Solution
Unfortunately, the Test Panel does not have the flexibility to edit the waveform that you output from the module, just the sample rate of the sinewave, the maximum and minim voltage levels (range) and if you want a sine wave or a DC output.
To modify the waveform of your Analog Output module, there are two options:
1. Using the LabVIEW example located in LabVIEW >> Help >> Find Examples >> Hardware Input and Output >> DAQmx >> Analog Output >> Voltage - Continuous Output.vi:
You can configure your waveform from here, and select the desired frequency, which in this case is 800Hz.
Note: If you don't use LabVIEW to program the hardware, you can use the equivalent example for your programming environment: NI-DAQmx Example Locations for LabVIEW and Text-Based in Windows.
2. Using an Analog Output task in NI MAX as explained here: Create Tasks for NI-DAQmx Devices in NI MAX.
This won't allow the user to choose a frequency directly, but the user can select a Sample Rate and a Samples to Write values that generate the desired frequency as a result. For example, using a sample rate of 80KS/s and 100 samples to write, will produce an output of 800Hz.
