Jim, the Fein and the Festool as well as the older Porter-Cable were designed to by "triggered" by the shop tool they were connected to. My Fein has a two poistion switch that allows either manual or auto configuration. When I step on the go pedal, the saw comes on as well as the vac. When I step off the go pedal, the saw stops instantly but the vac continues to run to clear the hose and it shuts off about 10 seconds or so later. It was designed to run that way. So far, so good.