evertz 7703BPX-DC-RF, Руководство пользователя

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7703BPX-DC-RF
2X1 RF Protection Switch
Page 4
Revision 1.0
2.1. GPIO
A 6-pin removable terminal block labeled GPIO contains 2 GPI inputs and 2 GPO outputs
GPI’s: The two top pins on the 6 pin terminal strip are used for two General Purpose inputs (GPI).
The GPIs can be configured as active high or low by setting DIP switch 3. GPIs are active
low when DIP switch 3 is Off and GPIs are active high when DIP switch 3 is On (positioned
closest to the PCB). The GPI inputs are opto isolated with an internal pull-up resistor to +5V
or +12V as shown in Figure
2-2. See section 5.4 for information on selecting the pull-up
voltage.
GPI
GND
GPI
Command
+ 12
VDC
to
internal
circuit
220 Ohm
+ 5
VDC
LO HI
Current
Limiter
Figure 2-2 : GPI Input Circuitry
GPO: The NC, NO and COM pins on the 6 pin terminal strip are used for the General Purpose
Output (GPO). The GPO output is a set of normally open and normally closed relay
contacts as shown in Figure
2-3.
NO GPO Contact
GPO Common
from
internal
circuit
NC GPO Contact
Figure 2-3 : GPO Configuration
When connecting cables to the GPIO terminal block, a ferrite core should be
placed around the cable in order to reduce the electromagnetic interference to
limits acceptable for Class A digital devices. The ferrite impedance should be
greater than 70 ohms at 25MHz greater than 135 ohms at 100MHz