Solenoid Industrial Valve Stroke Test

Safety circuits in continuous operation process plants typically contain solenoid valves and industrial valves that remain in an end position during normal operation. Valve function must be tested in conformance with IEC 61508 and IEC 61511 regulations. Partial valve stroke tests help confirm valve function, availability, and uncover any malfunctioning industrial valves.

HART communication can transmit the valve stroke test data as long as the system is in operational mode, or is equipped with separate wiring between the control system and the solenoid valves. The new solenoid driver KFD2-RCI-Ex1 allows communication with the valve via the very same two-wire connection, even when the system is off.

The switching signal is transferred into a supply current, while communication with the field device takes place via a second parallel HART transparent input that is independent from valve position. If the control system turns off the valve, the HART switching function of the KFD2-RCI-Ex1 solenoid driver delivers a small current in order to maintain communication - even without valve activation! All diagnosis information is available at any time via the same wiring pair, while fully conforming to SIL3 requirements.