User's Manual

DLT4000 SCSI Interface
DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 8-29
PC Type of Parameter Values
00b Threshold Values
01b Cumulative Values
10b Default Threshold Values
11b Default Cumulative Values
Figure 8-13 LOG Page Control Definitions
All types of parameter values are changeable through Log Select.
When the PC field is set to 00b or 01b and the Parameter List Length is zero, the
command is terminated with a CHECK CONDITION Status, with Sense Key of
ILLEGAL REQUEST, and ASC of INVALID FIELD IN CDB. This is because
modification of Current Threshold Values and Current Cumulative Values is not
supported.
When the PC field is set to 10b and the Parameter List Length field is 0 then all
Current Threshold Values will be reset to the Default Threshold Values. This is
equivalent to no change as Threshold Values cannot be modified.
When the PC field is set to 11b and the Parameter List Length field is 0 then all
Current Cumulative Values will be reset to the Default Cumulative Values. This is
equivalent to clearing all log pages which can be cleared.
Parameter List Length
This field specifies the length in bytes of the LOG SELECT parameter list to be
transferred from the initiator to the target during the DATA OUT phase. A parameter
list length of zero indicates that no data is to be transferred. This condition is not
considered an error (see the description of Parameter Code Reset and Page Control
fields in this section).
Error Detection Summary in LOG SELECT CDB
The following conditions constitute errors that will be detected by the drive in relation
to the CDB. The request sense data is set to ILLEGAL REQUEST, INVALID FIELD
IN CDB.
• If PCR bit is set to 1 and parameter list length is not zero
• If SP bit is set 1
• A parameter list length that would cause a parameter within a valid page to be
truncated or otherwise incompletely initialized.