addoutput

Add output channel to device interface

Since R2020a

Syntax

addoutput(d,deviceID,channelID,measurementType)

ch = addoutput(___)

[ch,idx] = addoutput(___)

Description

addoutput(d,deviceID,channelID,measurementType) adds the output channel channelID of device deviceID to the specified DataAcquisition interface, d, configured for the specified measurement type.

The channel information is available from the DataAcquisition Channels property.

ch = addoutput(___) adds the channel and returns a channel object.

[ch,idx] = addoutput(___) adds the channel and also returns the channel index from the DataAcquisition interface. The channel index reflects only the sequence in which channels are added to the DataAcquisition; not to be confused with the device channel ID.

Examples

Add Output Channels to DataAcquisition

Add multiple channels to a DataAcquisition, and use indices to view their settings.

d = daq('directsound');
ch1 = addoutput(d,"Audio3","1","Audio");
[ch2,idx2] = addoutput(d,"Audio6","1","Audio");
d.Channels

    Index     Type      Device     Channel    Measurement Type        Range            Name   
    _____    ______    ________    _______    ________________    ______________    __________

      1      "audo"    "Audio3"      "1"          "Audio"         "-1.0 to +1.0"    "Audio3_1"
      2      "audo"    "Audio6"      "1"          "Audio"         "-1.0 to +1.0"    "Audio6_1"

Access one of the channel settings using its index.

d.Channels(idx2).Type

    'AudioOutputChannel'

Input Arguments

d — DataAcquisition interface

DataAcquisition object

DataAcquisition interface, specified as a DataAcquisition object, created using the daq function.

Example: d = daq()

deviceID — Device ID

character vector or string

Device ID specified as a character vector or string, as defined by the device vendor. Obtain the device ID by calling daqlist.

Example: "Dev1"

Data Types: char | string

channelID — Channel ID

numeric value, character vector, or string

Channel ID specified as a numeric value, character vector, or string; often indicating the physical location of the channel on the device. Supported values are specific to the vendor and device. You can add multiple channels by specifying the channel ID as a numeric vector, or a cell array of character vectors. The index returned for this channel in the DataAcquisition display indicates the position of this channel. This channel ID is not the same as channel index in the DataAcquisition: if you add a channel with ID 2 as the first channel in a DataAcquisition, the DataAcquisition channel index is 1.

Tip: For best performance when adding multiple channels, specify the channels as a vector in one call to addoutput, rather than calling addoutput for each channel.

Example: "ao2"

Data Types: char | string | numeric | cell

measurementType — Channel measurement type

string | character vector

Channel measurement type, specified as a string or character vector. measurementType represents a vendor-defined measurement type. Valid measurement types include the following:

Measurement Type	Subsystem
'Voltage'	Analog Output
'Current'	Analog Output
'Digital'	Digital I/O
'PulseGeneration'	Counter Output
'Audio'	Audio Output
'Sine'	Function Generator
'Square'	Function Generator
'Triangle'	Function Generator
'RampUp'	Function Generator
'RampDown'	Function Generator
'DC'	Function Generator
'Arbitrary'	Function Generator

Not all devices support all types of measurement.

Example: "Voltage"

Data Types: char | string

Output Arguments

ch — Channel

channel object

Channel, returned as a channel object with properties depending on the measurement type as described in Channel Properties.

idx — Channel index

numeric

Channel index, returned as a numeric value. With this index, you can access the array of the DataAcquisition Channels property.

Version History

Introduced in R2020a