Abstract: A two-wire process variable transmitter for use in an industrial process, including a process variable sensor configured to sense a process variable of a fluid of the industrial process. Output circuitry is configured to provide an output on a two-wire process control loop which is related to the sensed process variable. Loop current measurement circuitry measures a loop current flowing through the two-wire process control loop and terminal voltage measurement circuitry measures a voltage related to a terminal voltage of the process variable transmitter. The terminal voltage can be a voltage measured across an electrical connection of the two-wire process variable transmitter to the two-wire process control loop. Input circuitry is configured to receive a diagnostic command from the two-wire process control loop.

Abstract: An adapter for coupling to a process control transmitter of the type used to monitor a process variable in an industrial process includes a first connection configured to couple to a first side of a two wire process control loop, a second connection configured to couple to a second side of the two wire process control loop and in series with a first connection to a process control transmitter, and a third connection configured to couple to a second connection of the process control transmitter. Wireless communication circuitry is coupled to at least the third connection and is configured to provide wireless communication for the process control transmitter. Intrinsic safety circuitry coupled to at least one of the first, second and third connections is configured to limit transfer of electrical energy to a value which is less than an intrinsic safety value.

Abstract: A process device wireless adapter includes a wireless communications module, a metallic housing, and an antenna. The wireless communications module is configured to communicatively couple to a process device and to a wireless receiver. The metallic housing surrounds the wireless communication module and has a first end and a second end. The first end is configured to attach to the process device. In one embodiment, a metallic shield contacts the housing second end such that the metallic shield and the housing form a substantially continuous conductive surface. The antenna is communicatively coupled to the wireless communication module and separated from the wireless communication module by the metallic shield. Preferably, the wireless communications module illustratively includes a printed circuit board that has a length that is greater than its width.

Abstract: An adapter for coupling to a process control transmitter of the type used to monitor a process variable in an industrial process is provided. The adapter includes I/O circuitry configured to couple to a two wire process control loop and to the process control transmitter and communicate on the process control loop. Wireless communication circuitry couples to the two wire process control loop and is configured to transmit an RF signal. Power supply circuitry provides power to the wireless communication circuitry.

Abstract: A wireless adapter for use with a two-wire process control loop is configured to couple to a process field device in an industrial process control system. The wireless adapter is coupled to the two-wire process control loop and provides wireless communication to the process field device. The adapter includes first and second loop terminals configured to couple in series with the two-wire process control loop. Wireless communication circuitry is coupled to the first and second loop terminals and is adapted to provide wireless communication to the process field device. Loop current bypass circuitry is electrically connected between the first and second loop terminals and is configured to provide a loop current path therebetween in response to an open circuit in wireless communication circuitry.

Abstract: A field device for use in an industrial process control or monitoring system includes terminals configured to connect to a two-wire process control loop. The loop carries data and provides power to the field device. RF circuitry in the field device is provided for radio frequency communication. A power supply powers the RF circuitry using power received from the two-wire process control loop.

Abstract: A two-wire process variable transmitter for use in an industrial process, including a process variable sensor configured to sense a process variable of a fluid of the industrial process. Output circuitry is configured to provide an output on a two-wire process control loop which is related to the sensed process variable. Loop current measurement circuitry measures a loop current flowing through the two-wire process control loop and terminal voltage measurement circuitry measures a voltage related to a terminal voltage of the process variable transmitter. The terminal voltage can be a voltage measured across an electrical connection of the two-wire process variable transmitter to the two-wire process control loop. Input circuitry is configured to receive a diagnostic command from the two-wire process control loop.

Abstract: A field device system for use in an industrial process includes a field device configured to couple to the industrial process and monitor or control the industrial process. The field device provides a temperature control signal output related to a temperature of the field device. A heater coupled to the field device heats the field device in response to the temperature control signal.

Abstract: A wireless adapter for use with a two-wire process control loop is configured to couple to a process field device in an industrial process control system. The wireless adapter is coupled to the two-wire process control loop and provides wireless communication to the process field device. The adapter includes first and second loop terminals configured to couple in series with the two-wire process control loop. Wireless communication circuitry is coupled to the first and second loop terminals and is adapted to provide wireless communication to the process field device. Loop current bypass circuitry is electrically connected between the first and second loop terminals and is configured to provide a loop current path therebetween in response to an open circuit in wireless communication circuitry.

Abstract: A process device wireless adapter includes a wireless communications module, a metallic housing, and an antenna. The wireless communications module is configured to communicatively couple to a process device and to a wireless receiver. The metallic housing surrounds the wireless communication module and has a first end and a second end. The first end is configured to attach to the process device. In one embodiment, a metallic shield contacts the housing second end such that the metallic shield and the housing form a substantially continuous conductive surface. The antenna is communicatively coupled to the wireless communication module and separated from the wireless communication module by the metallic shield. Preferably, the wireless communications module illustratively includes a printed circuit board that has a length that is greater than its width.

