Fujitsu MAA3182FC Series, Руководство пользователя

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C141-E054-02EN 1 - 3
1.1.1 Node/Port
Any device connected to Fibre Channel topology is called “node”.
In the application of this drive, the drive itself and the initiator are the nodes.
Each node has at least one port to connect other nodes and the port is called N_port.
Especially, in FC-AL, the port is called “NL_Port” where “NL” stands for node loop.
The drive provides two ports and each port is connected to each FC-AL.
See Figure 1.1.
1.1.2 Link
Each port provides both Receiver and Transmitter.
The drive uses electrical wires (differential signal) to receive or transmit the information.
This pair of wires is called a “link”.
See Figure 1.1.
1.1.3 Arbitrated Loop
Arbitrated loops are defined as “private loop” or “public loop”.
Private loop has no FL_port (for fabric loop) and all nodes are NL_ports.
If there is a FL_port which is managing the loop, the loop is called a public.
This can connect up to 126 active NL_port and one FL_port to the same loop.
And the NL_ports use arbitration to establish a Initiator-Target connections.
See Figure 1.1.
1.1.4 Port Bypass Circuit (BC)
Port bypass circuit is to bypass the drive if it cannot provide loop services.
For example, by removing the drive, unable to obtain valid data, or by any special condition.
The port bypass circuit is located external to the drive. (for example, on the back plane)
Figure 1.2 shows the relationship between the drive and the circuit.
Output
Input
Select
M
U
X
AL-4/FC
drive
Port_A
Port_B
②
①
BC
Note
Select function is performed by “-EN port bypass A” and “-EN port bypass B”.
Figure 1.2 Port Bypass Circuit
①
Regular route (Bypass circuit off)
②
Via bypass (Bypass circuit
on)
From previous port
To next port