Transducer interface for multichannel wired telemetry in high temperature environment

This paper presents a design of a simple, microcontroller-based interface for a frequency-output transducer, which is a part of a larger multichannel wired telemetry system. The function of the interface is to acquire frequency-modulated data from the transducer, prepare the data in the form suitable for transmission via logging cable, and handle the digital transmission protocol. A specific feature of the telemetry system is its operation in a high temperature environment (up to 180/spl deg/C), which requires high performance from the transducer interface circuit. The presented interface has been designed by combining the use of low-cost commercial components with 'clever' software techniques, as an alternative to the application of expensive high-temperature technologies. Preliminary results have shown that a reliable interfacing of transducers can be obtained, for high temperature, short-term data logging applications.