SCSI Commands: 21BLOG SENSE
Page
49
Field Bytes
Bits
Description
Page
Code
2
0-5
00h = Requests Supported Log Pages Log
02h = Requests Write Error Counters Log
03h = Requests Read Error Counters Log
0Ch = Requests Sequential Access Device Log
0Dh = Requests Temperature Log
12h = Requests Tape Alert Response Log
14h = Requests Device Statistics Log
16h = Requests Tape Diagnostic Log
18h = Requests Protocol Specific Port Log (SAS only)
2Eh = Requests TapeAlert Log
30h = Requests Tape Usage Log
31h = Requests Tape Capacity Log
32h = Requests Data Compression Log
33h = Requests Error Events Log
3Eh = Requests Tape Device Statistics Log
Parameter
Pointer
5-6 7-0
Specifies the beginning parameter code to be returned to the initiator.
All remaining parameter codes are returned in ascending order.
This field is ignored for page code 00h.
Allocation
Length
7-8 7-0
The Allocation Length field specifies the maximum amount of
memory space (in bytes), which the initiator has reserved for LOG
SENSE data.
The drive returns the number of bytes contained in the requested
page, or the requested Allocation Length, whichever is less. If the
Allocation Length is less than the actual page length, the transfer is
truncated.
Reserved
All reserved bits must be 0.
Control 9
See
SCSI Command Control Byte Format on page 25.
The Page Control (PC) field specifies the type of counters that the initiator is
requesting. The value 01b is the most common page control setting. This requests
the accumulated counts for the page to be returned. These counts reflect the current
count of events since the last power-on cycle, SCSI bus Reset, Bus Device Reset,
Target or Logical Unit Reset, Reset LIP, cartridge loading, or the last LOG SELECT
command that cleared the parameter values.
Accumulated values are incremented by the drive as an event occurs. For pages
02h, 03h, and 32h, these values can be cleared with all the above methods. For
page 0Ch these values can be cleared with all the above methods except with LOG
SELECT. Because the drive maintains the accumulated values in volatile memory,
the values may be lost if a power cycle occurs.
The PC field is ignored for pages 00h, 0Ch, 0Dh, 12h, 14h, 16h, 18h, 2Eh, 30h, 31h,
33h, and 3Eh and the accumulated values are always returned except page 00h,
which has no accumulated values.
3.9.2
Log Sense Parameter Pointer Field
The Parameter Pointer field specifies the starting page parameter that is to be
transferred. For example, if the page uses parameter codes 2 through 6 and the
parameter pointer field is set to 3, then the drive returns parameters 3 through 6.
Likewise, if the parameter pointer is set to 1, parameters 2 through 6 are returned.
Summary of Contents for LTO 4
Page 1: ......
