Spectra Logic Spectra 2k, Руководство по разработке

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Chapter 10. Read Element Status—B8h
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In the data in phase, the library sends element status data in the format defined by the
SCSI-2 standard. This data consists of the following:
• Element Status Data Header (8 bytes), as shown in Table 10-3.
• Element Status Pages, one page for each element type reported, each with the
following format:
• Element Status Page Header (8 bytes), as shown in Table 10-4.
• Element Descriptors, one for each element reported. A different format of
Element Descriptor is used for each type of element, and data block size varies
by element type. Table 10-7 through Table 10-9 illustrate the Element Descriptors
for each element type.
Table 10-2: Read Element Status Command Field Values
Field Name
Field Location
Values
Allowed
Meaning
Byte Bit
VolTag 01 4 0 or 1
Set to 1 to have the library return bar code label (volume tag)
information.
Element Type
Code
01 3-0
0h
Return status for all element types. Note that the library does not
have an import/export element.
1h Return status only for medium transport elements (tape picker).
2h Return status only for storage elements (cartridge magazine slots).
4h Return status only for data transfer elements (tape drives).
Starting
Element
Address
02-03 All Any
The library only reports the status of elements at or above this
Starting Element Address, and of the type specified by the Element
Type Code.
DVCID 06 0
0 The library does not return device identifiers.
1 The library returns device identifiers if available.
Number of
Elements
04-05 All Any
The library sends descriptors for elements, not excluded by the
Element Type Code or Starting Element Address options, until it
sends the lesser of:
- all available element descriptors
- the number of element descriptors specified by Number of
Elements
- as many complete element descriptors as it can without
exceeding the number of bytes specified by Allocation Length
Allocation
Length
07-09 All Any