Operating instructions

20-4
SCSI REFERENCE 1012975
CHAPTER 20—RESERVE (16h OR 56h)
20.2.2 ELEMENT LIST DESCRIPTOR
After sending the RESERVE CDB, you send zero or more Element List
Descriptors to reserve specific autoloader elements.
Number of Elements – Bytes 02 and 03
This field allows you to specify the number of elements to be reserved. If you
specify 0 for this field, all elements starting at the Element Address (bytes 04
and 05) through the last element address for the autoloader are reserved.
Element Address – Bytes 04 and 05
This field allows you to specify the element or the starting address of a series
of elements to be reserved. See Figure 2-1 on page 2-3 for the default element
addresses for the autoloader.
20.2.3 TEN-BYTE CDB (PAGE CODE 56h)
The ten-byte CDB can only be used to reserve the autoloader as a unit. To
reserve only specified elements, use the six-byte CDB.
LongID – Byte 01, Bit 1
The value for this field must always be 0, indicating that the autoloader does
not support device IDs greater than 255.
Element – Byte 01, Bit 0
Element reservations are not supported in the 10-byte RESERVE CDB. The
value for this field must always be 0. Use the 6-byte RESERVE CDB to reserve
specific elements within the autoloader.
Reservation Identification – Byte 02
Element reservations are not supported in the 10-byte RESERVE CDB. The
autoloader ignores this field. Use the 6-byte RESERVE CDB to reserve specific
elements within the autoloader.
Bit
Byte
7 6 5 4 3 2 1 0
00
Reserved
01
02 (MSB)
Number of Elements
(LSB)
03
04 (MSB)
Element Address
(LSB)
05