iSMA-B-AAC20 Hardware User Manual
www.ismacontrolli.com
DMP239en | 1st Issue rev. 0 | 02/2022
page 16 of 42
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5 Inputs and Outputs
The iSMA-B-AAC20 is equipped with 20 inputs and outputs:
8 universal inputs;
4 digital inputs;
6 analog outputs;
4 digital outputs.
5.1 Universal Inputs
The iSMA-B-AAC20 device is equipped with 8 universal inputs.
Universal inputs support four types of input signals:
voltage (0-10 V DC, input impedance 100
kΩ);
current (0-20 mA);
resistance and temperature measurement (10k thermistor, a full list of supported
temperature sensors is available here:
List of Supported Temperature Sensors
);
dry contact (output current 1 mA).
Current measurement is realized by voltage measurement and 200
Ω
resistance.
According to
Ohm’s
law, the current is directly proportional to the voltage, and the
resistance is the constant of proportionality. (I = U / R). According to the
Ohm’s
law
equation, for 20 mA current with 200
Ω
resistance the output voltage is 4 V. It means that
the 4 V voltage measured on the universal input corresponds to 20 mA current. The
result is expressed in millivolts.
5.1.1 Universal Input Voltage Connection
Figure 19. Universal input voltage connection
