Append Error; Phase Sequencing - Tandberg Data SLR7-140 PROGRAMMER Manual

<sequence 1>
<sequence 2>
<sequence 3>
Tandberg Data
30.8.9.

Append Error

If the WRITE command is executed after READ, LOCATE,
SPACE or VERIFY command or after a WRITE command where
the data in the drive internal buffer has been flushed
to the tape, the Drive must seek the last block on the
tape before the write operation starts. In all these
situations an End Of Data marker will identify where the
last block transferred is located on the tape. If this
seek operation fails, the Drive will terminate the WRITE
command with a CHECK CONDITION status. The Error Code
will be set to W
RITE APPEND POSITION
will be set to MEDIA ERROR. The Valid (VADD) bit will be
set to one.
The Information Bytes in the sense data list will be set
as described in Section 30.5.5.
The EOD marker
consecutive read operations to terminate with E
D .
ETECTED
The Append Error condition has priority over the Logical
Early Warning error condition.
Additional WRITE commands issued after a non-recoverable
write error has occurred, will be terminated immediately
with a CHECK CONDITION (no data will be transferred).
The append error condition will persist until a position
type command has been executed (ERASE, LOAD/UNLOAD or
REWIND).

30.9. Phase Sequencing

In this section the possible SCSI-bus phase sequences
during execution of the WRITE command are described.
Section 3.2.1 has more details about the generic phases
in the brackets.
:= <initiator-part> <message-out> <command> <disconnect> <reconnect>
<completed>
This sequence will be used when an error is detected
during the initial part of the WRITE command or when the
Transfer Length is zero.
:= <initiator-part> <message-out> <command>{<disconnect> <reconnect>
<data-out>}<completed>
This sequence will be used when the Drive is configured
to buffered mode and the WRITE command terminates with
GOOD STATUS.
The Drive will first disconnect when the CDB has been
transferred. The Drive will reconnect when there is room
in the data buffer for at least the number of bytes
specified by the Write Buffer Empty Ratio. The Drive
will disconnect to make sure that the burst size never
exceeds the number of bytes specified by the Maximum
Burst Size. Note, the Drive will not disconnect after
the last data burst.
:= <initiator-part> <message-out> <command>{<disconnect> <reconnect>
<data-out>}<disconnect> <reconnect> <completed>
This sequence will be used when the Drive is configured
to unbuffered mode
during the WRITE operation.
The sequence is equal to <sequence 2> except that the
Drive will disconnect after the last data burst.
30-8 Tandberg SLR Product Line SCSI Functional Specifications
error and the Sense Key
will reside on
or when an
the tape, ensuring
O
ND
error is encountered
Write
D
F ATA