Nevion ARC-SD-XMUX4 - Manual (Page 13)

ARC-SD-XMUX4 Rev. B
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which means that they will either control the active scaling directly (if the scaler is in Default
scaling mode) or the fallback scaling that will be chosen when no AFD/VI/WSS/SMPTE352
information is available in the automatic modes.
The GPI lines can also be made to control the output environment. By selecting from the left
part of the matrix, the output environment will be set to 4:3. Conversely, it will be set to 16:9
by selecting from the right part.
It is also possible to map one or more states to “No action”, which means that the card will
simply ignore this GPI condition. This option can be particularly useful if a subset of the GPI
values is used and the external equipment is unable to switch all four GPI lines
simultaneously. Although the GPI lines are de-bounced (filtered), unintended states could
theoretically be visited by the GPI lines in a transition from one intended value to another. It
is therefore recomm
ended to map all unused states to “No action” to get the cleanest
possible switch between scalings.
Information about the currently selected default scaling and output environment is stored in
the card (and also the system controller Multicon). If a restart occurs (from loss of power) the
latest settings will be recalled from non-volatile memory even if the GPI lines should now be
in a state that is ma
pped to ‘No action’.
Figure 3: Multicon GYDA view of the GPI to scaling map