Analog Outputs
An analog output is a measurable electrical signal with a defined range that is generated by a controller and sent to a controlled device, such as a variable speed drive or actuator. Changes in the analog output cause changes in the controlled device that result in changes in the controlled process.

Controller output digital to analog circuitry is typically limited to a single range of voltage or current, such that output transducers are required to provide an output signal that is compatible with controlled devices using something other than the controller's standard signal.

Common Types
There are four common types of analog outputs; voltage, current, resistance and pneumatic.

Voltage
Common output voltage ranges are 0-5 VDC, 0-10 VDC, 0-15 VDC, 1-5 VDC, 2-10 VDC and 3-15 VDC.

Current
Common output current ranges are 4-20 mA, 0-20 mA.

Resistance
Common output resistance ranges are 0-135 W , 0-270 W , 0-500 W ,
0-1000 W , 0-1500 W , 0-2 kW , 0-3 kW, 0-4 kW , 0-5 kW , 0-10 kW ,
0-20 kW , 0-30 kW , 0-40 kW .

Pneumatic
Common output pneumatic ranges are 0-20 psi and 0-15 psi.

Continue on to Chapter 1: Special I/Os