Reliable Network Communication

Abstract: The Target Positioning Sensor (TPS) is used by cranes to locate containers in ports and on cargo ships. The reliability of the communication network between the TPS and the Programmable Logic Controller (PLC) is important to optimise the productivity of the container terminal. Lost data messages between the network devices will lead to delays and production loss for the terminal. The main goal of this thesis project is to make the Ethernet-based network between the TPS and the PLC more reliable. The current sensor network protocol uses the User Datagram Protocol (UDP), and the project aims to replace that with the Transport Control Protocol (TCP). This includes designing a new message handling application and performing case studies on how to best handle compatibility issues between the TPS and the PLC, to improve the longevity of the application. The case studies led to considering an adaptable behaviour toward future software updates in different parts of the network. An application which used TCP to communicate between a PC and a PLC was developed, intended to be used as a reference during future integration into the actual sensor network. The TCP application works but needs to be improved before being implemented in a real system. In addition, the project also looked into Time-Sensitive Networking, which is a method of increasing link capacity and reliability in time-sensitive network implementations. This was done through a literature study on the IEEE Time-Sensitive Networking Standard, which showed that the application of the standard could be beneficial if more sensors are added to the network of if the sampling frequency of the TPS is increased.