The Predefined Connection (PdCn) object class contains connection information for intermediate devices. This object class also includes predefined dependency information. For each connection location, there are one or more objects describing the subclasses of devices that can be connected. This information is useful, for example, in verifying whether a device instance to be defined and configured can be connected to a given device.
The Predefined Connection object class contains the following descriptors:
| ODM Type | Descriptor Name | Description | Descriptor Status |
|---|---|---|---|
| ODM_CHAR | uniquetype[UNIQUESIZE] | Unique Type | Required |
| ODM_CHAR | connkey[KEYSIZE] | Connection Key | Required |
| ODM_CHAR | connwhere[LOCSIZE] | Connection Location | Required |
These fields are described as follows:
| Field | Description |
|---|---|
| Unique Type | Identifies the intermediate device's class-subclass-type name. For a device with dependency information, this descriptor identifies the unique type of the device on which there is a dependency. This descriptor contains the same information as the Unique Type descriptor in the Predefined Devices (PdDv) object class. |
| Connection Key | Identifies a subclass of devices that can connect to the intermediate device at the specified location. For a device with dependency information, this descriptor serves to identify the device indicated by the Unique Type field to the devices that depend on it. |
| Connection Location | Identifies a specific location on the intermediate device
where a child device can be connected. For a device with dependency
information, this descriptor is not always required and consequently
may be filled with a null string. The term location is used in a generic sense. For example, for a bus device the location can refer to a specific slot on the bus, with values 1, 2, 3,.... For a multiport serial adapter device, the location can refer to a specific port on the adapter with values 0, 1,.... |