Tektronix Grass Valley 4000, Installation And Service, Page: 130 / 286

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Section 2 — Installation
System Configuration
Follow the Software Setup procedures described in the Startup section of your
User’s Guide (TP0790) to configure the 4000 system to your installation. In
addition to assigning sources, the process includes setting configuring inputs,
output levels, external interfaces, and system parameters. These menu items are
accessed through the Configuration menu on the Control Panel Main Menu
Subpanel.
System Timing
The Model 4000 switcher has timing compensation to allow the autotiming range,
or “window”, of the switcher digital inputs to be positioned in relation to an
analog reference signal. This reference is a “house” analog timing signal such as
color black (refer to The Analog Reference Connection heading on
page 2-67 ).
Analog inputs should be timed to the reference signal using external timing
equipment.
Autotiming
The Model 4000 Series uses autotiming, a system of synchronization which
automatically times all digital inputs. The signal processing in the system is a
stream of digital data which includes horizontal and vertical blanking intervals to
properly synchronize and format the picture when viewed, transmitted, or
recorded. Within the blanking intervals are data words that identify the start of
active video (SAV) and the end of active video (EAV). The Model 4000 circuitry
uses these data words as feedback to automatically time all digital inputs together.
Detailed timing diagrams have been included to help you see the possible
positions of the timing windows in relation to the analog reference. As shown in
the timing diagrams, the range for error correction is approximately 44 µS for the
Model 4000-2 and 26 µS for the
Model 4000-3. Refer to the following figures during this procedure:
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Figure 2-56 illustrates the timing for the Model 4000-2A/B switcher
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Figure 2-57 illustrates the timing for the Model 4000-3 switcher