Abstract: An adapter for coupling to a process control transmitter of the type used to monitor a process variable in an industrial process includes a first connection configured to couple to a first side of a two wire process control loop, a second connection configured to couple to a second side of the two wire process control loop and in series with a first connection to a process control transmitter, and a third connection configured to couple to a second connection of the process control transmitter. Wireless communication circuitry is coupled to at least the third connection and is configured to provide wireless communication for the process control transmitter. Intrinsic safety circuitry coupled to at least one of the first, second and third connections is configured to limit transfer of electrical energy to a value which is less than an intrinsic safety value.

Abstract: A field device for use in an industrial process control or monitoring system includes terminals configured to connect to a two-wire process control loop. The loop carries data and provides power to the field device. RF circuitry in the field device is provided for radio frequency communication. A power supply powers the RF circuitry using power received from the two-wire process control loop.

Abstract: A process transmitter suitable for coupling to a process loop. The process transmitter includes a power regulator adapted to receive a power signal on the process loop and to provide a first signal having a first voltage. Digital components of the process transmitter are electrically coupled to the power regulator to receive power from the first signal. A step-up converter is electrically coupled to the power regulator and receives the first signal. The step-up converter outputs a second signal having a second voltage larger than the first voltage. Analog components of the process transmitter are electrically coupled to the step-up converter to receive power from the second signal.

Abstract: An industrial process control system includes a remote transmitter that measures a process variable to transmit data over a process control loop. A local databus interface includes an active current source and is configured to transmit and/or receive data on a local databus. The local databus includes a signaling wire operated to a high signal level during idle communications and modulated between the high and a low signal level during data communication. The active current source is coupled to the signaling wire of the databus to limit current drawn by the signaling wire during a low signal level.

Abstract: A pressure transmitter with a hermetically sealed housing surrounding a cavity that is filled with a gas that is free of integrated circuit contaminants. A sensor circuit including an integrated circuit is placed in the cavity and a gas fill port on the housing is sealed. The sensor circuit is electrically adjustable from outside the pressure transmitter and the integrated circuit is protected from contaminated atmospheres outside the pressure transmitter.

Abstract: A modular process transmitter having a scalable EMI/RFI filtering architecture includes a unitized sensor module and a transmitter module. The unitized sensor module is adapted to operate as a stand-alone process transmitter. The transmitter module can couple to the unitized sensor module to expand the capabilities of the unitized sensor module. The unitized sensor module includes a sensor housing, a sensor circuit and a removable sensor EMI/RFI filtering circuit. The sensor circuit provides a sensor output in accordance with either a local format or a first communication protocol. The sensor EMI/RFI filtering circuit filters noise in accordance with the first communication protocol. The transmitter module includes a transmitter module housing, a communications circuit, and a transmitter module EMI/RFI filtering circuit.

Abstract: Disclosed is a process control transmitter having an externally accessible DC circuit common that eliminates the need to perform level shifting of signals communicated between the transmitter and external processing electronics. The process control transmitter includes first, second and third terminals which feedthrough a housing. Circuitry contained in the housing is coupled to the first, second and third terminals and is adapted to communicate information to external processing electronics through the second and third terminals using a digital signal that is regulated relative to a DC common that is coupled to the second terminal. External processing electronics can couple to the second and third terminals and interpret the digital signal without having to perform level-shifting adjustments.

Abstract: A pressure sensor module and method for pre-installation without a converter module. The pressure sensor module is hermetically sealed and can remain undamaged in an installation environment without a converter module. The pressure sensor module can be assembled later with a converter module in the installation environment. The pressure sensor module includes an isolator, a pressure sensor and a circuit that provides a bus for energization, control and a digital pressure output. The bus is connected to contacts in an insulating feedthrough. An integrally formed hermetic external support structure surrounds the pressure sensor and circuit. The hermetic external support structure has a threaded process fluid inlet around the isolator, and a threaded support sleeve supporting the feedthrough.

Abstract: A two-wire industrial process control transmitter includes a sensor, at least two integrated circuits, and a level shift circuit. The first integrated circuit contains the analog measurement circuit that includes a sensor detection circuit and the analog portion of a digital-to-analog convertor. The second integrated circuit contains the digital system circuit that includes a modem and the digital portion of the analog-to-digital convertor. The first and second ICs may be powered at different voltage levels to maximize the power of the analog circuit and improve resolution. Alternatively, the ICs may be powered at the same voltage level, but the digital circuits are divided among several stacked dies to minimize the voltage for each digital circuit. In either case, the level shifting circuit shifts the voltage level between the analog and digital circuits.

Abstract: Conversion circuitry for use in a process control system is adapted for coupling to a primary process control loop. Digital receiver circuitry in the conversion circuitry receives a digital signal transmitted over the primary process control loop from a field transmitter and responsively provides a digital output. A microprocessor receives the digital output and responsively provides a secondary loop control output. Secondary loop control circuitry for coupling to a secondary process control loop receives the secondary loop control output from the microprocessor and responsively controls current flowing through the secondary process control loop. The current flowing through the secondary process control loop is related to the digital signal transmitted by the field transmitter.