Quadrature Connection for Specialty Digital Configuration in Scan Mode

Updated May 9, 2023

Reported In


  • NI-9411
  • NI-9421
  • NI-9423
  • NI-9435
  • NI-9402
  • NI-9401

Issue Details

I have one of the cards listed in the white paper titled C Series Module Support for Specialty Digital Functions in Scan Mode.  I would like to configure it to be in the quadrature specialty mode. The questions I have are: 
  • How do I connect my quadrature device to the Digital I/O card once this is configured? 
  • Can I use only some pins in this mode?


As described in the Encoder Measurements: How-To Guide, most quadrature encoders have the following three signal outputs: In order to connect these signals to a C-Series digital card that supports a specialty digital functions mode, DIO0, DIO1, and DIO2 must be connected to Quadrature A, Quadrature B, and Z-Terminal respectively.


Additional Information

It should be noted that when in this specialty mode, the module outputs for position and velocity will be numbered after the quadrature readings they represent, for example, Quad0 outputs Position0 and Velocity0.

Additionally, the specialty configurations will affect the entire module.  It therefore cannot be used in the standard mode on some pins, while using specialty configuration on others.