Grass Valley 1200 Operation Manual - Manual (Page 44)

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Section 2— Startup
GPI Menus
The GPI Inputs menu (Figure 2-15) 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 2-16). 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.
Use the (SELECT EVENT) soft knob to assign an event to the
3. 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.
When set to ON , the [GPI OUTPUT TEST] soft button in the GPI
Outputs menu cycles through the GPI outputs, closing each relay
for approximately 1/2 second, allowing you to verify GPI
operation. When finished testing, set the
button to OFF .