Test Unit Ready - 00h
What the Library Does With This Command
The library returns status based on its current mode and state. These are defined in the following table.
Table 1: Test Unit Ready statuses
|
Mode |
State |
Status |
|
Online |
Ready |
Good |
|
Online |
Not Ready |
Check Condition |
|
Offline |
Ready |
Check Condition |
|
Offline |
Not Ready |
Check Condition |
Any time a Not Ready condition or a Unit Attention is pending, a check condition status will be encountered. The various types of Not Ready and Unit Attention conditions are listed in the Request Sense command section in Request Sense - 03h.
Command Usage
The TEST UNIT READY command allows the initiator to verify that the library is ready to accept commands or perform motion tasks. It is a suitable command for general polling to monitor the library, and receive information via Unit Attentions on any changes within the library.
Test Unit Ready CDB Format
The TEST UNIT READY CDB format is shown in the following table.
Table 2: TEST UNIT READY CDB format
|
Bit Byte |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
0 |
Op Code (00h) |
|||||||
|
1 |
Logical Unit Number |
Reserved |
||||||
|
2 |
Reserved |
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|
3 |
Reserved |
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|
4 |
Reserved |
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|
5 |
Control |
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