Miranda NV8144 Скачать руководство пользователя

Страница: 26 / 140

Rev 2.2 • 27 Mar 10

1. Introduction

Signal Rates and Flow

tors on the backplane associated with the input card are assigned signal numbers 1–9. For more
details on router card slots and the range of signal numbers assigned each slot, see

Slots and Corre-

sponding Signal Numbers

on page 8.

Important:

Although card slots are numbered from left-to-right in ascending order when facing

the front of the router frame, physical signal connections are made to backplane connectors located
on the

rear

of the frame. This means that when facing the rear of the router the slots are numbered

the

opposite

, or right-to-left. To put it another way, when you are facing the rear of the frame, the

card slots, and resulting range of signal numbers associated with each slot, are in

reverse order

For

example, when viewing the router frame from the rear Input Slot 1 (signals 1–9) corresponds with
the backplane installed in the farthest

right

location. Input Slot 2 is the next slot to the

left

of Slot 1,

Input Slot 3 is the next slot to the

left

of Slot 2, and so on.

Figure 1-11 illustrates how connectors are associated with signal numbers when facing the

rear

the router frame. In this example, each number represents a signal number assigned to an individual
connector on a backplane receiving inputs. Each column corresponds to the range of signal num-
bers managed by the card in that slot. In this example, there are a total of 16 input card slots. Notice
that signals are numbered in ascending order from top-to-bottom and right-to-left.

Figure 1-11. Example of backplane connectors and corresponding signal numbers

NV8576 and NV8576-Plus Note

All connectors and corresponding signals are numbered from top-to-bottom. This includes the
NV8576 and NV857-Plus frame, which have two separate regions for backplanes: one in the upper
half of the frame and one in the lower half of the frame. Backplanes installed in the lower portion of
the frame are rotated 180° from those in the upper portion and “face” in the opposite direction. (See

Backplanes

on page 29.) Even though the backplanes are installed differently in the upper and

lower regions, the signal numbering for each backplane connector

is identical

. In other words,

whether the backplane is installed in the upper region or lower region, when facing the rear of the
router frame the signal numbers applied to connectors are always numbered in ascending order
from top-to-bottom and right-to-left.

LC input backplanes and LC expansion backplanes have five sets of two connectors each for a total
of 10 connections. Because only 9 input signals are managed by an input card and only 9 output
signals are managed by an expansion card, one connector is left unused. For the NV8576 and the
NV8576-Plus, in the upper region of the frame the bottom connector is not used. In the bottom

Note

For an enumeration of the NV8576 and NV8576-Plus I/O connectors and corre-
sponding signal number, see

NV8576 I/O Signal Numbering

on page 119.

136 127 118 109 100 91 82 73 64 55 46 37 28 19 10 1
137 128 119 110 101 92 83 74 65 56 47 38 29 20 11 2

138 129 120 111 102 93 84 75 66 57 48 39 30 21 12 3

139 130 121 112 103 94 85 76 67 58 49 40 31 22 13 4

140 131 122 113 104 95 86 77 68 59 50 41 32 23 14 5

141 132 123 114 105 96 87 78 69 60 51 42 33 24 15 6

Input Slots

Lowest signal

number is at the