Grass Valley K-Frame Installation Planning Guide Jul 07 2014 - Manual (Page 43)

K-FRAME — Installation Planning Guide 43
Video Processor Frame GPI/Tally Interface
If a signal falls just outside the autotiming window, that image will be
shifted one line up or down. On SD systems a shift of one line could be
easily seen, but on higher resolution systems the lines are so narrow that a
single line shift may be difficult to observe. See the Kayenne/Karrera K-Frame
Installation & Service Manuals for K-Frame system video timing and delay
information.
Video Processor Frame GPI/Tally Interface
The GPI (General Purpose Interface) and tally interface provides a means
to transfer commands to and from the switcher to external customer pro-
vided equipment. A one wire per function parallel hardware relay mecha-
nism is used. The nominal contact rating specification for each relay is 1A,
60 V.
Note A tally interface that communicates with third party devices over Ethernet is
also available. Refer to the separate Switcher Products Protocols Manual for
specific information.
GPI and Tally Connections
Each K-Frame Video Input module has a 50 pin female subminiature D con-
nectors on the rear of the chassis, available for GPI and tally. Each connector
has 8 GPI Inputs, 24 Tally Outputs, and 8 GPI Outputs. These connectors
do not share any signals in common, other than ground reference and
chassis ground. Because of this, some GPI/Tally interconnects may require
external common connections between connectors, as explained below.
GPI Inputs
The purpose of the GPI In pins is to provide a stimulus from the customer's
equipment to the switcher. A simple connection of two pins activates the
corresponding input. An external relay contact or an open-collector output
can be employed.
CAUTION When connecting to an open-collector output, there is no ground potential
isolation between the Video Processor Frame and controlling devices.
Since the circuit ground is led out of the device, cabling should be shielded
for this kind of control. Non-shielded cables may cause EMC and/or ESD
problems. To activate a GPI In you must provide switch closure between a
particular GPI In pin and one of the two GPI In Com pins (1 and 34). Pins 1
and 34 of each connector is connected to ground (
Figure 5 ). For applications
that span across more than one connector, only one ground (common) con-
nection is required.