Clamp-To-Black Video Switching Transition; Used As A Black Source - Honeywell MAXPRO-Net Hardware Installation Manual

7.4.3

Clamp-To-Black Video Switching Transition

When unsynchronized video sources are used in the video switching system a short
"CLAMP-TO-BLACK" period can be inserted at the video switching transition. This
allows any frame roll that may occur, to do so during the Clamp-to-Black period (i.e. the
roll is invisible), giving the illusion of synchronized video switching. The Clamp-to-Black
period is link selectable by LK2 on the RD85 module PCB. The link can be positioned in
eight positions to select a different period. The period is defined in numbers of video
fields to be clamped [i.e. link settings (fields)]:
7.4.4

Used As A Black Source

The Clamp-to-Black can be set to infinity by removing the Black Pause Link and placing
it in the Video position of LK1 (lower). In this position the module will output the Sync.
pulses only of the default camera selection. This can be used in a system as a Blank
(Black) Source. Input 1 of the subrack containing the Black Source card MUST have a
video source connected.
Rev. C
Link Position Black Period
(fields) (milliseconds)
0 zero period
1
2
4
8
16
32
64
oo (+ Audio) Continuous black
7.4-2
20Ms
40mS
80mS
160mS
320mS
640mS
1280mS
HMXMU001018
10/06