Encoder | LabJack


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cgriffin33's picture

Are there any recommended rotary encoders best suited for U6? Open-collector...line driver...push-pull? Thanks.

LabJack Support
labjack support's picture
If the encoder needs power,

If the encoder needs power, one that runs off 5 volts is most convenient.

Open collector is great if it is NPN.  PNP is not bad but you need to add pull-down resistors.


Push-pull is excellent as long as it fits in the logic thresholds of the U6.  A low is <0.8 and a high is >2.0:


Line driver suggests a differential signal, which is not a natural fit, but usually you can just use the positive signal in a single-ended fashion, again as long as it fits the logic thresholds of the U6.

One other consideration is speed.  If you are using a hardware counter then speed will not be an issue.  If you are using a timer to do period measurement or quadrature decoding, however, you do need to consider the max speed of your device and the pulses/rev of your encoder: