Counter and Timer Input and Output
R2026bUse digital and analog counters to count clock ticks and external events. Counters enable timed acquisition and synchronization. Counters output a pulse train, count rising or falling edges, and measure other quantities including:
Frequency
Edges
PWM
Position
Pulse generation
Before you use counter channels, see Hardware Discovery and Setup.
Functions
addinput | Add input channel to device interface |
addoutput | Add output channel to device interface |
removechannel | Remove channel from device interface |
resetcounters | Reset hardware scan count for all counter inputs |
Topics
- Acquire Counter Input Data
Acquire edge counts and frequency measurements from counter input channels.
- Generate Pulse Data on a Counter Channel
Generate pulses on counter/timer device channels.
- Acquire Digital Data Using a Counter Output Channel as External Clock
Acquire digital data using a counter output channel to generate clock pulses.
Featured Examples
Count Pulses on a Digital Signal Using NI Devices
Determine the rate of rotation of an Anaheim Automation motor controller by counting the number of rising edges in the signal. The controller returns hall effect pulses (square waves) that serve as frequency feedback for motor rotation speeds.
Measure Frequency Using NI Devices
Measure frequency to determine rate of flow of fluid using a flow sensor. The sensor generates a digital signal with frequency that correlates to the rate of flow of fluid.
Measure Pulse Width Using NI Devices
Measure the width of an active high pulse using a counter input channel. A sensor measures distance from a surface and generates a pulse whose width is proportional to the measured distance. An analog channel in the same chassis provides the shared hardware clock for measurement.
Generate Pulse Width Modulated Signals Using NI Devices
Generate a pulse width modulated signal to drive a stepper motor.
Measure Angular Position with an Incremental Rotary Encoder
Acquire angular position data using an incremental rotary encoder and a multifunction data acquisition (DAQ) device with the Data Acquisition Toolbox™ quadrature encoder measurement functionality.
