Specifications

ATAPI For Streaming Tape QIC-157 Rev B
96
6.8.14. TEST UNIT READY Command
The TEST UNIT READY command provides a means to check if the Device is ready. This is not a
request for a self-test. If the Device would accept an appropriate medium-access command without
returning “Check Condition” status, this command shall return a “Good” status. If the Device cannot
become operational or is in a state such that Host action is required to make the unit ready, the
Device shall return “Check Condition” status with a Sense Key of NOT READY.
Table 6-74 Test Unit Ready Command
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation code (00h)
1 Reserved
2 Reserved
3 Reserved
4 Reserved
5 Reserved
6 Reserved
7 Reserved
8 Reserved
9 Reserved
10 Reserved
11 Reserved
6.8.14.9. Using the TEST UNIT READY Command
The TEST UNIT READY command is useful in that it allows the Host to poll a Device until it is
ready without the need to allocate space for returned data. It is especially useful to check cartridge
status. ATAPI Devices are expected to respond promptly to indicate the current status of the
Device.
Table 6-75 Recommended Sense Key, ASC and ASCQ for TEST UNIT READY Errors
Sense Key ASC ASCQ Description of Error
00 00 00 NO ADDITIONAL SENSE INFORMATION
05 20 00 INVALID COMMAND OPERATION CODE
05 24 00 INVALID FIELD IN COMMAND PACKET
02 04 00 NOT READY - CAUSE NOT REPORTABLE
02 04 01 NOT READY - IN PROGRESS OF BECOMING READY
02 04 02 NOT READY - INITIALIZING COMMAND REQUIRED
02 04 03 NOT READY - MANUAL INTERVENTION REQUIRED
02 04 04 NOT READY - FORMAT IN PROGRESS
02 3A 00 MEDIUM NOT PRESENT
03 - - Deferred medium error
06 28 00 NOT READY TO READY TRANSITION
06 29 00 POWER ON, RESET, OR ATAPI SOFT RESET OCCURRED
06 2A 01 MODE PARAMETERS CHANGED