DLT1/VS80 SCSI Interface Guide
81-81276-01 Rev A01
July 2004
4-17
Table 4-9.
LOG SELECT (4Ch) Command Descriptor Block — Field Descriptions
Field Name
Description
LUN
Logical Unit Number. The target ignores this field. Only an IDENTIFY message
can change the LUN.
PCR
Parameter Code Reset. If this bit is 1 and the Parameter List Length field is 0, all
accumulated values of page codes 2, 3, and 32 are 0 and all threshold values are
default. If PCR is 1 and the Parameter List Length field is a non-zero value, the
tape drive terminates the command with CHECK CONDITION status, Sense Key
set to ILLEGAL REQUEST, and Additional Sense Code (ASC) set to INVALID
FIELD IN CDB.
SP
Save Page. The tape drive does not support this bit and sets it to 0. If the SP bit
is 1, the tape drive terminates the command with CHECK CONDITION status,
Sense Key of ILLEGAL REQUEST, and ASC of INVALID FIELD IN CDB.
PC
Page Control. This field defines the type of parameter values to be selected.
Code
00b
01b
10b
11b
Type of Parameter Values
Threshold Values
Cumulative Values
Default Threshold Values
Default Cumulative Values
When the PC field is 00b or 01b and the Parameter List Length field is 0, the tape
drive terminates the command 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 10b and the Parameter List Length field is 0, then all current
Threshold Values are reset to the Default Threshold Values. This is equivalent to
no change, since Threshold Values cannot be modified.
When the PC field is 11b and the Parameter List Length field is 0, then all current
Cumulative Values are reset to the Default Cumulative Values. This is equivalent
to clearing all log pages that 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 0 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 elsewhere in this section).
Summary of Contents for DLTtape DLT1
Page 1: ...DLT1 VS80 SCSI Interface Guide...
Page 6: ...DLT1 VS80 SCSI Interface Guide vi July 2004 81 81276 01 Rev A01 Notes...
Page 12: ...Table of Contents xii July 2004 81 81276 01 Rev A01 Notes...
Page 16: ...List of Figures xiv July 2004 81 81276 01 Rev A01 Notes...
Page 20: ...List of Tables xviii July 2004 81 81276 01 Rev A01 Notes...
Page 24: ...Chapter 1 Introduction 1 4 July 2004 81 81276 01 Rev A01 Notes...
Page 32: ...Chapter 2 General SCSI Bus Operation 2 8 July 2004 81 81276 01 Rev A01 Notes...
Page 42: ...Chapter 3 SCSI Messages 3 10 July 2004 81 81276 01 Rev A01 Notes...
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