Descriptor Mode (03H); Read Data From Echo Buffer (0Ah); Figure 131 Read Buffer Descriptor - Data Format - Quantum DLT S4 Reference Manual

Descriptor Mode (03h)

Figure 131 READ BUFFER
Descriptor — Data Format
Bit
7
Byte
0
(MSB)
1 — 3
Read Data from Echo
Buffer (0Ah)
DLT-S4 Interface Reference Guide
4
In this mode, the drive returns a maximum of 4 bytes of
descriptor information. The drive returns the descriptor information for
the buffer specified by the Buffer ID. In this mode, the drive does not
reject the invalid Buffer IDs with a
all zeros in the
READ BUFFER
indicating that buffer offsets should be integral multiples of 8.
6 5
In this mode the drive transfers data to the application client from the
4
Echo Buffer. The Echo Buffer transfers the same data as when the
command with the mode field set to Echo Buffer was issued. The
BUFFER
Buffer ID and Buffer Offset fields are ignored in this mode.
The
READ BUFFER
the drive received in the previous Echo Buffer mode
command from the same initiator. If a previous Echo Buffer mode
command did not complete successfully, the drive terminates
BUFFER
the Echo Buffer mode
status, with Sense Key set to
Code set to
COMMAND SEQUENCE ERROR
has been overwritten by another initiator, the drive terminates the
command with a
ABORTED COMMAND
OVERWRITTEN.
CHECK CONDITION
descriptor. The Offset Boundary is 3,
4 3
Offset Boundary
Buffer Capacity
command returns the same number of bytes of data as
command with a
READ BUFFER
ILLEGAL REQUEST
status, with Sense Key set to
CHECK CONDITION
and the Additional Sense Code set to
Chapter 4 SCSI Commands
READ BUFFER Command (3Ch)
READ BUFFER
status, but returns
2 1
WRITE BUFFER
CHECK CONDITION
, and the Additional Sense
. If the data in the Echo Buffer
ECHO BUFFER
0
(LSB)
WRITE
WRITE
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