What is a sensor?

 

A sensor is a device that measures a physical attribute or a physical event.  It outputs a functional reading of that measurement as an electrical, optical or digital signal.  That signal is data that can be transformed by other devices into information.  The information can be used by either intelligent devices or monitoring individuals to make intelligent decisions and maintain or change a course of action.

 

What are smart sensors?

 

A smart sensor is simply one that handles its own acquisition and conversion of data into a calibrated result in the units of the physical attribute being measured.  For example, a traditional thermocouple simply provided an analog voltage output.  The voltmeter was responsible for taking this voltage and transforming it into a meaningful temperature measurement through a set of fairly complex algorithms as well as an analog to digital acquisition.

 

A smart sensor would do all that internally and simply provide a temperature number as data.  Smart sensors do not make judgments on the data collected unless that data goes out of range for the sensor.

 

 

Why IEEE 1451?

 

There are four compelling reasons for developing a plug and play standard for smart sensors.  IEEE 1451 is a developing standard that can make all complying sensors, instruments and systems work together with relative ease.  So far, only IEEE 1451.4 compliant sensors are widely available but commercial applications for the full standard set are in development and will be introduced within the next year.

 

1. There are more than 3,000 global sensor manufacturers.  Trying to use a variety of sensors from a number of different manufacturers together in a data acquisition system can be very complex and require expensive customization by the integration team.
2. A conventional sensor system has a lot of analog wiring and extensive switching.  IEEE 1451 systems will greatly simplify development and installation of smart sensor systems.
3. IEEE 1451 compliant systems will cost significantly less to install than conventional sensor systems.
4. Intechno Consulting forecasts the global sensor to grow from $32.5 Billion a year in 1998 to $50.6 Billion a year in 2008.  Some of the big players, such as Intel, are betting that this is “the next big thing” to drive both information technology and corporate profits. Several factors make IEEE 1451 the right standard at the right time to capitalize on this extremely high growth rate.  Semiconductor manufacturing techniques can make a wide variety of sensors far easier and cheaper to manufacture in quantity.  These techniques can also be applied to nano development and manufacturing.  Low-power and power scavenging sensors can be wirelessly deployed, reducing the cost of installation.  IEEE 1451 can enable networks of smart sensors to communicate and even to set up ad hoc networks.  

 

 

What is IEEE 1451?

 

IEEE 1451 is the standard under development for “smart sensors” by the Institute of Electrical and Electronics Engineers, a non-profit professional association of more than 360,000 members throughout the world.  Find them at www.ieee.org . 

 

What does IEEE 1451 do?  What is it going to do?  Why is it important?

 

IEEE 1451 is a planned set of standards for smart sensors that will make it easier and cheaper to deploy a wide variety of sensors. 

 

• IEEE 1451.0 – This portion of the standard defines the structure of the TEDS (Transducer Electronic Data Sheets) the interface between .1 and .X, message exchange protocols and the command set for the transducers.
• IEEE 1451.1 – Specifies collecting and distributing information over a conventional IP network.
• IEEE 1451.2 – Wired transducer interface – 12 wire bus working on a revision which will put IEEE 1451 on RS- 232, RS-485 and USB.
• IEEE 1451.3  - This is the information to make multi-drop IEEE 1451 sensors work within a network.
• IEEE 1451.4 – This portion of the standard specifies the requirements for TEDS (Transducer Electronic Data Sheets).  This is software only.
• IEEE 1451.5 – This section of the standard specifies information that will enable 1451 compliant sensors and devices to communicate wirelessly, eliminating the monetary and time costs of installing cables to acquisition points.  The IEEE is currently working on three different standards, 802.11, Bluetooth and Zigbee.
• IEEE 1451.6 – This is the information required for the CAN (consolidated auto network) bus.

 

Currently, IEEE 1451.1 and IEEE 1451.4 have become published standards.  IEEE 1451.3 has been approved and is awaiting publication.  IEEE 1451.2 is awaiting revision.  IEEE 1451.4 has commercially available products, largely because National Instruments has enthusiastically backed this standard and is encouraging its clients and alliance members to take advantage of the synergies it provides. 

 

Why is Complete Test participating in IEEE 1451 standard development?

 

Complete Test has been very interested in the development of test and measurement.  After several years of research, we determined that one of the most promising areas of development for test and measurement is smart sensors.  IEEE 1451 promises excellent communications, data reduction and intelligent data development.  In short, 1451 promises to save money on deployment, save money in operations and provide actionable intelligence so that users are not buried in data but have the opportunity to make efficient, effective and intelligent decisions based on accurate and analyzed data.

 

Complete Test has two engineers serving on IEEE 1451 working groups to help define these standards.

Vicky Sweetser and Jay Nemeth-Johannes both serve on the following:

• IEEE P1451.0 Common Functions, Communications Protocols and TEDS Formats Working Group
• IEEE P1451.5 Wireless Sensor Interface Working Group

Jay has had a long term interest in developing workable standards. Vicky is our hardware standards development guru.  

 

Complete Test is pleased to be a member of the National Instruments Alliance.  You can find their 1451.4 information at http://www.ni.com/pnp/ .  Their TEDS (transducer electronic data sheets) let your Data Acquisition System find and automatically configure sensors, saving time and reducing the possibility of human error.

 

Complete Test is developing several commercial products for IEEE 1451. We also provide consulting services to help your products integrate into IEEE 1451. Feel free to contact us if you have questions about this promising technology.

 

Glossary

 

NCAP – Network Capable Application Processor

TIM – Transducer Interface Module

TEDS - Transducer Electronic Data Sheets