unable to use FrmGrab_SetMaxFps(); function to capture frames

Question

hi all
i m new in C# and I have epiphan Frame Grabber I have downloaded its SDK in which I have one C# Sample code which caputre one frame when i click button i have also installed its software that capture frame in 30 fps . I want to modifiy this C# sample to capture number of frames (30 fps) per second. there is fucntion given for capture number of frames per second and get argument value as double. FrmGrab_SetMaxFps() function

public bool SetMaxFps(double aMaxFps){
return FrmGrab_SetMaxFps(iGrabber, aMaxFps);
}/// <summary>

/// Signals the grabber to prepare for capturing frames with maximum

/// frame rate. While it currently doesn't matter for local grabbers,

/// it's really important for network grabbers (it turns streaming on,

/// otherwise GrabFrame will have to work on request/response basis,

/// which is much slower).

but when i use this function i m unable to capure desire number of frames
I need help where i should use this function and is there memory allocation for grabber to store captured image using this funtion

i have attached sample code for review

regards