Counter Input >> Position >> Decoding Type

NI-DAQmx C Properties

Counter Input >> Position >> Decoding Type

Data Type: int32
Description: Specifies how to count and interpret the pulses the encoder generates on signal A and signal B. DAQmx_Val_X1, DAQmx_Val_X2, and DAQmx_Val_X4 are valid for quadrature encoders only. DAQmx_Val_TwoPulseCounting is valid for two-pulse encoders only.

X2 and X4 decoding are more sensitive to smaller changes in position than X1 encoding, with X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if vibration exists in the encoder or other noise exists in the signals.

Valid values

DAQmx_Val_X1 10090 If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
DAQmx_Val_X2 10091 Count the rising and falling edges of signal A.
DAQmx_Val_X4 10092 Count the rising and falling edges of signal A and signal B.
DAQmx_Val_TwoPulseCounting 10313 Increment the count on rising edges of signal A. Decrement the count on rising pulses of signal B.


You can get/set/reset this property using:
  DAQmxGetCIEncoderDecodingType
  DAQmxSetCIEncoderDecodingType
  DAQmxResetCIEncoderDecodingType