General Purpose Inputs And Outputs; Figure 2-2: Gpi Input Circuitry; Figure 2-3: Gpo Output Circuitry - evertz 7700 Manual

2.3.2. General Purpose Inputs and Outputs

Three pins on the 9 pin D connector are used for three general purpose inputs (GPIs). One of these inputs
is used for a 6 Hz input to the downconverter. The GPI1 and GPI2 inputs are used to select user presets
1 and 2 respectively. The GPIs are active low with an internal pull up (3.6k ohm) resistor to +5V or +12V.
The user can activate GPIs simply by connecting the GPI input pins to Ground. This can be done with a
button, switch, relay or an open collector transistor. See section 7.4 for information on selecting the pull-up
voltage. Figure 2-2 shows the input circuit for the general purpose inputs.
The GPO is active low with internal pull up (10k Ohm) resistors to +5V. When the output goes low it is able
to sink up to 10mA. When high, the signal will go high (+5V). Do not draw more than 100µA from the
output. Figure 2-3 shows the circuit for the general purpose output. The GPO output is not used at this
time.
+ 5
VDC
GPI
GPI
Command
GND

Figure 2-2: GPI Input Circuitry

From Internal
Circuit

Figure 2-3: GPO Output Circuitry

Revision 1.1
7711HDC HD Broadcast Quality Down Converter
J80
+ 12
VDC
3.6 K
internal
+ 5 Volts
10 K
10 ohm
GPO
GND
7700 MultiFrame Manual
to
circuit
7711HDC - 5