IoT architecture
The cloud includes compute and storage mechanisms together with applications including analytics, reporting, control and user interfaces. The user interfaces may actually live at the edge and are often combined with sensors as in the case of smart phones.
The network is the means by which the components of the architecture are connected together. This connectivity is built on IP based protocols, some of which are conventional protocols such as HTTP with others being more specialized protocols designed specifically to enable IoT-based applications involving large amounts of data collection and distribution.
The edge consists of the “Things” in the Internet of Things such as sensors, actuators, and controllers. In some cases these devices are connected directly to the network via 3G/4G cellular or Wi-Fi. In other cases an intermediary, an edge gateway, provides connectivity to one or more devices that support only local connectivity.
IIoT Architecture
In the case of the IIoT, the applications running against cloud-based storage include applications geared toward industrial enterprises such as planning/scheduling, optimization, and engineering.
This model provides an overview of the general structure of IIoT-based systems. This is not a one-size-fits-all model. There will be variations on this architecture for specific types of systems and customer sites. In some cases the cloud environment may be deployed on premise (either at the customer’s site or in the customer’s data center).
One of the main differences between IoT and IIoT architectures concerns the nature of the edge computing environment. In the IIoT the edge computing environment provides the opportunity to address key requirements in the areas of performance and robustness needed in industrial process control. Another significant characteristic of the edge computing environment in the IIoT that sets it apart from the IoT is a high degree of heterogeneity in the devices used and the protocols with which they communicate.
Purdue Enterprise Reference Architecture model on the left and IoT Reference Model on the right
Applying an IIoT architecture to an industrial enterprise requires reconciling these two different organizational structures so that the key architectural qualities provided by the Purdue model (safety, security, reliability, efficiency) are maintained and enhanced within an IIoT-based structure.
In general, moving functionality to either the cloud or the edge represents a tradeoff amongst a number of system qualities. For example, moving functionality to the edge can improve performance and reliability at the expense of having to provision and manage functionality distributed across a large number of devices. On the other hand, moving functionality to the cloud makes it easier to install, scale up, upgrade, and retire at the expense of the functionality being remote from the devices and controllers on which the functionality may depend.