Читать книгу Industry 4.0 Vision for the Supply of Energy and Materials - Группа авторов - Страница 57

IIoT involves diverse industrial assets such as manufacturing control systems, industrial process controllers, devices, and components. These controllers and equipment are distributed throughout an industrial site and use both proprietary and open protocols for communication. Basically, proprietary protocols belong to a particular product line within the systems [176, 177, 178], while open protocols are governed by standard organizations and utilized across products. Considering the advent of communication technologies and various protocols for both proprietary and open standards, there are technical challenges in the interconnection of different industrial protocols and assets. This calls for the creation of systems and techniques that integrate different protocol interfaces in manufacturing and industrial processes and that allow the interoperation of devices, equipment, and services from various vendors and operators. In this context, Open Platform Communication-Unified Architecture (OPC-UA¹⁶) is a possible solution that offers interconnection and easy integration of newer standards (wired and wireless) and middleware technologies in Industry 4.0 [179]. Moreover, a communication interface for IIoT is proposed in [180] that provides communication among programmable controllers and devices for operating and monitoring processes and equipment.

Design of protocol interface could be discussed in horizontal and vertical directions [55]. Figure 1.1 indicates the concept of integration in Industry 4.0. Typically, horizontal protocol interfaces provide interconnectivity among nodes to meet certain network functionalities such as clock synchronization among nodes. Time-sensitive network (TSN) protocols are examples of such interfaces that provide real-time connectivity for mission-critical and time-sensitive use cases [162, 181]. On the other hand, vertical protocol interfaces assist in secure data and service integration and offer consistent information flow via protocol stacks [55]. IETF has released encapsulation and compression techniques that unify such operations for devices [182]. 6LoWPAN is an example of networking technology from IETF that determines fragmentation mechanism for IPv6 headers [183].