You can set parameters for your camera/frame grabber using
x = get(src, 'Parameter');l set(src, 'Parameter', y);
src.Parameter = y
However, this just puts data into a structure. Does it change the camera settings immediately upon assignment? Do you have to get data in order to change the settings?
The take effect immediately. They are sent to the camera as soon as you execute that line. Most or all of those things that you can assign numbers to area actually methods, not properties, so they actually do stuff (talk to the camera), not just store the number in a variable.