Grass Valley 8972PX - Manual (Page 9)

8972PX — Instruction Manual 9
8972PX HD/SD/DVB ASI
Protection Switch Module
Introduction
This manual covers installation, configuration, and operation of the 8972PX
HD/SD/DVB ASI Protection Switch module for the GeckoFlex frame.
The 8972PX module is a signal protection switch designed to maintain a
continuous Program video output. Two relay-protected input signals,
called the Primary and the Secondary, are part of a changeover switch that
continuously feeds the Program Output with a good signal. In addition, an
Alternate input signal (not relay-protected) can be enabled to provide
another backup candidate signal if desired. The module accepts HD/SD-
SDI, or DVB ASI video signals.
The switching of the input signal to maintain a continuous protected
Program Output can be manually controlled by the user with various
manual switching controls, including an external GPI interface. The
module can also be set in user configuration to switch autonomously by the
module according to the status of defined signal criteria. When switching
is controlled autonomously by the module, it will automatically switch the
Program Output to the next valid backup candidate depending on whether
the user favors to maintain the Primary input or maintain stability of the
Program Output signal.
The module can maintain the Program Output even in the event of a power
failure or when the front module is completely removed from the frame.
This is done by the presence of relay-controlled passive bypass circuitry on
the rear module that latches the relay-protected Primary or Secondary
input signal to the Relay-Protected Program Output BNC.
The 8972PX can be used in play-out and transmission applications where
switching between main and redundant paths is required. Another useful
application is for switching between alternate inputs (Please Stand By
apology slides for example) when the primary and secondary have both
failed.