Rev. B
3-6
HMXMC001013
31-Mar-06
3.4 COMBINING
To maintain a high quality of video signal, larger configurations are constructed using
‘Combining’.
Figure 3.5: Combining
By using the method of combining, a video system can have a maximum of 1280 video
inputs with 256 output channels in a single full matrix. When selecting any input, the
video signal only passes through two video switching subracks.
•
Pre-selection subrack
•
Combiner subrack.
3.4.1 Pre-selection
subracks
The pre-selection subracks used in combining, are normal video switching subracks.
They are identical to the ones used in the previous cascading example, with video inputs
distributed across the entire subrack.
3.4.2 Combiner
subracks
Combiner subracks are different from the pre-selection subracks because video inputs
to the combiner subrack are not distributed across the entire subrack.
Each slot of a combiner subrack (video output channel) has its own independent video
inputs (A T). These video inputs are
only
available for connection to that video
output.