Clearing PIDataPipe

All,

I'm writing a polling service that initialises a PIDataPipe:

Then every x seconds does this:

AFListResults<PIPoint, AFDataPipeEvent> events = _eventPipe.GetUpdateEvents(1000);

Lets say that my server is generating 2000 events every second, and I'm polling and getting 1000 events every second.

Does this mean that:

1 - On my first read after a second I get 1000 of the 2000 events generated in that second

2 - On my read after 2 seconds, I get the other 1000 events from the 1st second interval?

Or, does my first GetUpdateEvents clear the other 1000 events I didn't read so that when I read again after 2 seconds I'm getting new events rather than ones left over?

If it is the first case, is there a method to clear the pipe so I could do :

1 - Read 1000 events after a seond

2 - Clear the pipe

3 - Read 100 new events after 2 seonds

etc..

Couldn't see an obvious method in the SDK...

Sam R