MEDIA CHANGE R COMMANDS M2488 PRODUCT GUIDE
6-20 CG00000-011503 REV. A March 1997Table 6-17. READ ELEMENT STATUS Field Description
BYTE BIT VALU
EDESCRIPTION
0 0-7 B8h Operation code.
1 0-3 The Element type code field specifies an element type; element descriptors are only
returned for those elements that are of the same type as specified by this field.
Table 6-18 shows the codes used for the Element type code field. The special value 0h
can be used in the Element type code field when element descriptors for all element
types are to be reported. If any reserved value (05h to 0Fh) is used in the Element type
code field, then no data is sent and CHECK CONDITION status will be reported. The
sense data for this error will contain a sense key of ILLEGAL REQUEST.
2-3 The Starting element address field specifies a minimum element address; element
descriptors are only returned for those elements with addresses greater than or equal
to the value in this field. The defined element addresses for the Flush-Mount Car-
tridge Loader (FACL) and Automatic Cartridge Loader (ACL) are shown in Table 6-
19
4-5 The Number of elements field specifies a maximum number of element descriptors to
be reported. If the set of element descriptors to be reported as defined by the Element
type code field and Starting element address field contains more element descriptors
than are allowed to be reported by the Number of elements field then only a subset of
these element descriptors will be reported. Which elements are chosen for this subset
is not specified.
7-9 The Allocation length field describes the maximum number of bytes that are to be
transferred for the READ ELEMENT STATUS command. If the allocation length is
not sufficient to transfer all element descriptors to be reported then the target transfers
as many bytes as possible stopping at the end of a full element descriptor. It is not
considered an error if the value in the Allocation length field is zero or is not suffi-
cient to transfer all element descriptors to be reported.
Given a sufficient allocation length, element descriptors will be reported for all
defined elements if the Element type code is 0h, the Starting element address is 0 and
the Number of elements is FFFFh.
All reserved fields of the CDB should be set to 0. If any reserved field is set to a non-
zero value then CHECK CONDITION status is reported. The sense data for this error
will contain a sense key of ILLEGAL REQUEST.
Table 6-18. Element Type Codes
CODE DESCRIPTION
0h All element types reported
1h Medium Transport Element
2h Storage Element
3h Import Export Element
4h Data Transfer Element
5h-Fh Reserved