Registry Settings for Serenum
This topic describes the entry values that Serenum uses for an RS-232 port in Microsoft Windows 2000 and later.
The following registry entry values are under the Plug and Play hardware device registry key for an RS-232 port:
- PortName (REG_SZ)
Specifies the name of the port. Serenum reads this value and returns the port name in response to an IOCTL_SERENUM_GET_PORT_NAME request.
- Identifier (REG_SZ)
Specifies the name of the port. Serenum reads this value. Support for the Identifier entry value is provided only for compatibility with some legacy PCMCIA devices. The use of the Identifier entry value is obsolete and should not be implemented with drivers in Windows 2000 and later. Serenum returns the port name in response to an IOCTL_SERENUM_GET_PORT_NAME request.
- SkipEnumerations (REG_DWORD)
In Windows XP and later, this entry value controls when Serenum enumerates a port in response to an IRP_MN_QUERY_DEVICE_RELATIONS request for BusRelations. This entry value is not supported by Windows 2000.
Each time the system builds a serial port device stack, Serenum sets the enumeration mode that it uses to enumerate a port. During the initialization of a port's device stack, Serenum's AddDevice routine reads the port's SkipEnumerations entry value and sets the enumeration mode as described in the following table.
Enumeration mode SkipEnumerations value Description
(or the value entry is not present)
Serenum enumerates a serial port in response to all BusRelations requests (whether initiated by a system boot or by the user through Device Manager or Add Hardware Wizard).
Skip a specified number of enumerations.
A value from 0x00000001 to 0xFFFFFFE
Serenum skips the specified number of enumerations and subsequently enumerates normally as long as the port remains enabled.
Skip all enumerations.
Serenum never enumerates a port. A device attached to the port must be manually installed.
For example, if a serial port's SkipEnumerations entry value is set to three when the system builds a port device stack, Serenum will skip the first three BusRelations requests it receives for the port. Serenum will subsequently enumerate the port in a normal manner as long as the port remains enabled.