SCADA stands for supervisory control and data acquisition and it is used to refer to a control system architecture. This architecture involves the use of computers, network communications, as well as graphical user interfaces (GUI) for supervisory management of processes at a high level. It also uses peripheral devices like discrete PID controllers and programmable logic controllers (PLC) to interface with the machinery or process plant.
There is a scada monitoring system that supervises the operator interfaces and issue of process commands. The scada evolved in response to a need to have a remote-control access, standard automation protocols for local control modules from multiple manufacturers. Today, the scada systems are used control large scale processes over multiple sites situated across large distances. It is a highly popular and largely used industrial control system, but not without concerns. There are scada vulnerabilities that are being talked about that have led to the evolution of scada security solutions.
Scada uses
Scada is used in small to large systems in industrial processes of manufacturing, fabrication, power generation and refineries where continuous, repetitive batch processes need to be run discreetly. It is also used in infrastructure processes like that of water treatment, oil and gas pipelines, electric and wind power generation, transmission and distribution. In large facilities like the airports, ships and space stations, scada is used to monitor as well as control ventilation if the HVAC systems
Scada components
The main elements of a scada system are the supervisory computers or the scada monitoring system that is the computer and the software responsible for the complete control, monitoring and the communication. There are remote terminal units (RTU) that are connected to the supervisory system and interact with the actuators and sensors in the process. Similar to RTUs there are also PLCs connected to the actuators and sensors in the process as well as the supervisory system. The PLCs are more sophisticated than RTUs and are programmed for use as field devices. They are also flexible, economical, versatile and configurable. All these are interconnected with the communication network and also come with a human interface which is the supervisory window.
Architecture
The scada architecture has also evolved over the years from large minicomputers as part of the first-generation architecture to fourth generation architecture using the Internet of things. In between they evolved as distributed (second generation) and networked (third generation) in the path to the fourth generation as it exists now.
Scada security solutions
As mentioned, scada is liable to cyber-attacks just like any other system wherein software, processes and communication networks are involved. The threats are mainly unauthorized access, deliberately induced changes and virus attacks. Few reported large-scale attacks have led to a discussion and awareness on this topic. So, many scada vendors have started using scada security solutions like industrial firewalls that are specialized to VPN solutions, apart from implementing external monitoring systems. These are meant to address the scada vulnerabilities and help fight the threats or ward them off.