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7.Electrical Interface
© 2023 China Daheng Group, Inc. Beijing Image Vision Technology Branch 83
3.3V
Line0+
Line0/1-
INPUT0
External Circuit
5V-24V
1
6
2
5
3
4
Figure 7-2 Opto-isolated input circuit (ME2S)
Logic 0 input voltage: 0V~+2.5V (Line0+ voltage)
Logic 1 input voltage: +5V~+24V (Line0+ voltage)
Minimum input current: 7mA
The status is unstable when input voltage is between 2.5V and 5V, which should be avoided
When the external input voltage is 5V, there is no need for circuit-limiting resistance in the external
input. But if there is a series resistance, please ensure the value is less than 90Ω. In order to protect
the Line0+ while the external input voltage is higher than 9V, a circuit-limiting resistance is needed in
the external input. The recommended values are shown in Table 7-6
External input voltage
Circuit-limiting resistance (Rlimit)
Line0+ input voltage
5V
Non or <90Ω
About 5V
9V
680Ω
About 5.5V
12V
1kΩ
About 6V
24V
2kΩ
About 10V
Table 7-6 Circuit-limiting resistor value
The connection method of the opto-isolated input circuit and the NPN and PNP photosensor is shown
below. The relationship between the pull-up resistor and the external power supply voltage is shown in
Table 7-6.
8
5
1
4
3
7
2
6
3.3V
Line0+
Line0-
INPUT0
External circuit
Camera internal circuit
Signal
output
Power +
PWR
GND
NPN
Pull-up
resistor
Figure 7-3 NPN photosensor connected to opto-isolated input circuit (MER2/ME2P/ME2L)