SCSI Commands: 20BLOG SELECT
Page
44
3.8
LOG SELECT
The LOG SELECT and LOG SENSE commands work in conjunction to allow the
host to control and obtain statistical information about cartridge usage and error
rates. This information consists of counters of particular events.
The LOG SELECT command is used to reset the log counters to their default
values. A SCSI Bus Reset, Bus Device Reset, or cartridge loading is also used to
reset these counters (of pages 02h, 03h, 0Ch, and 32h.) Multiple pages are reset by
a single LOG SELECT command. LOG SELECT affects pages 02h, 03h, 2Eh, and
32h only. See LOG SENSE for information about log pages and their format.
3.8.1
LOG SELECT Command Descriptor Block
Byte
Bits
7 6 5 4 3 2 1 0
0
Operation Code (4Ch)
1
Ignored LUN
Reserved
PCR
Rsvd
2
PC Reserved
3
Reserved
4
Reserved
5
Reserved
6
Reserved
7
(MSB)
8
Parameter List Length
(LSB)
9
Control
3.8.1.1
LOG SELECT Command Field Descriptions
Field
Bytes
Bits
Description
Operation
Code
0
The Operation Code for LOG SELECT is 4Ch
Ignored
Logical
Unit
1
5-7
The LUN field is vestigial from the SCSI-1 standard and is ignored.
Parameter
Code
Reset
(PCR)
1 1
0 = Reset values as specified by PC. Do not clear the DU (Disable
Update, see Log Parameter) bits of the parameters of log pages
02h, 03h, 2Eh, and 32h. With page 2Eh log parameters are set to
0 only when PC = 11b.
1 = Reset log parameters on pages 02h, 03h, 2Eh, and 32h. All
accumulated values are set to 0; all threshold values are set to
maximums except page 2Eh. DU bits of the parameters of these
log pages are also cleared.
Page
Control
(PC)
2
6-7
00b = Check Condition if Parameter List Length > 0.
01b = Check Condition if Parameter List Length > 0.
10b = All thresholds are set to maximums. Check Condition if
Parameter List Length > 0.
11b = All accumulated values are set to 0. Check Condition if
Parameter List Length > 0.
This field is ignored if PCR is not 0.
Summary of Contents for LTO 4
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