Rev. B
3-2
HMXMC001013
31-Mar-06
3.3 CASCADING
In section
1.2, System structure
, the terms cascading and combining were introduced.
The next two sections explain these two concepts in detail.
Before proceeding, a detailed understanding of how the video inputs are distributed
across a subrack is essential. The following diagram (Figure 3.1), clearly illustrates this
point.
Figure 3.1: Distribution Of Video Inputs Across A Subrack
Video inputs are distributed across the entire subrack. Each video-switching module
occupies a single video output channel, or slot. Each slot can access any of the 32
video inputs contained within the switching module.
Each slot also has a cascade input. Video coming into the cascade input is only
available to the video-switching module in that video output channel. It is not distributed
across the subrack and cannot be accessed by the other video switching modules.
Having made a selection, the video-switching module then connects the desired video
input onto its video output.
The following diagram (figure 3.2) shows how two subracks are cascaded together.