Using Differential Quadrature Encoders with the NI-9411

Updated Mar 13, 2019

Reported In

Hardware

  • NI-9411
  • Quadrature Encoder

Software

  • LabVIEW

Driver

  • NI-DAQmx

Issue Details

I have a differential quadrature encoder that I want to use with my NI-9411 C Series Digital Module, but I am unsure how to program its measurements in LabVIEW because all the examples I found seem to be meant for single-ended quadrature encoder because these examples only include three terminals (A, B and Z Index).

Solution

You can use for differential quadrature encoders the same LabVIEW examples from the NI Example Finder that can be used for single-ended encoders.

You can find the Read Encoder examples in the Hardware Input and Output >> DAQmx >> Counter Input folder when Browse according to Task is selected.
 

Additional Information

The A, B and Z index terminals of these examples use DAQmx Channels that connect to the PFI lines of the NI-9411 module. As shown in the image below, which can be found under Device Pinouts in NI-MAX, the PFI lines are routed to the differential digital inputs of this module.

Also, the NI 9411 Getting Started Guide shows a connection diagram for differential encoders.