User's Manual

DLT4000 SCSI Interface
8-34 DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem
8.4.8 LOG SENSE (4Dh)
Bit
7 6 5 4 3 2 1 0
0 Operation Code (4Dh)
1 Logical Unit Number (0) Reserved PPC SP(0)
Byte 2 PC Page Code
3 Reserved
4 Reserved
5 (MSB)
6 Parameter Pointer (LSB)
7 (MSB)
8 Allocation Length (LSB)
9 Unused Reserved Flag Link
Figure 8-17 LOG SENSED CDB
LOG SENSE allows the host to retrieve statistical information maintained by the
device about its own hardware or the installed media. It is a complementary command
to LOG SELECT.
PPC
The Parameter Pointer Control bit must be zero. A Parameter Pointer Control bit of
zero indicates that the parameter data requested from the device will start with the
parameter code specified in the Parameter Pointer field and return the number of bytes
specified in the Allocation Length field in ascending order of parameter codes from
the specified log page. A PPC bit of zero and a Parameter Point field of zero causes all
available parameter data for that page code to be returned to the initiator.
_________________________NOTE ____________________________
The current implementation of the Read/Write Compression Page does
not support a parameter pointer other than zero.
___________________________________________________________
If PPC bit is set or the Parameter Pointer is larger than the highest numbered
parameter on the page, then the target will terminate the command with CHECK
CONDITION status. The sense key is set to ILLEGAL REQUEST and the additional
sense code is set to INVALID FIELD IN CDB.
If the target does not support a parameter code within this page then it will not return
any data associated with this parameter.