading using LJLogM.  I'm not sure if I don't have something configured right or what.

Any help is appreciated.


LabJack Support
labjack support's picture
First go through steps 1-5 of

First go through steps 1-5 of the counter tutorial here:


Then go to the "Connecting your Signal to a Counter" section and connect your 720 PPR signal to FIO0.


That demonstrates simple counting.  If you are trying to track absolute position, we generally see encoders that have A and B signals that are 90 degrees out of phase and both provide 720 PPR, and then sometimes also a Z signal that is 1 PPR.  This is handled with quadrature decoding:



abosaad's picture
Thank you so much this was

Thank you so much this was helpful