3-7
VSC 200/200D/300/300D Operation
If the genlock connectors are used only for vertical interval switching, no horizontal
or subcarrier phase adjustments are required, and the genlock LED does not light.
Genlock setup
Genlock differs from simple vertical interval switching in that an external device (a
black burst generator) generates a reference sync signal for the system, and every
device that uses that signal has its output signal’s horizontal and subcarrier phases
adjusted to exactly match that of the generator to allow precise timing and full
synchronization. Genlocked systems produce cleaner switches between inputs
than do those without this type of synchronization.
An oscilloscope is required for genlock setup, and a vectorscope is recommended.
Waveform monitors of types other than a vectorscope may give the appearance that
timing is adjusted correctly when it is 180 degrees out of phase, which will result in
incorrect colors or picture artifacts.
All equipment in the system must be powered up and turned on for at least 15
to 20 minutes before genlock setup adjustments can be made and before the
equipment is used in a genlocked application.
To synchronize the scan converter’s video output with a genlock signal, follow
these steps:
1.
Power up and turn on all the devices that will use the genlock signal. The
devices must be on for at least 15 to 20 minutes before proceeding with any
adjustments.
2.
Connect the active timing source signal to the Genlock In connector on the
rear panel (figure 21).
Figure 21 — Cable connections for genlock setup
3.
Connect the active computer video input signal to the appropriate input as
explained in step 2 of the cabling section on page 2-6. Ensure that the input is
properly terminated either by connecting a local monitor to the other input/
loopout (loop through) connector, or by setting the 75 ohm/Hi Z switch to
75
Ω
. The Genlock LED lights to indicate that the scan converter is receiving
an acceptable genlock (black burst) sync signal via the Genlock In connector.
4.
Connect oscilloscope (“scope”) probe A to the Genlock Out connector. This
will provide the scope’s reference signal. In order to avoid altering the
genlock signal, use the cabling configuration that will be used in the
installation. Either connect the genlock signal cable from the scope to the next
device in the system to be timed, or provide 75 ohm termination at the scope’s
genlock output.
5.
Connect scope probe B to the scan converter’s composite video output
connector. Ensure that the
standard
screen of the
configuration controls
menu is
set to the desired standard (NTSC or PAL; see page 3-3).
50/60 Hz 0.5A
100-240
INPUT/LOOP OUT
G
E
N
L
O
C
K
VIDEO
S-VIDEO
R/R-Y
G/Y
B/B-Y
H/HV
V
OUT
H
HV
SOG
DIGITAL
OUT
IN
VGA
MAC
To Scope Probe A
and Termination
To Scope Probe B
Computer Video
Signal In
Timing Source
OUT
RS-232
REMOTE
im Vertrieb von
CAMBOARD Electronics
www.camboard.de
Tel. 07131 911201
Fax 07131 911203
