M2488 PRODUCT GUIDE MEDIA CHANGER COMMANDS
March 1997 CG00000-011503 REV. A 6-19
6-2.5 READ ELEMENT STATUS MC command B8h
The READ ELEMENT STATUS medium changer command requests that the target report status
information for the medium-changer elements. Status for the elements is returned in blocks of bytes
called element descriptors, one descriptor per element.
This command can be used to determine which elements are defined and the state of each defined
element. The READ ELEMENT STATUS command is typically used preceding a MOVE MEDIUM
or EXCHANGE MEDIUM command to help determine if a move or exchange operation is possible.
6-2.5.1 READ ELEMENT STATUS CDB Description
READ ELEMENT STATUS is a twelve-byte command. The bytes are shown below and
described in Table 6-4. Common fields are described in paragraph 4-3.1 on page 4-4.
BITS
BYTES 7 6 5 4 3 2 1 0
0
1 0 1 1 1 0 0 0
1
LUN Reserved Element Type Code
2-
3
MSB
Starting Element Address
LSB
4-
5
MSB
Number of Elements
LSB
6
Reserved
7-
9
MSB
Allocation Length
LSB
10
Reserved
11
Reserved Flag Link
Note: Changeable fields in the CDB are shaded.
