M2488 PRODUCT GUIDE TAPE UNIT SCSI COMMANDS
April 1997 CG00000-011503 REV. A 4-5
4-3.2 CHANGE DEFINITION command 40h
The CHANGE DEFINITION command is used to modify the operating definition of the selected tar-
get with respect to all initiators. This command is executed even if the Magnetic Tape Unit (MTU) is
NOT READY. It is not executed if the selected LUN is nonexistent. This command is used in con-
junction with the INQUIRY command to change (and optionally save) parameters that affect the
operation of the target.
4-3.2.1 CHANGE DEFINI TION CDB Desc ription
CHANGE DEFINITION is a ten-byte command. The bytes are shown below and described in
Table 4-3. Common fields are described in paragraph 4-3.1 on page 4-4.
BITS
BYTES 7 6 5 4 3 2 1 0
00 1 0 0 0 0 0 0
1LUN Reserved
2Reserved Save
30Definition Parameters
4
Reserved
5
6
7
8Parameter Data Length
9Reserved Flag Link
Note: Changeable fields in the CDB are shaded.
Table 4-3. CHANGE DEFINITION Field Description
BYTE BIT VALUE DESCRIPTION
0 0-7 40h Operation code.
2 0 0
1A Save control bit of zero indicates that the target shall not save the operating definition.
A Save bit of one indicates that the target shall save the operating definition to non-volatile
memory.
This target will not apply the new parameters until a power cycle is performed, so sending
a Save bit of zero is a means of performing a parameter validity check.
3 0-6 See Table 4-4 for a description of the Definition Parameter field.