EVD4 is an evolved PID controller complete with driver for stepper motors specially designed for the management of electronic expansion valves in refrigerant circuits. It features sophisticated control functions 

and can be used in many operating configurations in refrigeration and air-conditioning systems, such as:

- PID control of superheat with protection and safety compensation functions;

- PID control on one measurement (pressure or temperature);

- positioner for electronic expansion valves controlled by 4 to 20 mA or 0 to 10 Volt signal. 

The device is configured and the address set via serial interface and the user interface software is stored in non-volatile memory.