Cheetah 64NEX Digital Video Router
Publication 81-9059-0685-0, Rev. A
March 2011
Proprietary Information of PESA
6-6
6.4
F
UNCTIONAL
D
ESCRIPTION
-
D
IGITAL
V
IDEO
M
ATRIX
C
ARD
Refer to Figure 6-5 as we discuss the various circuit functions of this card. There are 64 identical input
channel paths provided. Video signals are derived from the output channels of the input buffer cards and
routed to the inputs of the matrix card. As a signal enters the card it is routed to an Input Buffer stage,
internal to the crosspoint device. This device contains the switching circuitry to deliver a signal on any of
its input channels to any of its output channels. Switching data for the crosspoint device is received from
the on-board microcontroller circuitry. The crosspoint also contains output buffer stages, internal to the
device, for isolation. Video from each device channel is available at the card edge connector where it is
routed to the output combiner cards.
The On-Board Microcontroller is the interface between the matrix card and the frame control system. The
microcontroller constantly monitors the status and health of the card and reports this data to the system
frame controller. Commands from the frame controller are interpreted by the microcontroller circuitry and
select the active inputs and outputs of the crosspoint device. Data indicating the status of the operating
voltage rails is sent to the microcontroller by circuitry contained in the Voltage Regulator stage. The
microcontroller also provides a visual indication of certain board functions by controlling the operating
state of the status LEDs. Operating voltages necessary to power the matrix card circuitry are derived from
on-board voltage regulator devices.
F
IGURE
6-5
B
LOCK
D
IAGRAM
–
D
IGITAL
V
IDEO
M
ATRIX
C
ARD
Crosspoint
Matrix Array
With Internal
Buffer Stages
Output 1
Signal Inputs
From Input
Buffer CCAs
Input 1
Input 64
Output 64
Voltage Regulation
And
Distribution
Power For All
Circuit Elements
On-Board
Microcontroller
Visual Status
LEDs
28 VDC From
Power Supply
Module
System Control
Interface
Signal Outputs
To Output
Combiner CCAs
Summary of Contents for 64NEX
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