Tandberg Data SLR7-140 PROGRAMMER, Руководство пользователя

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Tandberg Data Read Position
20-4 Tandberg SLR Product Line SCSI Functional Specifications
BPU
The block position unknown (BPU) bit is set when the
block position is not known and cannot be obtained
without tape motion. The remainder of the data in the
parameter list will not be valid. The block position may
be unknown when using mediums without any recorded tape
map information. On SLR5 and DC9520 type media tape map
information is optional (it may or may not exist on a
given tape). Tape map information is always present on
SLRtape140 to SLRtape7 or SLR32 media. Note however that
the Drive will generate its own tape map information
when given the opportunity (when moving sequentially
from BOP to EOP on each partition). When using LOCATE
physical or SPACE to EOD, the Drive will not be able to
generate complete tape map information and the BPU-bit
will most likely be set in the parameter list of a
subsequent READ POSITION command.
While the Drive is processing an immediate command, the
BPU bit will be set to one.
PERR
The Position Error (PERR) bit will be zero to indicate
that there is no overflow in any of the returned
position data fields.
Partition Number
The partition number indicates the current partition
number.
First Block
Location
The first block location field indicates the position of
the next data block to be transferred between the
Initiator and the Drive's data buffer if the previous
command was a READ, VERIFY
1
or WRITE command. When the
medium is positioned at BOP, the value returned will be
0.
Last Block Location
The last block location field will always be set to
zero.
Number of Blocks
in Buffer
The number of blocks in buffer field will always be set
to zero.
Number of Bytes in
Buffer
The number of bytes in buffer field will always be set
to zero.
20.4. Exception Handling
See sections on Error Conditions For All Commands and
Deferred Errors.
If the TCLP and LONG bits are not set to zero the
command will be terminated with CHECK CONDITION status.
The error code will be set to I
NVALID FIELD IN
CDB.
If the BT bit is set to one when using a SLRtape140 to
SLRtape7 or SLR32, medium, the READ POSITION command
will be terminated with CHECK CONDITION status. No
parameter date will be transferred. The Error Code will
be set to Invalid field in CDB.
1
VERIFY is not supported by SLR7 and SLR140