Extron electronics IPCP Pro Series - Page 41

IPCP Pro Series • Hardware Features and Installation 33
• Flex I/O digital input with pull-up enabled
• When the port is configured for pull-up, switch 2 is closed, activating the
+5.0VDC pull-up resistor.
• An external short to ground creates a logic low.
• An open circuit creates a logic high
• Example application, digital input with pull-up: connecting a two-position
switch
+5.0 V
1k ohms
SW 2
SW 1
Two-position
Switch
Flex
I/O
GND
Voltage
Protection
A/D
Converter
CTL
Figure 30. Flex I/O Digital Input Application:
Two-position Switch With Pull-up
Two-position switch is open: logic high, front panel LED is off.
Two-position switch is closed: logic low, front panel LED is lit.
Digital output — To activate LEDs, control incandescent lights, or power other
devices that accept a TTL signal; or to provide contact closure control for projector lifts,
motorized screens, room or light switches via an Extron IPATRLY4 or similar device,
you can use one or more of these ports as a digital output. When a port is configured
for digital output, it offers two output states: on and off.
• When the port is set to an “on” state, (the switch 1 circuit is closed), the I/O pin is
connected to ground. Output voltage is less than 0.5volts.
• When the port is set to the “off” state (the switch 1 circuit is open), the output pin
floats (is not connected).
• If the application calls for TTL compatibility, the digital output circuit can be set up
to provide a 2kohm pull-up resistor to +5VDC, which you can use if the connected
device does not provide its own power.
• If the pull-up resistor is disabled, voltage output is determined by an external
source device.
• If the pull-up resistor is enabled, switch 2 closes, voltage output is 4.3VDC.
Each I/O port is capable of accepting 250mA, maximum.