User Defined Duty Cycle for a Square Wave Output Using the DDS Operation Mode for NI 5401, NI 5411, or NI 5431

When outputting a signal using DDS mode, a 16,384 point array, which represents the waveform, is loaded into the DDS buffer. The Configure Standard Waveform function in NI-FGEN has a 'waveform' input which automatically creates an array representing a standard waveform and loads this array into the DDS buffer. When 'square' is selected as the waveform input to this function, the square wave loaded into the buffer has a duty cycle of 50%.

If you want to output a square wave with a duty cycle other than 50%, you must create and load the raw data corresponding to this waveform into the DDS buffer manually. The following example demonstrates how to create the square wave with the desired duty cycle in LabVIEW and then demonstrates how to load this data into the DDS buffer for output.

Requirements

Filename: squareduty.vi

Software Requirements

Application Software: LabVIEW Professional Development System 7.1
Language(s): LabVIEW

Hardware Requirements

Hardware Group: Signal Source (AWG/FG/AO)
Driver: NI-FGEN 2.2

Reader Comments | Submit a comment »

were are the sub VIs?
How can I possibly use this example? I can not seem to gain any traction in LABview. I need to configure a simple routine to test a method. This example required numerous sub VIs. I have know idea were they are.
- Tim DeWeese, Copeland Corporation. trdeweese@copeland-corp.com - Nov 8, 2005