addCounterInputChannel

(Not recommended) Add counter input channel

This session object function is not recommended. Use DataAcquisition object functions instead. See Compatibility Considerations.

Syntax

addCounterInputChannel(s,deviceID,channelID)

ch = addCounterInputChannel(s,deviceID,channelID,measurementType)

[ch,idx] = addCounterInputChannel(s,deviceID,channelID,measurementType)

Description

addCounterInputChannel(s,deviceID,channelID) adds a counter channel on the device represented by deviceID with the specified channelID, and channel measurement type, represented by measurementType, to the session s. Measurement types are vendor specific.

ch = addCounterInputChannel(s,deviceID,channelID,measurementType) returns the object ch.

[ch,idx] = addCounterInputChannel(s,deviceID,channelID,measurementType) returns the object ch, representing the channel that was added and the index, idx, which is an index into the array of the session object's Channels property.

Examples

Add a Counter Input Edgecount Channel

s = daq.createSession('ni')
ch = addCounterInputChannel(s,'cDAQ1Mod5','ctr0','EdgeCount');
ch.Terminal  % View device signal name for pin mapping.

Add a Counter Input Frequency Channel

Specify output arguments to represent the channel object and the index.

s = daq.createSession('ni')
[ch,idx] = addCounterInputChannel(s,'cDAQ1Mod5',1,'Frequency');
ch.Terminal  % View device signal name for pin mapping.

Add Multiple Counter Input Channels

s = daq.createSession ('ni')
ch = addCounterInputChannel(s,'cDAQ1Mod5',[0 1 2],'EdgeCount');

Input Arguments

s — Data acquisition session

session object

Data acquisition session, specified as a session object. Create the session object using daq.createSession. Use the data acquisition session for acquisition and generation operations. Create one session per vendor and use that vendor session to perform all data acquisition operations.

deviceID — Device ID

character vector or string

Device ID as defined by the device vendor, specified as a character vector or string. Obtain the device ID by calling daq.getDevices. The channel specified for this device is created for the session object.

Data Types: char | string

channelID — Channel ID

numeric value, character vector, or string

Channel ID specified as a numeric value, character vector, or string, corresponding to the specific counter channel on the device added to the session. Channel ID 0 corresponds to the device counter 'ctr0', Channel ID 1 to 'ctr1', and so on. For the related device signal names and physical pins, see the pinout for your particular device.

You can add a range of channels by specifying the channel ID with a numeric array, or an array of character vectors or strings.

The index for a channel displayed in the session indicates the channel’s position in the session. The first channel you add in a session has session index 1, and so on.

Data Types: char | string | cell

measurementType — Channel measurement type

character vector or string

Channel measurement type, specified as a character vector or string. measurementType represents a vendor-defined measurement type, and can include:

• 'EdgeCount'

• 'PulseWidth'

• 'Frequency'

• 'Position'

Data Types: char | string

Output Arguments

ch — Counter input channel object

1-by-n array

Counter input channel that you add, returned as an object containing a 1-by-n array of vendor specific channel specific information. Use this channel object to access device and channel properties. For more information on the properties, see Properties.

idx — Channel index

numeric

Channel index returned as a numeric value. Through the index you can access the array of the session object Channels property.

Tips

The properties of the channel object are:

ActiveEdge	Rising or falling edges of EdgeCount signals
ActivePulse	Active pulse measurement of PulseWidth counter channel
CountDirection	Specify direction of counter channel
Device	Channel device information
EncoderType	Encoding type of counter channel
ID	ID of channel in session
InitialCount	Specify initial count point
MeasurementType	Channel measurement type
Name	Specify descriptive name for the channel
Terminal	PFI terminal of counter subsystem
ZResetCondition	Reset condition for Z-indexing
ZResetEnable	Enable reset for Z-indexing
ZResetValue	Reset value for Z-indexing

Version History

Introduced in R2011a

R2020a: session object interface is not recommended

Not recommended starting in R2020a

Use of this function with a session object is not recommended. To access a data acquisition device, use a DataAcquisition object with its functions and properties instead.

For more information about using the recommended functionality, see Transition Your Code from Session to DataAcquisition Interface.