Datasheet

Command Processing
2-12 C141-C008
d. Disconnecting from the transfer destination device
When the transfer source device completes transfer of the frames it is
sending, it sends the CLS primitive, disconnecting from the transfer
destination device and releasing its loop use rights.
When the transfer destination device receives the CLS primitive, it resends it,
returning the CLS primitive to the transfer source device.
At this time, there is a lapse of time from the point when the frame is
received until CLS primitive is received, so the R_RDY primitive may be
sent to the transfer source device to the transfer destination device.
This R_RDY primitive is received by the transfer source device, but when the
CLS primitive is returned to the transfer source device, it is destroyed as an
invalid R_RDY primitive.
(2) Establishing Connections with the INIT and Command Execution
Even if this IDD receives a SCSI command after the power is turned on and loop
initialization is completed, that command is not executed.
In order to execute a SCSI command, it is necessary to establish logical
connections with the INIT. An example of that is shown below.
PRLI
PLOGI
FCP_CMND (inquiry)
FCP_CMND (test unit ready)
Remark. The primitives are omitted.
FCP_RSP (status = Good)
FCP_DATA (inquiry data)
FCP_RSP (Check condition + Sense Data)
PRLI ACC
IDD (Drive Side)
PLOGI ACC
INIT (Initiator Side)
Figure 2.4 Example of establishing logical connections between the INIT and IDD