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Chapter 8 SCSI Commands
The Return/Count/Test Flag Number field has two different applications. When
the TEST bit is 0, the MODE SELECT command indicates the Report Counter
in this field. Because the Report Counter field is not supported by the
autoloader, the command terminates with a CHECK CONDITION status, and
the sense key is ILLEGAL REQUEST when the TEST bit is 0. When the TEST
bit is 1, the MODE SELECT command indicates the Test Flag Number in this
field. This is never returned in response to the MODE SENSE command. Valid
values of Test Numbers are from -64 to 64 and 32767 (7FFFh). Negative
numbers are represented by twos complement notation. When the Test Flag
Number value is not valid, the MODE SELECT command terminates with a
CHECK CONDITION status, the sense key is ILLEGAL REQUEST, and ASC/
ASCQ is INVALID IN PARAMETER LIST.
When a valid Test Flag Number is set and it is a positive number, its Tape Alert
Flag is set. However, when it is a negative number, its Tape Alert Flag is
cleared.
Here, the Test Flag Number indicates the Tape Alert number of the LOG
SENSES command, and the corresponding Tape Alert Flag is set if the value is
positive, cleared if the value is negative. For 32767, all Tape Alert Flags are
cleared.
This page is for specific to TapeAlert operations and access to this page is not a
condition for the generation of a Unit Attention.
8.5.3. Configuration Page
The Configuration Page is used to specify and return autoloader special
operation specifications.
Table 8.5.3.1 : Configuration Page
The Parameters Savable (PS) bit is used by the MODE SENSE command, but
with the MODE SELECT command it is reserved. A PS bit of 1 indicates that
there is a function to save this Mode Page in non-volatile memory. The data of
this Mode Page is fixed and therefore the PS bit is always 0.
The Parity bit specifies whether to check the SCSI bus parity. The following
specifications exist.
0: Do not check the SCSI bus parity.
1: Check the SCSI bus parity (default).
Maximum Parity Retries specifies the maximum number of retries after a parity
error occurs in the Command Out Phase, Message Out Phase, or Data Out
Phase. This field can be any value between 0 and 255. 0 indicates no retries. The
default autoloader value is 1.
Bit
Byte
7
6
5
4
3
2
1
0
0
PS(0)
Reserved
Page Code(00h)
1
Page Length(02h)
2
Reserved(0)
Parity
Reserved(0)
3
Maximum Parity Retries
