DEVELOPMENT OF IEEE 1451.1/1451.4 COMPATIBLE NCAP

Abstract

Many instrumentation and control implementation are currently available that allow transducers to be accessed over a network. To meet the need of more specific, reliable and interoperable systems, utilizing the existing control network technologies (wired or wireless), Institute of Electrical and Electronics Engineers (IEEE) 1451 developed a family of standardized methods for interfacing smart transducers to control networks. The IEEE 1451 family of standards defines a set of common communication interfaces for connecting smart transducers (sensors or actuators) to microprocessor-based systems, instruments, and networks in a network-independent environment. The working group of IEEE 1451.4, which belongs to the IEEE 1451 family, created the standard that has proved to be a boon to the legacy analog transducers for communication by them over digital bus, with add-on self-identification capabilities in the form of Transducer Electronics Data Sheet (TEDS). This dissertation work proposes an architecture of sensor network based on IEEE 1451.4 and IEEE 1451.1 standards, utilizing the features of a readily available microcontroller, to support the popular interfaces including Recommended Standard 232 (RS 232), Universal Synchronous Asynchronous Receiver/Transmitter (USART) and Serial Peripheral Interface (SPI). It describes the development and implementation of such a network based on IEEE 1451.1 and IEEE 1451.4/RS 232. The sensor network consists of Network Capable Application Processor (NCAP) and Mixed-Mode Interface (MMI) with an IEEE 1451.4/RS 232 interface. The compact TEDS defined for the standard is implemented on the EEPROM of a PIC microcontroller. The resulting system is a low cost solution to add IEEE 1451.4 compatibility to legacy analog transducer so that they can also communicate over a digital bus and get self-identification capability.