Grass Valley NV8256-Plus v.1.2 - Manual (Page 15)

NV8256-Plus Digital Video Router • User’s Guide 5
2. Introduction
Switching Configurations
can be doubled to a maximum of 512 inputs and 512 outputs. Each input card and output card man-
age 16 signals each. This means that switching configurations can be based on 16, increasing in
increments of 16, up to the maximum number of inputs and outputs allowed. Each switching con-
figuration is created by installing crosspoint cards, input cards, and output cards in specific slots on
each router.
Crosspoint Card Slots and Managed Signals
The crosspoint card manages signal switching with each card managing up to 256 inputs and out-
puts. The router frame has three slots for housing crosspoint cards. (See Figure 2-2 on page 8.)
Depending on the slot in which it is installed, the crosspoint card performs different switching func-
tions. Slots are listed by location when facing the front of the router, as follows:
• Left Slot — Manages all inputs and outputs for the local router (inputs 1–256).
• Center Slot — An optional crosspoint card can be installed for redundancy as a backup for
another crosspoint card. The crosspoint card can take over active control from the crosspoint
card installed in the left slot or right slot, but not both. For more information, see
Setting
Redundant Crosspoint Card Switching on page 54.
• Right Slot — Manages all signals received through the expansion connections. The crosspoint
card receives signals from a second, connected router (inputs 257–512) and sends the signals to
local outputs 1–256.
Because the crosspoint cards installed in a specific slot manage specific outputs, depending on your
configuration, not all crosspoint cards may need to be installed. For example, if only outputs
1–256 have output cards, then a crosspoint card is only required in the left slot. The right slot can
remain empty. The middle slot is optional.
For more information on inputs and outputs and assigned numbers, see Slots and Corresponding
Signal Numbers on page 9.
Combining Input Cards and Output Cards
When connecting two routers together, different combinations of input cards and output cards can
be installed to meet switching configuration needs while minimizing cost. ‘Standard’ input cards
receive signals from the router’s local input connections and from a second, connected router
through expansion cables. ‘Filler’ input cards receive signals only from expansion cables when two
routers are connected together, but not local inputs. Because filler cards perform less signal pro-
cessing, they are less expansive then standard input cards. If a switching configuration requires two
routers, but local inputs to only one of the two routers, filler cards can be used in the router not
receiving local inputs.
Output cards manage outgoing signals. If a router is only used for receiving incoming signals, such
as in a 512 inputs and 256 outputs configuration, output cards are not needed on both routers. Out-
put cards are only required on routers distributing outgoing signals through local coaxial connec-
tors.
Examples of Switching Configurations
The following table lists possible switching configurations when two routers are connected
together. For each configuration, the table lists in which slot crosspoint cards are installed, on
which router, what type of input card is used, and if the router requires output cards. For a descrip-