Generating a Repetitive Signal with an NI-DAQmx Device

You can use LabVIEW SignalExpress to generate a repetitive signal continuously. With a repetitive signal, the signal is created and loaded into the device only once, which means that there are no minimum loop rates required. You can perform this type of repetitive signal generation with a much higher sample rate than a non-repetitive noise or phase continuous signal generation. When generating a repetitive signal, you can generate using the maximum sample rate the device allows.

Complete the following steps to perform a repetitive signal generation.

1. Create the repetitive signal by importing the signal from a file using the Load from ASCII, Load from LVM, or Load from SPICE steps. You also can use the Create Analog Signal step. If you use the Create Analog Signal step, place a checkmark in the Repeated signal checkbox.
2. Pass the signal to the DAQmx Generate step, which loads data to the output buffer of the device only when the data changes. Because the file import steps and the Create Analog Signal step produce their output signal only at the first iteration, the DAQmx Generate step loads the signal into the device at the first iteration and repetitively generates the signal until you press the Stop button.

Refer to the Continuous Tone Generation and Finite Acquisition (Regeneration) example located in the SignalExpress\Examples\DAQmx directory for an example of generating a repetitive signal.