Test Unit Ready - 00h

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.

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.

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 : 4	Reserved
5	Control