Using events can notify the application program with various states (comparison count match, error occurrence, etc.) that occurred during device operation.
Depending on the parameters passed upon the event notification, you can get what kind of event occurred and distribute the processing by the event.
Callback Function
Register previously a callback function created in advance, and
the driver calls the registered function directly upon notification.
It is necessary to handle the pointers and function pointers, the amount
of code is small and simple.t can be used for applications without Window
handle (such as console application).