Grass Valley 1200 Operation Manual - Manual (Page 118)

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Section 3 — Controls & Menus
GPI Menus
The GPI Inputs menu (Figure 3-34) is displayed when you press
the
[Config] top menu button followed by the [GPI>] soft button.
From this menu, you can access the GPI inputs and also the GPI
Outputs menu (Figure 3-35). Together, these two menus allow
you to assign, view, and test the 8 GPI inputs and 8 GPI outputs.
GPI inputs are trigger signals (Closed State) that come from
external equipment via the GPI connector and start a specified
event in the switcher, such as an auto transition. GPI outputs are
triggers (Closed State) generated by switcher events that go out
via the GPI connector to external devices to cause them to take
some action.
GPI Input and Output Menu Functions:
(SELECT GPI INPUT/OUTPUT) — Highlights a GPI input or output.
(SELECT EVENT) —Assigns an event to the highlighted GPI.
[GPI OUTPUTS>] —Displays the GPI Outputs menu.
[GPI OUTPUT TEST] —When set to ON, cycles through each output,
closing its relay for approximately 1/2 second. This allows you to
check whether your GPI connections are working properly.
Two events deserve special mention:
The ALTERNATE XPT MAP selection allows you to use a GPI input to
switch between two different crosspoint maps stored in the
Crosspoint Map menu. This can be convenient when you have
two different uses for the switcher, for example, a live news show
and off-line post production.
The AUX BUS TALLY BACK selection uses the GPI as an input
condition that the switcher detects in order to tally the selected
aux bus crosspoint. This permits an external DPM to tally the aux
buses when aux bus video is on air at the DPM. Aux tally back can
be turned on and off in the Tally menu.