C141-E039-01EN
3 - 14
If zero is specified in the "SCSI Level" field, the IDD operates at the current SCSI level
without changing the SCSI level. However, if the correct operation mode parameter
(described later) is transferred at the same time, the IDD changes its operation mode.
The total byte length of the operation mode parameter transferred by the INIT with this
command is specified in the "Parameter List Length" field in CDB byte 8.
If zero is specified in the "Parameter List Length" field, the command is terminated normally
with only the SCSI level being changed.
When changing the operation mode, the "parameter list length" field must always be specified
by the length (=8) defined by the operation parameter, described later. If a value other than the
defined length in the "parameter byte length" field is specified, this command is terminated
with a CHECK CONDITION status (ILLEGAL REQUEST [=5] / Invalid field in CDB) and
the SCSI level and operation mode are not changed.
If the IDD's operation mode is changed by this command, a UNIT ATTENTION condition
(UNIT ATTENTION [=6] / INQUIRY Data has changed [=3F-00] is generated for all the
INITs except the INIT that issued this command.
The format for the operation mode parameter transferred by this command from the INIT to
the IDD is shown below. If the operation mode parameter is transferred in a format other than
that shown below, this command is terminated with a CHECK CONDITION status (ILLEGAL
REQUEST [=5] / Invalid field in parameter list) [=26-00] and the SCSI level and operation
mode are not changed.
Bit
Byte
7
6
5
4
3
2
1
0
0
X‘00’
1
X‘00’
2
X‘00’
3
X‘04’ (Parameter Length)
4
0
0
0
WDTR
UNTAIN
SDTR
RSRTY
0
5
0
0
0
0
0
0
RTD
6
Spindle Motor Start Delay Time
7
X‘00’ (Reserved)
The operation mode parameter is configured from a 4-byte parameter list following a 4-byte
header.
Header
Parameter
List