The DRN3.1 is an interface that allows microprocessor control of a variable resistance. The DRN3.1’s isolated resistor network can be controlled by several different DDC signal types. It directly replaces a variable resistance controller and simulates the action of a slide wire or rotary potentiometer. All connections of the simulated potentiometer, the wiper and both ends of the resistance range, are available on the DRN3.1terminal strip.  The DRN3.1 accepts an ANALOG, PULSE, or FLOATING POINT input signal (including triac) and converts it into a proportional resistive output. The output resistance does not wrap around if the input signal exceeds the highest or lowest selected input value.  The DRN3.1 has on-board fail-back relays that lock out the original resistive signal during operation.  However, if the supply power is lost, control of the circuit will revert back to the original controller signal.  An easy local override can be made by placing a fixed (or variable) resistor between W and R Fail-safe terminals.  The DRN3.1 is covered by ACI's Two (2) Year Limited Warranty.