TESTEINRICHTUNG FÜR NOTABSCHALTUNG

摘要

An emergency shutdown system for a process control system includes an emergency shutdown (ESD) valve and an associated valve actuator. An emergency shutdown (ESD) controller provides output signals to the ESD valve in the event of a failure in the process control system. A solenoid valve responds to the ESD controller to vent the actuator to a fail state. A digital valve controller (DVC) test strokes the ESD valve. An impedance booster device enables the dc powering of the solenoid valve and the DVC over a two wire line while still permitting digital communication over the same two wire line.