1.1 Proposal
1.2.5 Research Methodology
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The research methodology used in the project is Applied Research Methodology. This research looked at problems the industry, particularly parastatals, face concerning asset lifecycle optimisation. The study also looked at how technology from an embedded systems perspective or Internet of Things perspective can bridge the gap or enhance asset life cycle optimisation and enhance the end-user experience. Much of the research methodology comes from an electronic engineer's tacit knowledge through a long career in asset maintenance.
- 32 - Bridging the gap between a process control system and IoT. PLC, SCADA, and web services.
This research aims to bridge and marry the worlds of software development, embedded systems design, and hardware implementation. This research implements progressive phases of action to achieve proof of concept. It also incorporated low-level programming using the barebones approach and rapid development platforms like Mbed, Cubemax for STM microcontroller devices, and high-level programming in C# in the .net environment and python to implement system integration to enable web visualisation of the devices. Many existing and emerging protocols were investigated to achieve maximum data interoperability without compromising security.
Presenting the data collected, aggregating the data, and presentation and analytics. This research methodology was based on the premise and needed to integrate engineering process control systems, the operational network, and the IT network. The greatest challenge in this research was wearing different caps at the different levels of the data value chain. Technology is evolving rapidly; the challenge is how emerging technology experts keep abreast of all the technologies at the different levels of the data value chain while maintaining a high level of expertise. There are numerous solutions in the modern era, but the challenge is to put together reliable, accurate frameworks and reliable frameworks and will last the test of time and price.
This research can be broken down into three areas viz: Research software techniques.
Researching the hardware as well as the communication interface.
- 33 - 1.2.6 Organisation of the Thesis
This thesis is organised into different chapters for ease of reading and separating the various technologies and modules. The breakdown of the chapters is as per the table of contents.
Chapter 1 is the proposal for this research and some preliminaries of this thesis.
Chapter 2 covers the theoretical research and literature review that was acquired during this project, This chapter
Chapter 3 is the Hardware implementation of the design and supports the technical implementation of the work carried in Chapters 4 and 5.
Chapter 4 is a research published using LoRa Physical layer to parse data to a SCADA system.
Chapter 5 is a research covering visualising data in central gateway and web API from different data sources.
Chapter 6 is the Testing and results of some of the technologies implemented, mainly LoRa Wan Architecture.
Chapter 7 is the conclusion and future work that could emanate from the research.
- 34 -
CHAPTER 2
LITERATURE REVIEW 2.1 Introduction
The inherent need to get data to High-level systems has created an opportunity to investigate available technologies to produce viable and feasible solutions to add to the data value chain. There are presently many vendors in this space capable of supplying appropriate solutions using present IoT technologies but in the form of propriety solutions. In the open- source world, where the key motive is to make data on all levels more interoperable, there is an exponential increase in knowledge and innovations that, if packaged correctly, can lead to innovative solutions to achieve the objectives of this research.
Part of the literature review process was to understand the transition from legacy systems to new modern technology architectures. Data interoperability also required a complete understanding of the sensor-level data value chain to high-level application software. Each transition level of the data value chain has different implementation and technologies that differ in cost and complexity. Sometimes it requires a hybrid solution to provide the correct fix or solution. Much research is conducted in this space, but most of the research undertaken seems to cover off-the-shelf implementations and rapid development platforms.
Even though this seems to be the growing trend, this is also very debilitating as a lot of the building blocks are lost if too much of the research is focused on of-the-self and rapid development platforms.
The literature review of the thesis can be broken up into different modules, just as the thesis is divided into different modules. The literature review, on many occasions, will often present other or similar technologies but may not be implemented in the final proof of concept but was necessary to understand the technology and implement the most appropriate solution/technology in terms of achieving the objectives of this research.
It was necessary to explore hardware, software, and communication protocol options to achieve the outcomes and knowledge to achieve the proof of concept of this research. The literature review purview of the thesis was first to compare the different wireless technologies, namely LoRa physical layer and 2.4Ghz Nrf24l01 radio modules options for
- 35 - transmitting sensor or process controller data in a plant environment for a range greater than 200m, followed by understanding the chosen wireless technology in this case LoRa. Then further investigating the different LoRa options, namely the LoRa node to node Transmission and the LoRa WAN option.
To get the full benefit of the LoRa technology, it was necessary to understand the founding and operational principles of this LPWan technology and its applications and its closest competitors. LPWan technologies also target the IoT world, which implies a level of integration to web-based systems, which also leans the research towards understanding and applying different transport layer protocols to enhance the data value chain from sensor to web visualisation.
Choosing different hardware platforms was also a great challenge from an embedded perspective as there are many options to choose from. In many instances, platforms that researchers and developers are already familiar with are customarily chosen. Familiarity with architecture is usually the key driver in selecting a specific microcontroller type, and this was certainly the case in this research. The platform selected for this research was mainly the STM32 and Arduino(ATMega) microcontroller family.
A literature review was conducted in the various low-level hardware interfaces used in the design and can be categorised as follows:
i. Understanding SPI
ii. 4-20 mA interface into a microcontroller
iii. Reading analogue value using a 0-10V sensor.
iv. Interfacing the LoRa radio Module.
v. Interfacing the nrf24l01 radio module.
vi. Interfacing the enc28j60 Ethernet controller.
vii. Interfacing cell phone modem.
viii. Working with and deploying LoRa wan Gateway R3000 Robustel.
- 36 - A literature review was also conducted for various software modules and communication protocols and frameworks to realise the objectives of this research and can be categorised as follows:
i. Researching communication protocols relating to process control systems like OPC UA, MQTT, COAP
ii. Researching the LoRa Physical layer and LoRa WAN architectures
iii. Exploring frameworks for web visualisation.
iv. Researching SQL frameworks to optimise data visualisation.
The next phase of this research looked at getting data in a modern format like OPC UA and MQTT. The study was also conducted to understand different technologies in this space.
Part of this literature review touches on the OPC UA, MQTT and COAP, and AOQP and how they fit into the IoT space in terms of the data value chain. Some of the low-level interfaces like SPI and DMA were also reviewed.