The operator must always have up-to-date and accurate information about the status of the relevant technology, be it a boiler room, a network of heat exchangers, an individual room control system in an office building or hotel, a PV plant or system of energy resources which make up a virtual power plant.
This information is provided by process visualisation (SCADA). Data are available as tables and schemas offering current values, graphs, alarm and event overviews as well as other information. The application consists of a server, and one or more client stations. The server communicates with process level (PLCs), acquiring online data, and with databases, which provide history data (trends). The server then provides all clients with schemas of technologies and floor plans, tables,etc., which display the data. Clients use web browsers, which simplifies maintenance, licensing, and workstation management.
A graphic work station is able to visualise and collect data not only from Domat-based control systems. As far as larger projects and installations are concerned (where technology is gradually refurbished or expanded based on the investment abilities of the operator), we are able to integrate visualisation with other control systems such as process stations, photovoltaic inverters, cooling equipment, boilers or energy meters. For this purpose, Domat offers a wide range of software components and drivers which allow communication with control systems produced by other manufacturers, either via standard protocols such as Modbus, BACnet, M-Bus or OPC, or via company-specific protocols developed by other manufacturers. This allows us to display values at joint control centres, which we would not otherwise be able to compare or analyse.
Panels with technology schemas, which are the main tools for data presentation, may contain animations, static images, texts, user notes, setters, links to other panels, etc. They are fully customizable. Authorised and trained users may edit the panels, too. Merbon SCADA provides comprehensive management of users and roles.
Alarm management is processed at the process stations or via the SCADA computer – based on the system size, and alarm forwarding and routing requirements. Alarms may be reported/displayed on a screen, via SMS, e-mail, audio message or through other ways. An alarm server is used for larger applications. It collects events from one or more SCADA stations and sends them to users based on predefined criteria, such as priorities, technological unit, equipment placement, time scheduler and preferred communication channel. This allows the system, for example, to report all alarms during working hours on a computer screen, while once the shift is over (based on the time plan or on information from the integrated attendance system) the system sends only critical alarms in form of SMS messages which require confirmation.
Alarms are available in two views: in an active alarms table and in alarm history table, again with sorting and filtering functions. System alarms, such as communication errors, are displayed in a different way from technological alarms. Alarms are subject to a state machine and they can be sorted as unacknowledged, acknowledged, and unreset. The alarm status may influence the controlled technology (e.g. a device may be enabled automatically only after its alarm has been acknowledged and reset). The number of active alarms is displayed in the toolbar.
A technical view is a table with all datapoints in the system. Every datapoint shows its actual value, time of last communication, quality, description, and other parameters which are useful for system diagnostics. Datapoints are sorted in a tree structure with filtering and searching functions. They can be tagged and e.g. sent to a trend to display history.
A very important feature is trend data evaluation. Merbon SCADA offers not only standard line and bar charts, but also modulo and difference charts, and carpet plots. This makes problem analysis easy. Users always have fast overview of all technologies. Trend views can be saved as templates and referenced from e.g. graphic panels. Trend data can be exported as images, tables, or text.
To store trend data (sampled values), own system resources (data files) are used in simpler installations. For more demanding projects, such as storage of tens of thousands of values every minute, Domat uses either its own powerful binary database optimized for value storage obtained from industrial processes, Merbon DB, or InfluxData database. These solutions are capable of handling hundreds of thousands of values per minute. Database has an open interface (API), so data may also be read and used in other systems, such as accounting and ERP software.