User's Guide

Commands: Read Element Status (B8h) Page 115
The following example illustrates the data structure returned for a 12-slot magazine.
Element Status Data (8-byte header)
Medium Transport Element (changer) Page (8-byte header)
Medium Transport element Descriptor (12 bytes)
Storage element Page (8-byte header)
Storage Element Descriptors
(12 bytes each; for a six-slot magazine=72 bytes)
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Data Transfer Element (drive) Page (8-byte header)
Data Transfer Element Descriptor (12 bytes)
Element Status Data Header
The following table shows the header for the element status data returned from the
drive.
Byte
Bits
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 0
1 First element Address Reported
2 MSB Number of elements available
3 LSB Number of elements available
4 0 0 0 0 0 0 0 0
5 MSB—Byte Count of Report Available
6 Byte Count of Report Available
7 Byte Count of Report Available—LSB
8 Element Status Page
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n Element Status Page
The first element address reported field indicates the element address of the
element with the smallest element address found to meet the CDB request. Refer to
the MOVE MEDIUM command for the addresses of the various elements.
The number of elements field indicates the number of elements meeting the request
in the CDB. The status for these elements is returned if sufficient allocation length is
specified.
The byte count of report available field indicates the number of bytes of element
status page and descriptor data available for all elements meeting the request in the
CDB. This value is not adjusted to match the allocation length available.
Element Status Page Header
Each of the three Autoloader element status pages includes an 8-byte header
followed by one or more element descriptors. The following table shows the header
for an element status page.