User's Guide

Chapter 2 Emulated Medium Changer SCSI Commands
Test Unit Ready (00h)
Quantum DX-Series Software Interface Guide 105
Test Unit Ready (00h) 2
The host uses the Test Unit Ready command to determine if a DX-Series
system is ready.
The DX-Series system responds in one of these ways, depending upon the
state of the DX-Series system:
•Returns a Good status - whenever the DX-Series system is ready to
accept a medium access command without returning a check
condition status it returns this status in response to a Test Unit
Ready command
• Returns a check condition status - when the DX-Series system
receives a Test Unit Ready command but is not ready to accept a
medium access command, it sets the Additional Sense fields and
returns this status
• The meaning of the values in the Additional Sense fields are
described along with the Request Sense command
The format for the Test Unit Ready command Descriptor Block is shown
in
table 69.
Table 69 Test Unit
Ready Command
Bit/Byte 7 6 5 4 3 2 1 0
0
1
2
3
4
5
• Logical Unit Number
The Logical Unit Number must be set to 0. This field indicates the
logical unit to which the message is sent.
Operation Code (00h)
Logical Unit Number Reserved (00h)
Reserved (000000h)
Reserved (00h)