Connection of passive-type analog sensors (current)

The following figure shows the connection of passive-type analog sensors (current).

1 analog input requires 1 channel

The following measuring ranges can be configured Analog Input Module AI523 Analog Input Module AI523

Current

4…20 mA

1 channel used

The function of the LEDs is described under Displays Analog Input Module AI523.

Caution

If, during initialization, an analog current sensor supplies more than 25 mA for more than 1 second into an analog input, this input is switched off by the module (input protection). In such cases, it is recommended, to protect the analog input by a 10-volt zener diode (in parallel to I+ and I-). But, in general, it is a better solution to prefer sensors with fast initialization or without current peaks higher than 25 mA.

Unused input channels can be left open-circuited, because they are of low resistance.