The AIM1 optically isolates an analog [voltage or current] input signal from its corresponding output signal. The factory calibrated output is linear and proportional [1:1 ratio] to the input signal. The AIM1 will accept a 0 to 5 VDC, 0 to 10 VDC, or 0 to 20 mA input span and output any one of those same ranges. It requires one external 24 VAC isolation transformer with floating secondary for power and has an onboard 24 VAC isolation transformer to supply the isolated output.