User's Manual

DLT2000 SCSI Interface
8-122 DLT2000/DLT2700 Cartridge Tape Subsystem
8.4.23 TEST UNIT READY (00h)
Bit
76543210
0 Operation Code (00h)
Logical Unit Number Reserved
Reserved
Byte
Unused Flag Link
1
Reserved
2
Reserved
3
Reserved
4
5
Figure 8-77 TEST UNIT READY CDB
TEST UNIT READY checks if the drive unit is ready for commands involving tape
movement. If the drive has a tape loaded, the command returns a GOOD status.
Otherwise, CHECK CONDITION is reported.
It is possible to get multiple check conditions on a TEST UNIT READY command
because of power cycle, code update, and tape loaded.
8.4.23.1 Medium Changer Considerations
When directed at the Media Loader LUN, this command will return Check Condition,
Sense Key, or Not Ready if:
• The Mode Select key switch is in the Service mode, and there is no 24V signal
(usually means the loader assembly has been moved out of its sleeve enough to trip
the 24V interlock.)