Status/Error Reporting - Quantum DLT 8000 Product Manual

5.1.3 Status/Error Reporting

SCSI message-level errors are communicated by messages that are defined specifically for
that purpose (for example, MESSAGE PARITY ERROR, MESSAGE REJECT). Message-
level errors are also handled by drive-managed retries. Refer to Chapter 4 for more
detailed message-handling information.
SCSI command-level errors are communicated by a status code that is returned by the
drive during the STATUS phase. This phase occurs at the end of each command, unless
the command is terminated by one of the following events:
ABORT message
BUS DEVICE RESET message
Hard reset condition
Unexpected disconnect
The status code is contained in bits 1 through 5 of the status byte. Bits 0, 6, and 7 are
reserved. Table 5–4 describes the status codes returned by the drive.
Status
Code Definition
00h GOOD
02h CHECK CONDITION
08h BUSY
10h INTERMEDIATE GOOD
18h RESERVATIONCONFLICT
Table 5–4 Status Codes
Meaning
The drive successfully completed the command.
A Contingent Allegiance condition occurred.
The drive cannot service the command at the
moment, and its Command Descriptor Block has
been discarded. The initiator can retry the command
at a later time.
This status is returned instead of a GOOD status for
commands issued with the LINK bit set. Following
the return of this status, the drive proceeds to the
COMMAND phase for the transfer of the next linked
command.
Another initiator has reserved the drive when it has
been reserved for another initiator with a RESERVE
UNIT command (this status is never returned for
INQUIRY or REQUEST SENSE commands).
Quantum DLT 8000 Tape System
SCSI Commands
5-7