Digital Input and Output

Acquire and generate digital data with data acquisition hardware

Before you use digital channels, see Hardware Discovery and Setup.

Functions

Channel Configuration

`addinput`	Add input channel to device interface
`addoutput`	Add output channel to device interface
`addbidirectional`	Add digital bidirectional channel to device interface
`removechannel`	Remove channel from device interface

Reading and Writing Data

`read`	Read data acquired by hardware
`write`	Write output scans to hardware channels
`readwrite`	Simultaneously read and write device channel data
`start`	Start DataAcquisition background operation
`stop`	Stop background operation
`preload`	Queue scan data for device output
`flush`	Flush DataAcquisition input and output buffers

Data Format Conversion

`decimalToBinaryVector`	Convert decimal value to binary vector
`binaryVectorToDecimal`	Convert binary vector value to decimal value
`hexToBinaryVector`	Convert hexadecimal value to binary vector
`binaryVectorToHex`	Convert binary vector value to hexadecimal

Topics

Basic Workflow

Digital Channels

Transfer digital or logical values in bits via digital lines.

Acquire Non-Clocked Digital Data

Acquire a single scan of digital data from two channels of an NI device.

Generate Non-Clocked Digital Data

This example shows how to write data to two lines on an NI 6255.

Acquire Digital Data Using a Shared Clock

Share the clock of the analog subsystem on your device for the digital acquisition.

Acquire Digital Data Using an External Clock

Acquire digital data in the foreground using an external scan clock.

Acquire Digital Data Using a Counter Output Channel as External Clock

Acquire digital data using a counter output channel to generate clock pulses.

Acquire Digital Data in Hexadecimal Values

This example shows how to acquire digital data using four channels on an NI 6255.

Generate Digital Output Using Decimal Data Across Multiple Lines

This example shows how to convert decimal data and output to two lines on an NI 6255.

Generate and Acquire Data on Bidirectional Channels

This example shows how to use a bidirectional channel and read and write data using the same two lines on an NI 6255.

Generate Signals on Both Analog and Digital Channels

This example shows how to generate signals when the DataAcquisition contains both analog and digital channels.

Featured Examples

Control Stepper Motor Using Digital Outputs

Control a stepper motor using digital output ports.

Open Script

Communicate with I2C Devices and Analyze Bus Signals Using Digital IO

Communicate with instruments and devices at the protocol layer as well as the physical layer. Use the I2C feature of Instrument Control Toolbox to communicate with a TMP102 temperature sensor, and simultaneously analyze the physical layer I2C bus communications using the clocked digital IO feature of Data Acquisition Toolbox.

Open Script