AXIS 2420 User’s Manual The Unit Connectors 65
The I/O-A Connector
Used for connecting external alarm devices and triggering images for alarm-based events,
the 4-pole I/O-A Connector provides the interface for a single di gita l in put. Connec ted to a
switch or other external security device, an image is recorded every time the switch is
activated. It also provides an auxiliary DC power input or output for the AXIS 2420.

Pinout Information

Schematic Diagram

Caution!
Pin Function
4Digital Input - Photocoupled Cathode (-) As below.
3Digital Input - Photocoupled Anode (+)
Electrically isolated from the chassis and connectors, this input can be supplied from an
external DC voltage or the DC power input/output on pin 2.
2Positive Connection for DC power input or output:
Electrically in parallel with the derived DC power for the unit, this pin can be used as an
input or output. As an input it can be used for remote applications to supply the AXIS
2420 via an external direct current source; for example, a 9-15V DC battery supply. Used
as an output, it can drive the photocoupled input or other equipment; such as a thermal
sensor. The output voltage level is dependent upon the input voltage to the unit. A
maximum current of 50mA can be sourced from the DC output.
1Common Ground
Pin 2 is connected to the derived DC power for the unit, and can be used as an external power feed for external equipment, such as an Infrared sensor. When connecting other equipment using this connector, the maximum current of 50mA must be strictly observed. Failure to do this may cause a loss of power to the unit and even damage it.
3
4
2
1

I/O-A

o
o
GND
Mode
Power
Supply
3.3V
!
!
!! !
!
!
!
!
!
o
Switch
1
!
23
o
o
o
Thermal Sensor
!
-+
Internal
PS-D9.6 VA
!
o
4
o
o
o

oo