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.
Waveform for which you want to retrieve the attribute and value.
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Default: No error
Waveform data you input in waveform.
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.
Error information.
The node produces this output according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
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 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. |
Where This Node Can Run:
Desktop OS: Windows
FPGA: Not supported
Web Server: Supported in VIs that run in a web application