IEEE 1451.2: An interpretation and example implementation

The IEEE 1451 set of standards define an architecture which allows sensor and actuator nodes to connect into a live distributed control network, in a true 'plug and play' fashion. The standard itself is composed of four parts. IEEE 1451.1 through to IEEE 1451.4. Although the extent of each part is well defined currently only the first two parts (IEEE 1451.1 and IEEE 1451.2) exist as fully released, balloted standards. This paper provides an explanatory oveview of the various parts of the IEEE 1451 standard. A target hardware environment for an IEEE 1451.2 STIM (Standard Transducer Interface Module) is introduced, in the guise of the Analog Devices ADuC812 Microconverter chip, which was designed abinitio to meet the IEEE 1451.2 standard hardware requirements. A software environment has been developed by the authors to realise the full STIM functionality in the ADuC812. This software is designed on a modular basis, and it is mapped to the ADuC812 hardware to realise a fully compliant IEEE 1451.2 STIM. Based on the implementation experience the STIM resource requirements in terms of program and data memory are defined. The software model is composed and presented, so that a functional breakdown of the IEEE 1451.2 implementation can be extracted. The software code described can be easily ported to various proprietary hardware platforms. To provide a meaningful demonstration, this STIM implementation is interfaced to a HP BFOOT-66501 NCAP to demonstrate a remote temperature control application, operating over the World-Wide-Web (via an Ethernet network). The STIM implementation described in this paper is independent of any particular type of host network, as the IEEE 1451 standard is intended to fit around any existing network solution.