Chapter 4: SCSI Commands
4-92
July 2004
81-81276-01 Rev A01
4.15 READ POSITION (34h)
The READ POSITION command reads a position identifier or SCSI Logical Block Address. The
LOCATE command uses this identifier to position the medium to this same logical position in a high-
performance fashion.
Figure 4-63.
READ POSITION (34h) Command Descriptor Block — Data Format
N
OTE
:
The tape drive returns CHECK CONDITION with the UNIT NOT
READY Sense Key with the READ POSITION command if the media is
not ready to be accessed.
Bit
Byte
7
6
5
4
3
2
1
0
0
Operation Code (34h)
1
Logical Unit Number
Reserved
BT
2 - 8
Reserved
9
Unused
Reserved
Flag
Link
Table 4-55.
READ POSITION (34h) 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.
BT
Block Type. This bit indicates how the position is interpreted. Since the tape drive
uses the same logical block address whether this bit is set or not, it ignores setting
BT. The logical block address values include all recorded objects: blocks and
filemarks.
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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