2-97
System Startup
The timing window is positioned by setting of controls on the Sync Pulse
Generator. You are given control over the offset between the incoming reference
and the position of the autotiming window by adjustment of three rotary switches
on the front of the 064801 Sync Generator Module located in Slot A9 in the top of
the front A Bay of the switcher frame.
The range of each control on the Sync Generator is as follows for a total range of
75.8 µS:
■
COARSE: 4.74 µS (64 pixels) per step
■
MEDIUM: 296 nS (4 pixels) per step
■
FINE: 18.5 nS per step (1/4 pixel) per step
The rotary switches should be set to 6ED to place the autotiming window
approximately centered around the incoming house reference signal.
Most installations do not require any adjustment of these rotary switches because
most digital source equipment provides timed outputs that fall within the
autotiming window. If a particular source falls outside the window, it is preferable
to make adjustments at the source or through a delaying digital distribution
amplifier. However, if adjustment at the source is not possible, then the autotiming
window can be shifted until it encompasses the optimum number of available
digital inputs.
The autotiming windows shown on the timing diagrams represent the worst case
of the paths through the switcher. The actual autotiming window of most paths is
larger than shown. If an input is suspected of marginal timing, it should be
checked through one of the worst case paths. The worst case paths are outlined
below:
■
a primary source on the switched preview bus
■
a primary source on the mask bus
Symptoms of an input signal falling outside of the autotiming window are
horizontal displacement and/or odd colors, or a jittery picture that will not lock
horizontally. If you suspect an input is mistimed, and if you are certain that you
have configured the inputs correctly through the main menu panel, you can
determine roughly where its timing lies by viewing the signal at the switcher
output and temporarily changing the position of the COARSE switch until the
picture improves. This tells you which way to adjust the source equipment's
timing: Higher numbers on the rotary switch imply the source is arriving late, and
lower imply early.
Summary of Contents for Grass Valley 4000
Page 3: ...iii Tektronix Grass Valley Products P O Box 1114 Grass Valley CA 95945 916 478 3800 ...
Page 4: ...iv Tektronix Grass Valley Products P O Box 1114 Grass Valley CA 95945 916 478 3800 ...
Page 34: ...1 20 Section 1 System Overview ...
Page 138: ...2 104 Section 2 Installation ...
Page 196: ...3 58 Section 3 Functional Description ...
Page 286: ...Index 6 Index ...