User`s guide

Chapter 4 SCSI Interface
SCSI Message System
56 ATL PowerStor L200 Series Library User’s Guide
SCSI Message System
4
The message system allows an initiator and a target to communicate
for the purpose of physical path management.
To support certain SCSI-1 initiators, the library does not require an
Identify message. If a message is sent by the initiator after the
SELECTION
phase, it should be an
IDENTIFY
,
ABORT
, or
BUS DEVICE
RESET
message. In this case, if the library recovers a message other
than those listed above, it will go directly to
BUS FREE
phase.
Table 11 lists SCSI messages that are supported:
Table 11 Supported SCSI
Messages
Message
Operation
Code In/Out
Abort
06h Out
Abort Tag
0Dh Out
Bus Device Reset
0Ch Out
Clear Queue
0Eh Out
Command Complete
00h In
Disconnect
04h In
Extended Message
(SDTR and Wide
Data Transfer
Request. 16-bit wide
SCSI option only.)
01h Both
Identify
80h-FFh Both
Initiator
Detected Error
05h Out
Linked Command
Complete
0Ah In
Linked Command
Complete w/flag
0Bh In
Message Parity
Error
09h Out
Message Reject
07h Both