Grass Valley Kayenne Installation Planning Guide Aug 30 2011 - Manual (Page 62)

62 KAYENNE — Installation Planning Guide
Section 4 — System Cabling
GPI and Tally Connections
The Kayenne 4-RU Video Processor Frame has two 50 pin female submin-
iature D connectors on the rear of the chassis, available for GPI and tally.
The 8-RU Frame has four connectors. Each connector is activated by the
presence of an ME module installed in the frame, providing up to four con-
nectors on a four M/E system.
Each 50 pin connector has 8 GPI Inputs, 24 Tally Outputs, and 8 GPI Out-
puts. These four 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 connec-
tors, 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 59 ). For applica-
tions that span across more than one connector, only one ground (common)
connection is required.