generate a square wave on analog output

I am using a PXI-6229 DAQ card and I need to generate a square wave on ao0.  I am programming in C# and have found a shipping example that generates a sine wave.  I need to be able to modify the function generator that was included with the shipping example to output a 7.2kHz square wave with 50% duty cycle and 2V peak to peak.  I am attaching the function generator code.

Thanks