Waveform Constant

Owning Palette: Analog Waveform VIs and Functions

Requires: Base Development System

Use the waveform constant to hold acquired data for analysis and display.

Add to the block diagram

Find on the palette

The waveform constant consists of components that include a start time, a delta t, the waveform data, and attributes. Use the Analog Waveform VIs and functions to access and manipulate individual components of a waveform.

The start time (t0) is a time stamp associated with the first measurement point in the waveform. Use the start time to synchronize plots on a multi-plot waveform graph or digital waveform graph and to determine delays between waveforms. Delta t (dt) is the time interval in seconds between any two points in the signal. The waveform data is the value that represents the waveform. An array of any numeric data type other than the fixed-point numeric data type can represent analog waveform data. Generally, the number of data values in the array corresponds directly to the number of scans from a DAQ device. Attributes include information about the signal, such as the name of the signal and the device acquiring the signal. NI-DAQ automatically sets some attributes for you. Use the Set Waveform Attribute function to set attributes, and use the Get Waveform Attribute function to read attributes.

Use the Get Waveform Components function to extract and manipulate the components of a waveform you generate. The Negate function negates waveform data and plots the results to a graph.

To represent waveform data in the front panel window, use the waveform control or the waveform graph.