The structure of a SCADA, could be separated between:
- monitoring layer
- data processing layer
- data acquisition layer
Within the supervision layer there can be the elements:
- Supervision client or operator screen.
- Development Client or Development Station.
Within the data processing layer:
- Intercommunication system between the different stations
- Alarm System.
- Reporting system (optional)
- Historization System (optional)
Within the data acquisition layer:
- Communication drivers,
- Elements to communicate with other software such as OPC servers, databases, APIs,…
Generally a SCADA system has these components:
- Controllers or communication drivers: In charge of reading/writing data from physical elements such as PLCs, RTUs, sensors,….
- Central Server or Application Server: Responsible for managing communications between all elements of the SCADA system.
- Historian: Element in charge of storing data in a temporary format to be able to consult them later.
- Supervision client: Interface between people and the SCADA system, to monitor and modify/control system signals in real time.
- Development client: Operator interface to modify SCADA configurations.