Implementing the Industrial IoT Data Flow
In the previous chapters, we looked at how a typical industrial scenario works and at the existing technologies that have been in place since 1990. In this chapter, we are going to understand how to connect this old world to the new IoT world. We will look closely at how to connect and gather industrial data from different devices and data sources. In particular, we will explain the OLE for Process Control (OPC) protocol in detail. We'll start by looking at its original implementation in 1996, based on the Microsoft architecture of Component Object Model (COM) and the Distributed Component Object Model (DCOM), and track its progress right up to the current Unified Architecture (UA), which is based on open and interoperability standards.
We will then go into detail about some concepts that were outlined in the previous chapters. These include high-and low-frequency data, sampling, data filtering, dead bands, data compression, polling, and unsolicited data collection. We will also introduce other concepts related to the collection of industrial data, such as subscription, collection timeouts, temporary storage, and data buffers.
After that, we will look at edge devices in detail to give the reader a comprehensive idea about their role, functionalities in the I-IoT data flow, hardware footprint, software architecture, networking capabilities, and the options that are available in the market. We will also take a look at the emerging models of edge and fog computing.
Following this, we will look at the I-IoT data flow from the perspective of a developer. This will include choosing which industrial device to use to gather industrial data, highlighting their strengths and weaknesses; how to collect the data that comes from sensors and actuators through OPC or fieldbus; how to bubble them to the edge; and, finally, how to transfer them in a reliable way to the cloud.
In this chapter, we will explore the following topics:
- OPC Classic and OPC UA
- The edge and the edge gateway
- Edge and fog computing
- Data sources for the I-IoT
- Edge deployment and I-IoT data flow scenarios