POSITION CONTROLLER FOR A PNEUMATIC FIELD DEVICE

摘要

The position controller for a pneumatic field device comprises a current-pressure transducer system having at least two I/P-transducers creating separate pneumatic control signals. Microelectronics creates at least two electrical control signals for the I/P-transducers. A pneumatic signal switching valve has at least two pneumatic inputs for the at least two pneumatic control signals, a pneumatic output for transferring a pneumatic control signal to a working chamber of the pneumatic field device and an electrical switch signal input. The pneumatic signal switch valve comprises a first switch position which blocks a first of the at least two pneumatic control signals and a second switch position which blocks a second of the pneumatic control signals.

主权项

1. A position controller for a pneumatic field device of a process plant, comprising:
a current-pressure transducer system having at least two I/P-transducers creating at least two separate pneumatic control signals; microelectronics creating at least two electrical control signals for the at least two I/P-transducers; a pneumatic signal switch valve having at least two pneumatic inputs for the at least two pneumatic control signals, a pneumatic output for transferring a pneumatic control signal to a working chamber of the pneumatic field device, and an electrical switch signal input; and the pneumatic signal switch valve comprising a first switch position in which it blocks a first of the at least two pneumatic control signals and a second switch position in which it blocks a second of the at least two pneumatic control signals.