SCADA Communication Real Time Protocols

Abstract

Objectives/Method: SCADA networks are crucial for industrial organizations, and play an important role in real time industrial communication. Today, with the fourth industrial revolution, infrastructures are increasingly connected to the corporate network and to Internet, which makes them more dependent on networks and communication protocols used. This connectivity can help optimize manufacturing and distribution processes while reducing costs, but it also exposes the industrial network to security issues. The purpose of this article is to describe the architecture of SCADA networks and present the most used SCADA communication protocols such as Modbus TCP, IEC 60870-5-104, DNP3, ETHERCAT, SERCOS III, OPC AU, MQTT and SNMP, to provide a comparative study that allows us to choose the most appropriate protocol for industrial communication, especially in the context of Industry 4.0. Applications/Improvements: We have presented a comparative study to describe the most used SCADA communication protocols. We therefore present the archetecture of each protocol, the quality of service, the context of use, the security, the frame and other information that allow us to choose the most appropriate protocol to apply in the Industry 4.0. Findings: OPC UA is often considered as the next reference for industrial communications, it is a multi-level protocol that includes a security layer to indicate whether future communications will be signed, encrypted or in plain text.