smart transducer interface standard - ieee 1451 september 24, 2002sensors expo, boston1 proposed...
TRANSCRIPT
September 24, 2002
Sensors Expo, Boston 1
Smart Transducer Interface Standard - IEEE 1451
Proposed Changes to the Current IEEE 1451 Overall Architecture
Robert N. Johnson
Telemonitor, Inc.
September 24, 2002
September 24, 2002
Sensors Expo, Boston 2
Smart Transducer Interface Standard - IEEE 1451
Outline
Review goals of IEEE 1451 Background Situation What should we standardize? Proposed “dot zero” standard Expected results Next Steps
September 24, 2002
Sensors Expo, Boston 3
Smart Transducer Interface Standard - IEEE 1451
Main goals for IEEE 1451
Develop network independent and vendor independent transducer interfaces.
Allow transducers to be replaced and/or moved with minimum effort.
Eliminate error prone, manual system configuration steps. Support a general transducer data, control, timing,
configuration and calibration model. Develop Transducer Electronic Data Sheets that remain
together with the transducer during normal operation.
September 24, 2002
Sensors Expo, Boston 4
Smart Transducer Interface Standard - IEEE 1451
First the Earth cooled...
1994--First “Smart Sensor Interface Standards Workshop” held at NIST resulting in study group for standard
1995--Study group forms two working groups: P1451.1 for the network processor model and P1451.2 for the transducer to microprocessor interface
1997--IEEE 1451.2-1997 is approved. P1451.3 and P1451.4 working groups agree to maintain major IEEE 1451 family traits
2001--IEEE P1451.5 study group starts work on a standard for wireless sensor
2002--Proposals made to coordinate the TEDS and operational models of the family of IEEE P1451 standards to improve compatibility and reduce duplication of effort
September 24, 2002
Sensors Expo, Boston 5
Smart Transducer Interface Standard - IEEE 1451
1997 Architecture Guidelines
Interfaces are defined, not modules Modules may support multiple interfaces
Higher-level standards must be maintained At that time this meant providing a way to generate a
1451.2 TEDS Partitioning is invisible beyond the immediate interface
A module or network device should not have to know or care what interfaces are implemented past the immediate one
Hot swaps must be allowed and passed on Each standard must support a way to simulate the “hot
swap” of a transducer and force the network-side device to accept the updated TEDS
September 24, 2002
Sensors Expo, Boston 6
Smart Transducer Interface Standard - IEEE 1451
Present Situation
The IEEE 1451 family of standards has established several valuable basic principles of smart transducers, the most important of which is the TEDS
Different physical interfaces are needed by different applications, and more will be needed in the future.
Unless guidance and coordination is provided, we will duplicate efforts and end up with incompatible devices in the standards family.
Now is the time to address this issue; IEEE 1451.1 and 1451.2 are up for revision and renewal, and the proposed standards P1451.3, P1451.4, and P1451.5 are not yet approved.
September 24, 2002
Sensors Expo, Boston 7
Smart Transducer Interface Standard - IEEE 1451
Core Values of the IEEE 1451 Family
Extensible Transducer Electronic Data Sheet (TEDS) General calibration/correction model for transducers Data models based on common standards such as IEEE
floating point numbers Physical units representation based on SI units Control and operation models for different kinds of
transducers Flexible correction engine concept All of the above must be common in order to have a basis
for a common TEDS
September 24, 2002
Sensors Expo, Boston 8
Smart Transducer Interface Standard - IEEE 1451
Power of TEDS plus correction engine
Data Channels
No. Property Type Units Minimum Maximum1 Temperature Sensor K 233.15 (-40° C) 358.15 (85° C)2 Roll Zero Actuator radians -1.57 (-90°) 1.57 (90°)3 Pitch Zero Actuator radians -1.57 (-90°) 1.57 (90°)4 Roll Zero Sensor radians -1.57 (-90°) 1.57 (90°)5 Pitch Zero Sensor radians -1.57 (-90°) 1.57 (90°)6 X Acceleration Sensor m/s2 -19.6 (-2 g) 19.6 (2 g)7 Y Acceleration Sensor m/s2 -19.6 (-2 g) 19.6 (2 g)8 Roll (about X) Sensor radians -1.31 (-75°) 1.31 (75°)9 Pitch (about Y) Sensor radians -1.31 (-75°) 1.31 (75°)
Multi-channel acceleration/tilt sensor:• Hardware channels for temperature and acceleration• Correction engine performs temperature compensation• Virtual actuators for zero correction• Virtual sensors for tilt (roll and pitch)• Correction engine converts to angle• Number order of channels is important
September 24, 2002
Sensors Expo, Boston 9
Smart Transducer Interface Standard - IEEE 1451
It’s the TEDS…!
