Fujitsu MAN3367FC Manual/User Guide - Page 32

Fujitsu MAN3367FC - Enterprise 36.7 GB Hard Drive Manual

Page 32 highlights

General Description (1) Loop configuration A port embedded with sending and receiving circuits uses differential signals to send and receive data on electric signal lines. A pair of signal lines is called a link. Since signals are sent in one direction on a link, the links in a system must be connected to form a loop. The FC-AL interface sends and receives data via nodes on the loop. Therefore, if a node connected to a loop is powered off or the interface signals of a node cannot be sent or received correctly, the loop does not work normally. A common solution preventing this problem from occurring is to add a port bypass circuit on the back plane of the system. BC in Figure 1.3 indicates the port bypass circuit. (2) Node addressing A specific device number called a SEL ID is assigned to each node on a Fibre Channel loop. The combination of signal levels on the back plane is used to define the SEL ID of a disk drive. The signal levels are sent on the seven signals (from SEL_0 to SEL_6) from CN1, which serves as an SCA interface connector. SEL_6 is the most significant bit (MSB), having a bit weight of the sixth power of 2, and SEL_0 is the least significant bit (LSB), having a bit weight of the zeroth power of 2. Any number from 0 (X'00) to 125 (X'7D') can be assigned as the SEL ID of a disk drive. 1-8 C141-E133-02EN

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148

General Description
1-8
C141-E133-02EN
(1)
Loop configuration
A port embedded with sending and receiving circuits uses differential signals to send and receive data
on electric signal lines.
A pair of signal lines is called a link.
Since signals are sent in one direction
on a link, the links in a system must be connected to form a loop.
The FC-AL interface sends and
receives data via nodes on the loop.
Therefore, if a node connected to a loop is powered off or the
interface signals of a node cannot be sent or received correctly, the loop does not work normally.
A
common solution preventing this problem from occurring is to add a port bypass circuit on the back
plane of the system.
BC in Figure 1.3 indicates the port bypass circuit.
(2)
Node addressing
A specific device number called a SEL ID is assigned to each node on a Fibre Channel loop.
The
combination of signal levels on the back plane is used to define the SEL ID of a disk drive.
The
signal levels are sent on the seven signals (from SEL_0 to SEL_6) from CN1, which serves as an
SCA interface connector.
SEL_6 is the most significant bit (MSB), having a bit weight of the sixth
power of 2, and SEL_0 is the least significant bit (LSB), having a bit weight of the zeroth power of 2.
Any number from 0 (X’00) to 125 (X’7D’) can be assigned as the SEL ID of a disk drive.