NI myDAQ is used to transmit a message in Morse Code. The user enters a string of text, the LabVIEW code changes the text into its ASCII equivalent and then compares that with a morse code lookup table. Morse Code characters can be represented in boolean format, as can the spacing between characters and words. Once the ASCII is converted into its boolean equivalent, it is then converted to 1s and 0s. When a 1 is detected, a waveform is generated, when a 0 is detected, a DC level is generated. This is then converted to an audio waveform and sent to the analog output of the myDAQ device through the DAQmx driver.
To change the code speed and pitch, on the block diagram adjust the code speed lower value to go faster, or higher to go slower. You will also have to change the code tone to change the pitch as it will go higher or lower depending on the speed.
Steven Howell Certified LabVIEW Developer Certified Professional Instructor