Wastegate operation

[Ameer Antar]

Can anyone help out and explain how the lines on the wastegate work?

I know there are 2 different wastegate part #'s for the KH vs. MC 
wastegate, but I assume they're pretty much the same. In the emissions 
diagram in the Bentley both have two vac. hose connections on them. One 
side is larger which comes from the intercooler and the other is connected 
to vacuum through a wastegate solenoid or wg freq. valve on the MC. My 
question is how does the diapragm control the exhaust and what pressures on 
each wastegate port are used by the ECU to control the boost? Thanks much.

-ameer