For the purpose of visual and affordable perception of the OpenSCADA system architecture in general the Figure 1 shows the static class diagram of OpenSCADA on the universal modeling language (UML). Based on the chart it is clear that the OpenSCADA system contains modular subsystems: "Archives", "Databases", "Transports", "Transport protocols", "User interfaces", "Data acquisition" and "Special", as well as subsystems: "Safety" and "Module's management". The chart graphically presents the relationship between modular subsystems and modules.