APV DELTA CU4 Direct connect control units are compatible with most PLC systems. The electronic module CU4 Direct Connect is connected directly by parallel wiring, i.e. every individual signal is on a separate line. The large input voltage range from 15 to 48VDC provides for versatile connections. All operating ranges within the electronic module such as the control of the solenoid valves, position feedback and LED indication are separated galvanically and can, thus, be operated with different voltages.