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Traditionally, the 4–20mA analog signal used in industry to interface sensors in distributed process control has been replaced with relatively simple digital networks, called “field-buses”, and recently by Ethernet. In this work, three interfaces for a simple sensor, based on the same architecture and microcontroller, have been implemented and tested: Profibus-DP, CANbus2.0B and Ethernet IEEE802.3. The experimental results show that the Ethernet interface, although less efficient than field-bus interfaces, requires about the same resources, in terms of computing power and memory space for code and data storage. As an Internet-capable sensor could be virtually reached from everywhere, for remote control and diagnosis, the feasibility of an Internet interface has been investigated. A full-compliant implementation of high-level protocols as TCP/IP or HTTP needs many resources to be implemented, resulting too …