deviceId
String that contains the device ID. You can obtain this string by enumerating the available WIA devices on your machine.
Use this function when working with multiple WIA devices installed on a machine in order to select the WIA device without displaying the Select Device dialog. To do this, enumerate the WIA devices by calling the EnumDevices method. Then use it to keep a list of all received device IDs. Then call SelectDevice method using the device ID for the device to be selected.
Refer to WiaSession.EnumDevices