Eugene Song, another expert speaker at Sensors Converge 2023, will speak on smart sensor and actuator standards and interoperability. Here, the electronics engineer at NIST describes for Fierce Electronics the basics behind his complex work.
Q: What is a “smart” sensor and how can it be used?
Song: A smart sensor device converts a physical, biological, or chemical parameter into an electrical signal, and provides functions beyond those necessary for generating a correct representation of a sensed quantity (e.g., sensing function). Smart sensors have more intelligent capabilities than dumb ones among other basics. Here are examples of functions of smart sensors:
· Signal/data processing & conversion
· Time & synchronization
· Network communication
· Metadata (Sensor electronic datasheet)
· Self-description
· Self-identification
· Self-diagnostics
· Self-testing
· Self-validation
· Self-aware location
· Multiple-sensing and data fusion, and decision-making
Q: What are some smart transducer interface standards for sensors and actuators in IEEE 1451?
Song: The IEEE 1451 family of standards for smart transducer (sensors and/or actuators) interfaces define communication interfaces specifications for sensor and actuator networks. IEEE P1451.0 Standard, a core standard of the IEEE 1451 family, defines common functions, network services, transducer services, and transducer electronic datasheet (TEDS) formats to achieve sensor and actuator data interoperability for IoT, IIOT and CPS applications.
1) Transducer Interface standards between sensors & actuators and sensor network gateway:
· IEEE 1451.2 standard defines the digital interface for connecting transducers to microprocessors.
· IEEE 1451.4 standard defines a mixed-mode interface for smart transducers.
· IEEE 1451.5 standard defines the IEEE 802.11, BlueTooth, ZigBee, and 6LowPAN Wireless Interface based on the IEEE P1451.0 transducer services.
· IEEE P1451.5.5 standard defines the LoRaWAN Wireless Interface based on the IEEE P1451.0 transducer services.
· IEEE P1451.5.6 standard defines the SigFox Wireless Interface based on the IEEE P1451.0 transducer services.
· IEEE P1451.5.10 standard defines the NB-IoT Wireless Interface based on the IEEE P1451.0 transducer services.
2) Network interface standards between sensor network gateways and IoT applications:
· IEEE P1451.1.4 standard defines the XMPP interface based on the IEEE P1451.0 network services.
· IEEE P1451.1.5 standard defines the SNMP interface based on the IEEE P1451.0 network services.
· IEEE P1451.1.6 standard defines the MQTT interface based on the IEEE P1451.0 network services.
3) Harmonization of Internet of Things (IoT) Devices and Systems:
· IEEE P1451.99 standard defines a method for data sharing, interoperability, and security of messages over a network, where sensors, actuators and other IoT devices can interoperate, regardless of underlying communications technology.
Q: Standards help with interoperability…What was missing in the past…can you offer a little history?
Song: In the past, there was a lack of sensor and actuator interface standardization to support interoperability across different products and systems provided by different vendors and manufacturers.
· This lack of sensor and actuator interface standardization made it difficult for different sensor and actuator products and systems from different manufacturers or vendors to communicate with each other and working together, thus in some ways hindering innovation in industries.
· There have been numerous efforts to develop standards and protocols that help promote or achieve interoperability across IoT devices and systems, such TCP/IP, Bluetooth, ZigBee, 802.11, etc. However, here is what has been missing to help achieve Interoperability:
o Need robust standards (clear definitions and specifications defined in the standards).
o Need new standards or old standards updated or revised with advanced technologies (e.g., LoRa WAN, NB-IoT, 5G/6G, …) and new applications (e.g., IoT/IIoT/CPS).
o Need fundamental methodologies for interoperability modeling, measurement, and assessment.
o Need interoperability test and plugfest activities participated by vendors and manufacturers.
o Need testing & certification program to support and achieve the goal of interoperability.
Q: Standard work involves many steps. Can you describe the steps and how they pertain to IEEE 1451.0, which has not yet been published or seen widespread adoption?
Song: The development of a new standard involves six stages:
1) Initiating and approval of a standard project.
2) Forming a standard Working Group (WG).
3) Drafting a set of technical specifications.
4) Reviewing and balloting processes to finalize as a standard.
5) Approving and publishing a standard through IEEE/ISO/IEC.
6) Maintaining a standard (revising or withdrawing).
Once the standard has been completed, the timeline for products to emerge based on the standard can depend on a variety of factors including level of adoption and implementation by industry stakeholders, the pace of technical development, and the availability of supporting infrastructure and resources. It could happen any time:
· When draft specification is done before balloting.
· After balloting and before approval of the standard.
· After approval and publication of the standard.
The revision of the IEEE 1451.0 standard started in 2017. The IEEE P1451.0 draft was completed and started balloting this month. We expect the standard to be approved by the IEEE Standards Board sometime early next year.
Q: Do most standards go far enough to satisfy existing problems, especially with cyber physical systems? What’s the reaction from the vendor and researcher communities broadly?
Song: In some cases, the standard can be highly effective in addressing and satisfy existing problems and promoting best practices. The standard will be widely adopted by vendors and manufacturers and help improve quality of their products.
However, in other cases, the standard may not be sufficient to address and satisfy to solve existing problems. In this case, the standard needs to be modified/updated based on new technologies and approaches to improve the standard, or in the worst-case scenario, withdrawal of the standards project.
Reactions from vendors to standards can also vary depending on the specific standard. In one case, vendors or manufacturers may be supporting the standards that promote interoperability and compatibility between different products and systems. In another case, vendors or manufacturers may view standards as a burden or a barrier to innovation. Thus, the standard should be modified to be well -efined to achieve the goal of products and systems interoperability yet leave room for innovation.
Similarly, researchers may view the standard as a useful tool for promoting best practices and ensuring consistency in research methodologies. However, researchers may view standards as overly prescriptive or limiting, and may prefer more flexible approaches to do research and development.
Q: What are some of the challenges that sensor application developers and end users are facing?
Song: Challenges for sensor application developers:
· Need to understand and interpret the technical aspects of the standard.
· Need to understand and interpret the business aspects (marketing) of the standard.
· Need to design and develop products to implement the standard correctly to achieve the goal of interoperability.
· Need to participate in interoperability test or plugfest activities to assure sensor’s interoperability with other products provided by different vendors.
Challenges for sensor end users:
· Need to understand the functionalities and capabilities of the standard.
· Need to overview and analyze the products in the marketplace based on the standard.
· Need guidelines to select the right products in the marketplace based on the standard to be implemented to achieve interoperability and reduce integration costs of sensor applications.
Eugene Song is an electronics engineer for the IoT devices and infrastructure group at the National Institute Standards and Technology. He chairs the IEEE 1451.0 Standards Working Group to develop an interface standard for smart sensors and actuators for sensor-based networks suitable for SG/IoT/CPS applications. He will speak on “Smart Sensor and Actuator Standards and Interoperability for Iot, IIoT and CPS” at 9:25 a.m. PT on Wednesday June 21 at Sensors Converge 2023 in Santa Clara, California. Register online for the event.