Tandberg Data
Read
17-3
Tandberg SLR Product Line SCSI Functional Specifications
17.3. Exception Handling
17.3.1. General
See sections on Error Conditions For All Commands,
Deferred Errors, Error Conditions For Media Access
Commands and Buffer Parity Errors.
When the READ command has started to execute, all
detected errors will set the VADD bit and the
Information Bytes will hold the difference between the
requested and the actual Transfer Length. See the
following sections for details.
If the FIX bit is one and the Drive is in Variable Block
mode, the READ command will be terminated with CHECK
CONDITION. The Error Code will be set to I
NVALID FIELD IN
CDB. No data will be transferred.
If both the SILI and the FIX bits are one, the Drive
will terminate the READ command with CHECK CONDITION
status. The Error Code will be set I
NVALID FIELD IN
CDB.
17.3.2. No Data
If the Drive is not able to find data on the inserted
cartridge the READ command will be terminated with CHECK
CONDITION. When using a SLRtape140, SLRtape100,
SLRtape75, SLRtape60, SLRtape50, SLRtape40, SLR32 or
SLRtape24 medium the Error Code will be End-of-data
detected. When using a SLRtape7, SLR5 or DC9250 medium
there are two possible error codes. If the medium is
physically blank (bulk erased etc.) the Error Code will
be End-of-Data Detected or Recorded entity not found.
Otherwise the Error Code will be End-of-data detected.
In any case the Valid (VADD) bit in the sense data list
will be set to one. The Information Bytes will be set
equal to the requested Transfer Length.
17.3.3. Tapemark Detected
If a tapemark (Filemark or Setmark) is encountered
during execution of a READ command, the command will
transfer all data up to the tapemark. The READ command
will then be terminated with CHECK CONDITION status. If
a Filemark is encountered, the Error Code is set to
F
ILEMARK DETECTED
. If a Setmark is encountered, the Error
Code is set to S
ETMARK DETECTED
. For both errors the
Filemark (FMK) bit and the Valid (VADD) bit in the sense
data list will be set to one. The Information Bytes will
be set to the difference (residue) between the requested
Transfer Length and the actual transfer length (bytes or
blocks). For variable length reads the Information Bytes
will be set equal to the Transfer Length (because a
tapemark block was found instead of a data block and no
data was transferred). When the command has terminated,
the logical tape position will be located after the
tapemark (end-of-media side).
