NV8500 family Digital Routers • User’s Guide 39
1. Introduction
Active Cards
Input Card Functions
All input cards have 9 cable equalizers. Each distributes five copies of the signal to the mother-
board. The motherboard forwards the copies to crosspoint cards for distribution to output cards, or
if an expandable frame, to expansion connectors for distribution to a connected frame. An incom-
ing signal can be distributed to any or all output cards.
Figure 1-33 shows the signal flow for an input card.
Figure 1-33. Input Card Block Diagram
Visual Indicators
All input cards have a circuit that performs status reporting and drives the card’s functions. Five
LEDs on the front of the input card indicate the card’s status: alarm (red), power good (green), soft-
ware is loaded (amber), and whether the communication with the control card is good (green) or
bad (red). For more information, see Indicator LEDs
on page 101.
Crosspoint Cards
A router frame can house up to 8 crosspoint cards and one redundant crosspoint cardset (2-card
module). The crosspoint card for the NV8144 (EM0799) and the NV8280/NV820-Plus (EM0799)
switch 144 inputs x 144 inputs. The crosspoint card for the NV8576/NV8576-Plus (EM0662) can
receive and distribute 288 inputs x 288 outputs. Both types of crosspoint cards can switch signals
with rates ranging from 19
Mb/s to 3.0 Gb/s for video signals and sample rates of 32 to 96kHz for dig-
ital audio asynchronous signals.
Crosspoint cards receive signals from the input cards (via the motherboard). The crosspoint card
then switches the signals, as directed by the control card, to the appropriate output cards (again, via
the motherboard).
The crosspoint card slot in which the crosspoint card is installed determines which of the full range
of signals are managed. For details, see Crosspoint Slots and Signals Switched
on page 13.
Redundant Crosspoints
An second crosspoint card can be installed in the NV8144 as a redundant card should the primary
crosspoint fail. Similarly, an optional, redundant crosspoint cardset can be installed in crosspoint
EM0689 (coax) SD
259M
Video rates from 19 Mb/s to 360 Mb/s.
Automatic reclocking at 270 Mb/s.
Reclocking bypassed at other rates.
EM0791 (coax)
EM0783 (coax) 3Gig, HD,
SD
259M
344M
292M
424M
Video rates from 19 Mb/s to 3 Gb/s.
Automatic reclocking at 270 Mb/s and
1.483, 1.485, 2.966, 2.970Gb/s.
Reclocking bypassed at other rates.
EM0791 (coax)
EM0693 (fiber
optic)
EM0696 (fiber
optic)
Input Card Signal Types Standard Rates Backplane
Backplane
Copies of Signal
Cable
Equalizer
Buffer
Motherboard Crosspoint
Cards
9
5
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