Temperature compensated field bus sensor interface for applications in process engineering

A robust, high precision sensor interface (SI) for in-situ temperature measurements in process engineering is presented. Wiring and interference are minimized by directly connecting thick film technology based sensing elements (SEs) to the interface PCB. Fully digital calibration, operating temperature compensation and noise canceling are demonstrated. A low-noise supply scheme for a wide range of operating voltages is examined. Parallel operation of up to 120 units on a self-managing CAN field bus is discussed. The protocol for the sensor interface's user-friendly generic serial ACM USB connection is illustrated.