P1451.2 Working Group
Sensor-networking is a fast growing technology. Today the
transducer industry is dominated by analog transducers and interfacing these
transducers to a measurement and control system is a major undertaking and
very costly. Multiple control networking solutions are emerging, each requiring
a separate and significant effort on the part of transducer manufacturers.
Nonetheless, networked transducers offer significant
advantages to users, such as: introduction of self identification of sensors to
the network or system, self-documentation, improved accuracy and reliability
using digital communication, enhanced product functionality (e.g., diagnostics,
multi-variable sensors, remote programmability), cost
reductions in wiring and installation, in process design cycle, and in
commissioning time. All these are significant contributions to productivity
improvement and will benefit producers, vendors, system integrators, and users.
However, there is currently no defined common digital
communication interface standard between transducers and network capable
application processors (NCAPs). Each transducer
manufacturer has to build its own interfaces. Transducer manufacturers currently
cannot afford to support several control networks. A project designed as IEEE
1451.2, Standard for a Smart Transducer Interface for Sensors and Actuators -
Transducer to Microprocessor Communication Protocol and Transducer Electronics
Data Sheet (TEDS) and its Formats, is to address these issues.
|
The objective of this
project is to simplify the development of networked transducers by
defining the hardware and software blocks that do not depend on individual
control networks. This project is to develop a standard hardware interface
to connect transducers to network-capable application processors or
microprocessors. A Transducer Electronic Data Sheet and its data
formats are defined to provide a standard way of describing transducers to
measurement and control systems. The project defines a communication
protocol for the digital interface. This protocol is used to access the
TEDS, read sensor measurements and send digital settings to actuators. The
digital interface is usable by all types of sensors and actuators.
|
|
Figure 1 shows an example STIM, consisting of a sensor, a
TEDS and associated electronics (on a small PC board) for implementing the
1451.2 digital interfaces. Figure 2 shows a block diagram of the 1451.2
Interface.
Figure 2: Block Diagram of the 1451.2
Components
Status:
The IEEE
Standards Office has approved the IEEE 1451.2 as a full-use standard, IEEE Std 1451.2 - 1997. The standard is being revised in the
working group.
The IEEE 1451.2 Standard can be
purchased from IEEE at:
http://standards.ieee.org/catalog/olis/index.html
More information about IEEE 1451.2 being revised can be found at:
http://grouper.ieee.org/groups/1451/2/