Syntax

    struct AttributeInfoStruct 
    { 
       LONG    attributeID;
       LONG    attributeType;
       LONG    attributeLength;
       BYTE    attributeName[64];
    };
    

Fields

attributeID

(IN) A 4-byte field containing a unique ID for the attribute being registered. Currently, NWPA defines the following attribute IDs:

Value	Description
0x44454D0A	Media Type
0x5241430E	Cartridge Type
0x494E5509	Unit Size
0x4F4C420A	Block Size
0x50414308	Capacity
0x4552500E	Preferred Unit Size
0x4D455209	Removable Device
0x41455209	Read Only Device
0x50415412	Tape Position Size
0x5041540F	Tape Media Size
0x50415411	Tape Write Format
0x50415410	Tape Read Format
0x4E494D12	Minimum Block Size
0x58414D12	Maximum Block Size
0x54414415	Data Compression Information

attributeType

(IN) A 4-byte field indicating the data type of the infoBuffer parameter for the get/set entry points associated with the attribute being registered through CDI_Register_Object_Attribute. The data types are defined as follows:

Value	Description
0x00000001	String
0x00000002	BYTE
0x00000003	WORD
0x00000004	LONG
0x00000005	Other Indicates that the calling application knows what data type to expect from the target CDM.

attributeLength

(IN) A 4-byte field containing a value that indicates the byte-length of the infoBuffer input parameter to the get/set entry points associated with the attribute. These entry points are registered during CDI_Register_Object_Attribute along with the attribute.

attributeName

(IN) A 64-byte field containing a byte-length-preceded string. The string contains the ASCII codes that make up the name of the attribute being registered, and it is also NULL terminated.

Remarks

A CDM can register multiple attributes, one attribute for each call to CDI_Register_Object_Attribute. The CDM is expected to maintain an instance of this structure for each attribute it registers.

By registering device attributes with the Media Manager, the CDM can present specific information about a device's operational modes to the application layer. For example, a tape CDM can inform an application that its tape device supports multiple block sizes.

For more information about attributes, refer to the technical reference information on the CDI_Register_Object_Attribute API.

A copy of this information is passed to the Media Manager when the CDM registers an attribute by calling CDI_Register_Object_Attribute.