Abstract: A field device includes diagnostic circuitry adapted to measure a characteristic related to a process control and measurement system. The measured characteristic is used to provide a diagnostic output indicative of a condition of the process control and measurement system. The measured characteristic can be provided to a diagnostic module that operates upon the measured characteristic to predict, or otherwise model, a condition of the process control and measurement system.

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 field device includes diagnostic circuitry adapted to measure a characteristic related to a process control and measurement system. The measured characteristic is used to provide a diagnostic output indicative of a condition of the process control and measurement system. The measured characteristic can be provided to a diagnostic module that operates upon the measured characteristic to predict, or otherwise model, a condition of the process control and measurement system.

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.