Grass Valley 1200 Installation - Manual (Page 58)

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Section 2 Ñ Installation
GPI Menus
The GPI Inputs menu (Figure 2-22) is displayed when you press the
[CONFIG] top menu button followed by the [GPI>] soft button. From this
menu, you can view the GPI Inputs or access the GPI Outputs menu
(Figure 2-23). Together, these two menus allow you to assign, view, and
test the 8 GPI inputs and 8 GPI outputs.
GPI inputs are trigger signals that come from external equipment (via the
GPI connector at the back of the frame) and start a specified event in the
switcher, such as an auto transition. GPI outputs are trigger signals
generated by switcher events that go out via the GPI connector to external
devices to cause them to take some action. You can assign events to the GPI
Inputs or Outputs as follows:
1. Display the GPI Input or Output menu.
2. Change the event assigned to a GPI using the (SELECT GPI INPUT/OUTPUT)
soft knob to highlight the desired input or output.
3. Use the (SELECT EVENT) soft knob to assign an event to the highlighted
GPI.
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 Input 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 tallyback can be turned on
and off in the Tally menu.
The [TEST] soft button in the GPI Outputs menu, 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.
When finished testing, set the
[TEST] button to OFF .