Extron Electronics VSC 500_700_700D User Guide - Manual (Page 11)

Pin RS-422 function Description
1
No connection
2 Tx- Transmit ground
3 Rx- Receive ground
4 No connection
5 Gnd Signal ground
6 No connection
7 Rx+ Receive data
8 Tx + Transmit data
9 No connection
h
Genlock input and output connectors — Connect an external blackburst signal to
the input (In) female BNC connector for genlocking the video signal in broadcast or
other sync-critical applications.
Connect any downstream equipment, which requires genlocking, to the output (Out)
female BNC connector to route the blackburst signal throughout the system in broadcast
or other sync-critical applications. See
Genlock and Vertical Interval Switching .
i
SDI (serial digital interface) connector — Connect an SDI signal to this female BNC
connector.
Genlock and Vertical Interval Switching (VSC 700 and 700D only)
For vertical interval switching (to allow clean switching between signals from several devices
during the vertical blanking period of each signal), a composite sync signal can be applied at
the Genlock In connector, and it can also be passed to another device via the Genlock Out
connector.
If the genlock connectors are used only for vertical interval switching, no horizontal or
subcarrier phase adjustments are required.
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 horizontal signal 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 results in incorrect colors or
picture artifacts.
To synchronize the video output of the VSC with a genlock signal, follow these steps:
NOTE: 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.
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.
VSC 500/700/700D User Guide • Installation and Operation 5