how to apply a pulsating load (pressure) in simulation?

Hi

I am trying to aplly a pulsating load of about 300psi in the back side of a diaphragm which is used to pump fluid. i am struggling in defining the boundry conditions such as stroke length, and no. of strokes per minute of the piston. How and where can i find the correct reference for this?

Thanks

anthony.

SolidworksSimulation