Test Unit Ready Command (00H) - Seagate Ultra160 Product Manual

SCSI Interface Product Manual, Rev. B
8.53

TEST UNIT READY command (00h)

The TEST UNIT READY command provides a means to verify the logical unit is ready. This is not a request for
a self-test. If the logical unit (drive) can accept an appropriate medium access command without returning
CHECK CONDITION status, the drive returns a GOOD status. See Table 241 for proper format.
Table 241: TEST UNIT READY command (00h)
Bit 7
Byte
0 0
0
1
LOGICAL UNIT NUMBER [1]
2 0
3 0
4 0
CONTROL [2]
5
[1] The LOGICAL UNIT NUMBER must be zero.
[2] See Table 61, "CONTROL field," in Section 7.2.1.
If the drive cannot become operational or is in a state such that a SCSI initiator port action (e.g., Start com-
mand) is required to make the unit ready, the drive returns CHECK CONDITION status with a Sense Key of
NOT READY. One of several possible additional sense codes indicates the reason for the NOT READY condi-
tion.
6 5
0 0
0 0
0 0
0 0
0 0
4 3
0 0
0 0
0 0
0 0
0 0
2 1
0 0
0 0
0 0
0 0
0 0
311
0
0
0
0
0
0