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Guide to DDC

Chapter 1:Input Output (IO) Basics

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.


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


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


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 .


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

Getting Started | Chapter 1: Analog Inputs | Top | Chapter 1: Special I/Os