Get Waveform Attribute
- Updated2023-02-17
- 4 minute(s) read
Get Waveform Attribute
Retrieves either the value of a single waveform attribute or the names and values of all waveform attributes.
To retrieve the names and values of all attributes, select Get All Attributes in the Behavior section of the Item tab.

Inputs/Outputs

waveform
Waveform for which you want to retrieve the attribute and value.

name
The name of the attribute whose value you want to retrieve.

default value
A value and data type that you specify. If the node does not find the attribute specified in name, it returns the default value.

error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Default value: No error

duplicate waveform
Waveform data you input in waveform.

found
A Boolean value that indicates whether the node found the attribute that is specified in name.
True | The node found the attribute specified in name. |
False | The node did not find the attribute specified in name. |

names
A 1D array containing the names of all attributes associated with the waveform.

value
The value associated with the attribute you wire to name.
If the node does not find the attribute specified in name, it returns the value passed to default value.

values
A 1D array containing the values associated with each attribute of the waveform.

error out
Error information.
The node produces this output according to standard error behavior.
Modes of Behavior
This node has two modes of behavior depending on whether you select Get All Attributes in the Behavior section of the Item tab.
Get All Attributes | Node Behavior |
---|---|
Selected | The node returns the names of all attributes and their corresponding values in 1D arrays. |
Not selected | The node searches for only the specified attribute. The names output changes to a Boolean output called found and the values output changes to a variant output called value. If the node does not find the specified attribute(s), or if it cannot convert the attribute(s) to the default value, found is False, and value displays the contents of default value. |
Waveform Attributes Set by DAQmx
Waveform signals obtained from a DAQ device include specific waveform attributes whose data you can access in your program. The following table lists the waveform attributes set by DAQmx.
Attribute | Name | Data Type | Acceptable Values | Description |
---|---|---|---|---|
Name of Channel | NI_ChannelName | String | Any value | NI_ChannelName is the name of the virtual channel producing the waveform. |
Name of Digital Line(s) | NI_LineNames | String | Any value | NI_LineNames is the name of the digital line in the waveform. |
Unit for Data | NI_UnitDescription | String | Volts, PSI, etc. | NI_UnitDescription is the units of measure for the waveform. |
Decibel Reference | NI_dBReference | Double | Finite values greater than zero | NI_dBReference is the reference value to use when converting measurement levels to decibel. |