In this paper, an experimental industry plant for water purification was created based on the PcVue SCADA interface and the Modbus TCP industrial communication protocol. After implementing the experimental water purification industry plant, an analysis of the Modbus TCP industrial communication protocol security was conducted, as well as the process of risk analysis of the plant on the basis of the IEC 62443 Standard. The results of the risk analysis define critical vulnerabilities of the experimental plant, and in the later parts of the research there is a list of suggested solutions for the given vulnerabilities, paying special attention to the technical measures needed to achieve the desired protection level. The policies and procedures within the plant are based on the Standard IEC 62443-2-1: Establishing an industrial automation and control system security program, and the Standard IEC TR 62443-2-3: Patch management in the IACS environment, while the technical measures are based on the IEC TR 62443-3-1: Security technologies for IACS systems. As the first technical tool used to increase the plant's security, the implementation of the managed switch with settings adjusted in order to increase cybernetic security of SuC is pointed out. Another tool which stands out is the intrusion detection system (IDS) for the communication system, which enables meeting the requirements of cybersecurity presented in the Standard IEC 62443-3-3:2020, if adjusted correctly. The features of each of the technical tools implemented in the plant were assessed by carrying out simple attacks of attackers located within SuC perimeter. The final part of the paper consists of a review of the conducted analysis, methods for increasing security and a report on the security requirements specifications (CRS).