Configuring The Genlock Controls; Video Standard Selection; Genlock Source Selection; Free-Run Frequency Adjustment - evertz 7800 Manual

7800 MultiFrame Manual
7737/7837CD2 Dual Composite Decoder
5.9.

CONFIGURING THE GENLOCK CONTROLS

The Genlock menus are used to configure parameters associated with both video processing channels.
The chart below shows the items available in the Genlock menu. The following sections provide detailed
information about each of the parameters.
Video standard
Genlock source
Free-run freq

5.9.1. Video Standard Selection

Genlock
Video standard
NTSC/525
PAL-B/625

5.9.2. Genlock Source Selection

Genlock
Genlock source
Ref. 1,
Ref. 2,
Card ref,
None

5.9.3. Free-Run Frequency Adjustment

Genlock
Free-run freq
-256 to 256
0
Page - 20
Selects the module operating video standard.
Selects the input source for the reference signal.
Sets the VCXO free-running frequency.
The video standard is selected with this control.
Note: Auto mode is not available. It would cause inter-channel
standard selection arbitration issues.
The Genlock Source control allows you to select the reference video
input to the frame synchronizer. The reference must be an externally
supplied colour black. Optionally, the synchronizer can be free-run if
the "none" option is selected.
There are three possible sources of reference video; the card
reference input BNC and two frame reference inputs (Ref. 1 and Ref.
2) on the frame.
Make sure to adjust the video H and V output phase controls to
calibrate the output phase of each of the videos as described.
This control allows you to calibrate the free-running frequency of the
on-board Voltage Controlled Crystal Oscillator (VCXO). This oscillator
provides the time-base when either operating without a reference
input (free-running) or when running with a reference and the
reference video is removed.
To calibrate the free-running frequency, use this or a similar
procedure:
•
Turn off genlocking with the "Genlock source" control or
remove reference video from the reference input. Wait for the
VCXO to stabilize at its free-running frequency.
•
Apply the composite analog monitoring output video to a
scope that is externally referenced to the signal (usually plant
reference black) that you are trying to frequency match.
•
Adjust this control until the scrolling stops.
•
Turn genlocking back on or apply reference video.
Revision 1.0