User's Guide

84 SCSI Commands
Element Type Code - This field specifies the element types selected for the returned information, as shown
in the following table.
Starting Element Address - This field specifies the minimum element address to report. Only elements
with an element type code specified by the Element Type Code field, and with an address greater than or
equal to the starting element address will be reported. The starting element address must be a valid element
address, but not have to be within the range specified by the Element Type Code field.
Number of Elements - This field specifies the maximum number of element descriptors to return. Only
those descriptors that can be completely transferred within the allotted allocation length will be returned.
Allocation Length - This field specifies the byte length allowed for returned element descriptors. Only
complete element descriptors are returned. The library returns element descriptors until one of the following
conditions are met:
• All available element descriptors have been returned
• The number of element descriptors specified in the Number of Elements field have been returned
• The number of bytes specified in the Allocation Length field have been returned
• There is less allocation length space available than is required by the next complete element
descriptor
Request Volume Element Address Response
Element status data consists of an eight-byte header, followed by one or more element status pages (per
element type). Each element status page consists of a header, followed by one or more element descriptor
blocks. A complete response then looks like:
Element Status Header
Element Status Page Header (first element type)
Element Descriptor
…(more descriptors)…
Element Descriptor
…(more status pages)…
Element Status Page Header (next element type)
Element Descriptor
…
Element Descriptor
Table 80 Element Type Code
Code Selected Element Type
0000b (0) All element types reported
0001b (1) Medium transport element (accessor)
0010b (2) Storage element
0011b (3) Import/Export element
0100b (4) Data transfer element (drives)