Industry Extension TEDS
Industry Extension TEDS
Meta-TEDS (mandatory)
Industry Extension TEDS
End Users’ Application specific TEDS
Meta-ID TEDS
Machine readable Human readable Application specific
Future extensions
Channel TEDS (mandatory)
Calibration TEDS
Channel ID TEDS
Calibration ID TEDS
September 24, 2002
Sensors Expo, Boston 10
Smart Transducer Interface Standard - IEEE 1451
Partition the TEDS
New Meta TEDS
New Channel TEDS
Move physical interface related fields
New Physical Interface Meta TEDS
New Physical Interface Channel TEDS
Meta-ID TEDS
Channel-ID TEDSOther TEDS blocks can remain the same.
Supports use of different physical layers....
September 24, 2002
Sensors Expo, Boston 11
Smart Transducer Interface Standard - IEEE 1451
Proposed IEEE P1451.0 TEDS Architecture
Industry Extension TEDS
Industry Extension TEDS
Meta-TEDS (mandatory)
Industry Extension TEDS
End Users’ Application specific TEDS
Meta-ID TEDS
Machine readable Human readable Application specific
Future extensions
Channel TEDS (mandatory)
Calibration TEDS
Channel ID TEDS
Calibration ID TEDS
Physical layer Meta-TEDS(Dot-X specific)
Physical layer Channel-TEDS(Dot-X specific)
Everything not “Dot-X specific” is defined in IEEE P1451.0
September 24, 2002
Sensors Expo, Boston 12
Smart Transducer Interface Standard - IEEE 1451
What About IEEE P1451.4?
The compact TEDS proposed for IEEE P1451.4 cannot include a complete IEEE P1451.0 TEDS, although a template file can provide most of the content
Also, since the data for a P1451.4 device is analog, a lot of the TEDS content is not applicable
BUT, the module that the P1451.4 device connects to can provide the translation to the full P1451.0 content in addition to the conversion between digital and analog
The important thing is that we coordinate such things as units, data representation, correction engine, etc. for true family compatibility
Properly done, other network-side devices need not know if the transducer is P1451.4 or another flavor
September 24, 2002
Sensors Expo, Boston 13
Smart Transducer Interface Standard - IEEE 1451
Results of IEEE P1451.0
Reduction in duplication of effort Commonality and compatibility cross the entire IEEE 1451
family of standards Common network-side view of all devices Ease of adding additional physical media when they are
needed in the future The proposed IEEE P1451.0 standardizes the message,
not the medium
September 24, 2002
Sensors Expo, Boston 14
Smart Transducer Interface Standard - IEEE 1451
What Next?
Form an IEEE P1451.0 study group Coordinate common elements with chairs of all the existing
working groups Review existing and proposed dot-x standards for impact Submit a Project Authorization Request to IEEE and form a
working group Write a draft standard We need to act quickly and your input and participation can
help
September 24, 2002
Sensors Expo, Boston 15
Smart Transducer Interface Standard - IEEE 1451
Questions/Comments?