Introduction to IEEE P1451
Transducers, defined here as sensors or actuators, serve a wide variety
of industry's needs, manufacturing, industrial control, automotive, aerospace,
building, and biomedicine are but a few. Since the transducer market is
very diverse, transducer manufacturers are seeking ways to build low-cost,
networked smart transducers. Many sensor control networks or fieldbus implementations
are currently available, each with its own strengths and weaknesses for
a specific application class. Interfacing the smart transducers to all
of these control networks and supporting the wide variety of protocols
require very significant efforts and are costly to transducer manufacturers.
However, using digital communication schemes, networked transducers can
eliminate a large number of lengthy parallel analog wiring and thus reduces
the installation, maintenance and upgrade costs of measurement and control
systems. And the use of microprocessors to handle the digital communication
has also opened the opportunity for adding intelligence to sensors. One
problem for transducer manufacturers though, is the large number of networks
on the market today. Currently, it is too costly for transducer manufacturers
to make unique smart transducers for each network on the market. Therefor
a universally accepted transducer interface standard, the IEEE P1451 standard,
is proposed to be developed to address these issues.
Objective of IEEE 1451
The objective of this project is to develop a smart transducer interface
standard IEEE 1451. This standard is to make it easier for transducer manufacturers
to develop smart devices and to interface those devices to networks, systems,
and instruments by incorporating existing and emerging sensor- and networking
technologies.
History of IEEE-1451
In September 1993, the National Institute of Standards and Technology (NIST) and the Institute of Electrical and Electronics Engineers (IEEE)'s Technical Committee on Sensor Technology of the Instrumentation and Measurement Society co-sponsored a meeting to discuss smart sensor communication interfaces and the possibility of creating a standard interface. The response was to establish a common communication interface for smart transducers. Since then, a series of five workshops have been held and four technical working groups have been formed to address different aspects of the interface standard. The P1451.1 working group aims at defining a common object model for smart transducers along with interface specifications for the components of the model. The P1451.2 working group aims at defining a smart transducer interface module (STIM), a transducer electronic data sheet (TEDS), and a digital interface to access the data. The P1451.3 working group aims at defining a digital communication interface for distributed multidrop systems. The P1451.4 working group aims at defining a mixed-mode communication protocol for smart transducers. This family of IEEE 1451 standards is designed to work in concert with each other to ease the connectivity of sensors and actuators into a device or field network.
The working groups created the concept of smart sensors to control networks interoperability. This concept of sensor/network interoperability was demonstrated at the two workshops held in conjunction with the two different Sensor Expo in Boston and Chicago.
So far, the project has produced a set of specifications which is approved and published by IEEE as IEEE Std 1451.2-1997, Standard for a Smart Transducer Interface for Sensors and Actuators - Transducer to Microprocessor Communication Protocols and Transducer Electronic Data Sheet (TEDS) Formats. A copy of this standard can be ordered on the IEEE website http://standards.ieee.org/sds/index.html, or from IEEE by calling 1-800-678-4333 (in US and Canada) or 1-732-981-0600 (outside US and Canada) or by fax 1-732-981-9667.