Abstract: The invention relates to a control valve for adjusting a process fluid flow of a process plant, comprising a valve housing (8) with a valve seat (14) and a valve member (16) connected to a valve rod (18), which cooperates with the valve seat (14) for opening and closing the control valve (2), wherein the valve rod (18) is electrically connected to the valve housing (8) through a contact device (42, 43, 45). The invention is characterized in that a measuring device (26) for the ohmic transition resistance measurement of the contact device (42, 43, 45) is provided, and that the measuring device (26) is arranged in a measuring line (24) that connects the valve housing (8) to the valve rod (18).

Abstract: An electro-pneumatic actuator, such as a positioner or an I/P transducer array, for a field device of a processing plant, such as a brewery, a petrochemical plant or the like, can include a pneumatically operated display configured to visually and/or acoustically display at least one field device-specific operating information. The information can include a drive or valve position, or a regulating variable. The electro-pneumatic actuator can be configured to output at least one pneumatic drive actuating signal to a pneumatic drive so as to set a final controlling device, such as a control valve, of the field device. The electro-pneumatic actuator can be configured to output at least one pneumatic display actuating signal to the pneumatically operated display, which can differ from the pneumatic drive actuating signal.

Abstract: The invention relates to a control valve for adjusting a process fluid flow of a process plant, comprising a valve housing (8) with a valve seat (14) and a valve member (16) connected to a valve rod (18), which cooperates with the valve seat (14) for opening and closing the control valve (2), wherein the valve rod (18) is electrically connected to the valve housing (8) through a contact device (42,43, 45). The invention is characterized in that a measuring device (26) for the ohmic transition resistance measurement of the contact device (42, 43, 45) is provided, and that the measuring device (26) is arranged in a measuring line (24) that connects the valve housing (8) to the valve rod (18).

Abstract: An electro-pneumatic actuator, such as a positioner or an I/P transducer array, for a field device of a processing plant, such as a brewery, a petrochemical plant or the like, can include a pneumatically operated display configured to visually and/or acoustically display at least one field device-specific operating information. The information can include a drive or valve position, or a regulating variable. The electro-pneumatic actuator can be configured to output at least one pneumatic drive actuating signal to a pneumatic drive so as to set a final controlling device, such as a control valve, of the field device. The electro-pneumatic actuator can be configured to output at least one pneumatic display actuating signal to the pneumatically operated display, which can differ from the pneumatic drive actuating signal.

Abstract: In a method or device for powering a field device for a processing plant, the field device is driven by a process signal of an electrical power supply so that an electronic unit connected to the power supply outputs a process control signal. A required power level of the electronic unit is determined for outputting the control signal. A portion of an electrical power of the power supply exceeding the required power level is stored.

Abstract: In a method for communicating electrical positioning information of an actuator-positioned final control element such as a valve element, the positioning information resulting from continually sensing the position of the final control element, a binary signal is formed or received signalling a condition 0 (zero) when the final control element has attained a predefined position and a condition 1 (one) when the final control element has not attained the predefined position or the predefined position range. For forming a positioning signal, the corresponding signal condition of the binary signal and the associated continually sensed positioning information are combined such that the corresponding signal condition of the binary signal or the positioning information or both can be optionally invoked from the positioning signal.

Abstract: In a method for communicating electrical positioning information of an actuator-positioned final control element such as a valve element, the positioning information resulting from continually sensing the position of the final control element, a binary signal is formed or received signalling a condition 0 (zero) when the final control element has attained a predefined position and a condition 1 (one) when the final control element has not attained the predefined position or the predefined position range. For forming a positioning signal, the corresponding signal condition of the binary signal and the associated continually sensed positioning information are combined such that the corresponding signal condition of the binary signal or the positioning information or both can be optionally invoked from the positioning signal.

Abstract: In a method or device for powering a field device for a processing plant, the field device is driven by an electrical power supply so that the field device outputs a process signal. A required power level of the electronic circuit is determined for outputting the process signal. A portion of an electrical power of the power supply exceeding the required power level is stored.

Abstract: A positioner for a fluid actuator comprising an electronics assembly designed for setpoint/actual value comparison and for outputting a feedback control signal includes a current/pressure transducer receiving the feedback control signal for controlling the actuator, an analog power supply, particularly in a range 4 to 20 mA, for powering the electronics assembly, and an additional voltage input, particularly in a range of up to 24 V, wherein said voltage input is configured as a further power supply for powering the current/pressure transducer separate from the analog power supply.

Abstract: A positioner for a fluid actuator comprising an electronics assembly designed for setpoint/actual value comparison and for outputting a feedback control signal includes a current/pressure transducer receiving the feedback control signal for controlling the actuator, an analog power supply, particularly in a range 4 to 20 mA, for powering the electronics assembly, and an additional voltage input, particularly in a range of up to 24 V, wherein said voltage input is configured as a further power supply for powering the current/pressure transducer separate from the analog power supply.

Abstract: A functional test apparatus for a field device, particularly for a quick-acting gate valve for an emergency system, preferably of a chemical installation, of a gas burner or the like, with the field device configured to change or to be changed to a specific operating mode, particularly a safety or emergency operating mode, in case there is no power supply, comprises at least one device for detection of operating data for the field device, and at least one non-volatile memory for saving the detected operating data, at least one electrical energy buffer is provided which acts on the device for detention of operating data and on the non-volatile memory for supplying them with power, such that the operating data of the field device is detected and is saved in a non-volatile manner at least while the field device is making a transition to the specific operating mode.

Abstract: An input circuit for a field device for communication with bidirectional signals superposed on an analog signal, the input circuit being part of a current loop, supplies the field device with energy and simultaneously carries an analog current signal for prescribing a reference value. The field device is connected to an actuator that is suitable for achieving the reference value, and the input circuit has a voltage limiter, a shunt resistor and an inductance connected in series between its input and output. The input signal of an analog-to-digital converter can be taken at the shunt resistor. The voltage limiter is connected in parallel with a voltage regulator. The inductance is coupled via a capacitance to a reception unit and/or to a transmission unit for digital signals.