Hi Yong, Yes, you can install automation objects in the miniport filters, nodes and pins by providing an automation table entry in the respective descriptor structures. Jeff ----- Original Message ----- From: Yong Liu To: wdmaudiodev@xxxxxxxxxxxxx Sent: Saturday, February 10, 2007 6:49 AM Subject: [wdmaudiodev] avstream audio driver and portcls audio driver? I am new to audio driver, especially to portcls audio driver. I developed an avstream virtual audio driver, and knew a little bit about avstream driver. In avstream driver, Ikscontrol interface is implemented on avstream filters and pins. clients in kernel mode can access avstream automation objects (properties, events and methods) through Ikscontrol. I just wonder if portcls has this kind of function? Thanks for your help. Yong