Using myDAQ with the NI ELVISmx Function Generator Soft Front Panel



The NI ELVISmx Function Generator (FGEN) generates standard sign, triangle, and square waves. The instrument allows for the selection of the frequency, amplitude, and DC Offset of the signal, and provides duty cycle adjustment and frequency sweep capabilities.  The FGEN uses AO 0 on the screw terminal on an NI myDAQ for its output, which used AGND as its ground reference.

Waveform Settings

The waveform settings section of the function generator soft front panel provides three waveform types to choose from, and provides frequency, amplitude, DC offset, duty cycle, and modulation type adjustments.

The three waveform types can be selected by clicking on the icons for the sign wave, triangle wave, or square wave.  The frequency, amplitude, and DC offset of the signal can be changed by moving the corresponding control knob, or by directly inputting the desired value into the control below the control knob. The duty cycle adjustment is only available for the square wave output, and will be grayed out if the sign or triangle waveform types are selected.  The modulation type control allows for the selection of frequency or amplitude modulation, but is unavailable with the NI myDAQ.  To change the modulation type, an NI ELVIS system must be used.

Sweep settings

The sweep settings of the ELVISmx function generator allows for the frequency of the output signal to be changed when the sweep output is executed.

By giving values for the start frequency, stop frequency, and step you can define which frequencies will be output, and how many steps there will be when the sweep output is run.  Then by setting the step interval, the time spent outputting each frequency can be set.

To run the function generator using the sweep settings, click the Sweep button in the Instrument Control section of the front panel.

Instrument Control

The Instrument Control settings section of the Function Generator allows the user to select which device and signal route they are using to output a signal and if they’d like to run continuously, or to output a signal using the frequency sweep settings from the sweep settings section of the front panel. This section also holds stop button and a link to the help section for the Function Generator in the NI ELVISmx help.

The device drop down selection box allows a user to select any myDAQ or ELVIS unit that is connected to the system.  The device list, which includes the device numbers, is pulled from the devices and interfaces that can be seen in Measurement & Automation Explorer (MAX).  To test or rename each device, see the Configuring and Testing your myDAQ in Measurement & Automation Explorer page.

The Signal Route drop down selection box allows a user to specify which output to generate the function on.  For myDAQ units, the only option is AO 0.

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