IIoT system architecture, in its simplistic view, consists of three tiers (as the following diagram illustrates):
- Tier 1: Devices
- Tier 2: The Edge Gateway
- Tier 3: The cloud
Three-tier architecture of a typical IIoT end-to-end application
Tier 1 of the IIoT architecture consists of networked components, typically sensors and actuators, from the IIoT equipment, which use protocols such as Modbus, Zigbee, or proprietary protocols, to connect to an Edge Gateway. Tier 2 includes sensor data aggregation systems called Edge Gateways that provide functionality, such as preprocessing of the data, securing connectivity to cloud, and using systems such as WebSockets, the event hub, and, even in some cases, edge analytics or fog computing. Tier 3 includes the cloud application built for IIoT using the microservices architecture, which is usually polyglot and inherently...