Fc-Al Physical Interface; Physical Characteristics; Figure 10. Physical Interface; Figure 11. Port Bypass Circuit Physical Interconnect - Seagate ST118273FC Product Manual

46
9.5

FC-AL physical interface

Figure 10 shows the location of the J1 Fibre Channel single connection attachment (FC-SCA) and the J6 con-
nector. Figure 12 provides the dimensions of the FC-SCA. Figure 13 provides the dimensions of the J6 con-
nector.
Details of the physical, electrical, and logical characteristics are provided within this section. The operational
aspects of Seagate's Fibre Channel drives are provided in the Fibre Channel Interface Manual .
Figure 10. Physical interface
9.5.1

Physical characteristics

This section defines physical interface connector and its functions on a loop.
9.5.1.1 Physical description
FIbre Channel drives may be connected in a loop together or with other compatible FC-AL devices. A maxi-
mum of 127 devices may have addresses; however, one of the addresses is reserved for a fabric port switch
device. This means 126 addresses are available for FC-AL devices. More FC-AL compatible devices may
physically reside on the loop, but they will not be functional because they would not be able to obtain valid
addresses.
Port bypass circuits (PBCs) allow devices to be inserted into unpopulated locations or removed from the loop
with loop operation recovery after a brief interruption. These PBCs are located external to the FC-AL device.
Figure 11 shows the relationship between the PBC and FC-AL device.
Port Bypass
Circuit N–1
Figure 11. Port bypass circuit physical interconnect
From Previous
Drive
Drive N–1
Barracuda 18FC Product Manual, Rev. B
J6
Port Bypass
Circuit
To Next
Drive
MUX
Select
Serial Serial
In Out
Drive N
Port Bypass
Circuit N+1
Drive N+1