Controlling The Reader 'Look Ahead' Compensation - evertz 5950-SID Instruction Manual

DISPLAY
PROCESSED
DIRECT
OPERATING INSTRUCTIONS
Model 5950-SID VITC Reader / Source ID Decoder Manual

3.5.4. Controlling the Reader 'Look Ahead' Compensation

The DISPLAY menu item is used to select whether the normal 'lookahead'
compensation for reader dropouts is active or not. Normally, the data is
read in one frame and displayed with an 'add 1 frame' compensation. This
method guarantees an 'on time' character display for LTC and also helps to
cover any minor reader disturbances. In some operational modes it is
desirable to disable this feature and to display exactly what is being read.
When reading VITC, it is possible to read and display the information in the
same video field, thus maintaining field accuracy even in DIRECT mode.
The topmost positions of the character generator are not available when in
the direct mode.
Select PROCESSED to enable normal 'lookahead' compensation.
Displays from either the LTC or VITC readers will be 'on time' but will not
follow code discontinuities immediately.
Select DIRECT to enable DIRECT display mode. Data is displayed exactly
as it is read without 'lookahead' compensation. Displays from the VITC
reader will be 'on time' but cannot be positioned at the very top of the
raster. Displays from the LTC reader will be behind by two frames.
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