Tandberg Data SLR7-140 PROGRAMMER Manual page 277

Tandberg Data
Fixed Block Mode
When the Block Size field in the Block Descriptor
List of the MODE SELECT command is different from
zero (Fixed Block mode), the READ command will then
be terminated with CHECK CONDITION status if the
Transfer Length is less then the actual block length
recorded on the tape even if the SILI bit is set to
one. The Error Code will be set to N
,
INFORMATION ILLEGAL LENGTH BLOCK READ
indicator (ILI) and Valid (VADD) bits in the sense
data list will be set to one. The Information Bytes
will be set to the requested Transfer Length minus
the actual block length (a negative number). This
means that the absolute value of the Information
Bytes indicates the number of byte not transferred
from the block read. When the command has terminated,
the logical tape position will be located after the
incorrect length block (end of partition side).
Variable Block Mode
When the Block Size field in the Block Descriptor
List of the
(Variable Block mode), a SILI bit of one indicates
that the Drive will not return CHECK CONDITION status
if the only error is that the Transfer Length does
not match the actual block length recorded on the
tape. When the command has terminated, the logical
tape position will be located after the incorrect
length block (end of partition side).
17.3.4.2. FIX Bit Set to ONE
If the actual block length (length of block found on the
tape) is smaller than the configured Block Size (see
MODE SELECT command), only the actual block length is
transferred. If the actual block length is larger than
the configured Block Size, only the configured Block
Size is transferred.
The READ command will then be terminated with CHECK
CONDITION status.
ADDITIONAL SENSE INFORMATION
illegal length indicator (ILI) and Valid (VADD) bits in
the sense data list will be set to one. The Information
Bytes will be set to the requested Transfer Length minus
the actual number of blocks transferred (not including
the incorrect
unexpected length is not counted among the transferred
blocks. When the command has terminated, the logical
tape position will be located after the incorrect length
block (end of partition side).
17.3.4.3. Illegal Length Summary
The table shown
handling. The
Underlength when the Transfer Length is larger than the
actual block length.
shown Overlength when the Transfer Length is less than
the actual block length.
17-5 Tandberg SLR Product Line SCSI Functional Specifications
MODE SELECT command
The Error Code
,
ILLEGAL
length block).
below summarizes
Illegal Length
The Illegal
O ADDITIONAL SENSE
. The illegal length
is set to
will be set
.
LENGTH BLOCK READ
The block with
the illegal length
Type column
Length Type column
Read
zero
to N
O
The
the
shows