2.
Electrical Interface
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 8
2.2.1. Line2/Line3 (bidirectional) Circuit
Line2 can be configured as input or output through the software interface. Line3 is the same. The internal
equivalent circuit of the camera is illustrated as follow.
3.3V
Line2
Line3
INPUT2
INPUT3
OUTPUT2
OUTPUT3
PTC
PTC
GND
Figure 2-2 GPIO2/3 (bidirectional) circuit
2.2.2. Line2/3 configured as input
Logic 0 input voltage: 0V~+0.6V (Line2/3).
Logic 1 input voltage: +1.9V~+24V (Line2/3).
The status is unstable when input voltage is between 0.6V and 1.9V, which should be avoided.
When input of Line2/3 is high, input current is lower than 100uA; when input of Line2/3 is low , input
current is lower than -1mA.
When Line2/3 is configured as input, if the corresponding output device is common-anode connected,
pull-down resistor over 1K should not be used, otherwise the input voltage of Line2/3 will be over 0.6V
and logic 0 cannot be recognized stably
When Line2/3 is configured as input, the equivalent circuit of camera is shown as Figure 2-3, for Line2
as an example.
Input signal rising delay: <2μs (0°C~45°C)
, parameter description as shown in Figure 2-4.
Input signal falling delay: <2μs (0°C~45°C)
, parameter description as shown in Figure 2-4.
