ch5 green book

• Transducers


  Sensors and actuators that are the fundamental core of any M2M or IIoT architecture
• Transducers


  • They are the edge devices of any system and allow us to sense and manipulate our environment
  • They need to be interconnected to communicate with other devices or a central processing machine
• M2M


  Machine-to-machine communication
• IIoT


  Industrial Internet of Things
• M2M and the Industrial Internet of Things share a common reference and their architecture
• Proximity network


  The area that hosts the devices
• The only real evolution between M2M and the Industrial Internet is the sense that the IIoT has Internet connectivity
• The Internet cloud system's intelligence and the interfacing middleware are part of the IIoT rather than an integral part of each IIoT or M2M system
• The essential elements that make up the IIoT and the M2M architectures are fundamental requirements to build interconnected systems
• Devices


  • They can take many shapes and forms
  • Not all devices are the same or have the same complexity or connectivity requirement
  • They can be deployed in many ways (clothing, credit cards, machinery, smartphones, jet engines, even in the body)
  • There is no one-fit system to monitor, manage, and control them
• Transducers


  • Simple, cheap, passive analogue sensors
  • TTL digital sensors and actuators
  • Complex embedded systems
  • Advanced systems on a chip (SoC)
  • Advanced custom proprietary logic built into industrial machines that support their own protocols
• There is no single method of interfacing these devices
• Each device will have their own communication characteristics dependent on their role and this will determine how often and how much data they transmit
• Devices


  • They have limiting physical characteristics such as size and power
  • A device deployed in a remote field location may be self-powered by a small button cell battery that lasts years
  • Alternative power sources like solar or wind provide only very limiting power and are unlikely to be suitable for powering a satellite or 3/4G/LTE radio transmitter
• It is essential when designing interconnecting devices and systems to take into consideration the physical characteristics and performance requirements of each device
• Designing interconnecting systems is not complex, it is simply a case of matching the requirements to the available tools
• Scenarios for connecting IIoT devices

  • Enterprise IoT
  • Consumer IoT
  • Commercial IoT
  • Industrial IoT
• Enterprise IoT


  • IoT devices are typically connected using Ethernet (wired or wireless) connections
  • Devices will be only locally connected and communicate between gateways, back-end systems, and storage devices
  • When Internet connectivity is required, the entity will communicate via an Internet gateway
• Commercial IoT

  • Devices deployed in suburban or rural locations may require direct communication with a service provider's Internet gateway, similar to industrial IoT
• Industrial IoT


  • Many of the M2M communications are required to be in real time
• To understand how to build and interconnect Industrial Internet device networks, you need a deep understanding of how the transducers will communicate with the rest of the world, and of the network's latency and predictability
• Wireless Sensor Network (WSN)

  A local area network of many cheap transducer nodes that are networked in a mesh or star configuration to cover a local area
• WSN nodes


  • They are cheap embedded sensors with limited intelligence that perform a single function
  • They can be deployed in large volumes within a WSN to cover a large strategic area
  • They relay data to their neighbors until it reaches an edge node
  • They are low power so they can run off a battery or harvest energy
  • They generate or consume only small quantities of data
  • They need to connect to an IP-aware edge device to communicate with the rest of the system
• WSN edge node


  • A gateway between the WSN network and typically an IP backhaul network
  • It performs translation and reframing of the local communication protocol to IP
  • It performs aggregation and correlation of data from all the nodes
  • It identifies each WSN node through standard interfaces
  • It performs local processing of the data and filters out unnecessary traffic from traversing the backhaul IP network

  
• WSN network protocols


  • They require low-power communication technology
  • Wi-Fi is not suitable as it requires considerable power and may conflict with existing WLANs
  • IIoT devices use radio technologies with low-power consumption that do not conflict with existing radio broadcasts
• Research and development of IIoT networking technologies is aimed at facilitating the development of low-cost, low-power connectivity solutions
• Low-power IIoT technologies


  • They support the design and creation of very large networks of intelligent and miniature WSN nodes
  • They include research into low-power and efficient radios to allow for several years' of battery life
  • They include research into IoT devices capable of energy harvesting (solar, wind, electromagnetic) as a power source
• Research is also focused on making application protocols and data formats more efficient for low-power devices
• There are trade-offs to consider when designing low-power device networks, such as the frequency (bandwidth), the size of the message being sent, and the technologies and protocols available to minimize radio power/transmit time and preserve battery life
• Not all technologies and protocols fit every IIoT deployment scenario
• Devices connected via mesh or star topology need to communicate effectively with other devices or with the gateway edge device
• Wireless technology must meet required standards for the deployment
• Industry decision-makers are very risk averse and are unlikely to adopt a solution that does not meet existing industry standards
• Vehicle bus


  A specialized internal communications network that interconnects components inside a vehicle
• Vehicle bus protocols


  • They have special requirements for the control of the vehicle and for passenger safety, such as high assurance of message delivery, non-conflicting messages, deterministic time of message delivery, and redundant routing
  • They prioritize low cost and resilience to EMF noise over conventional computer networking technologies
• Vehicle bus protocols


  • Controller Area Network (CAN)
  • Local Interconnect Network (LIN)
• ARINC 664


  An implementation of Avionics Full-Duplex Switched Ethernet used in aircraft
• Aircraft using AFDX


  • B787
  • A400M
  • A380
• IEEE 1451


  A family of Smart Transducer Interface Standards for connecting transducers to microprocessors, instrumentation systems, and control/field networks
• OSI table


  A 7-layer model that determines the structural layers in data communications