When standards move in, things become simple
Pure Web technology and OPC UA are fundamentally changing how to work with HMI & SCADA systems.
Offshore Systems has developed a flexible software control system platform which enables controlling a multitude of industrial processes locally or remote – from any online device such as a PC, tablet or smart phone
Object orientated software for easy adaption to any relevant control application
Industry expects all HMI and Supervisory Control And Data Acquisition (“SCADA”) systems requirements -from local control, remote maintenance and large control center- be covered by only one solution with a simple one-time engineering process. Monitoring and control should be possible without restriction (as far as the user is permitted) on device, time and place. It should not be necessary to install a special client because a pure Web browser should be sufficient. Additionally, although plants and processes are getting increasingly complex, customers expect faster and easier engineering. In order to meet these challenges through adequate and flexible solutions, modern systems are required to be based on standards. This was the criteria used by Offshore Systems when selecting new HMI/SCADA and PLC/IO technologies, to form the basis for all new control system in 2011.
“native web technology” vs. “web-based”
Although the Web with its browsers offers many advantages for the control and monitoring of equipment and processes, one should be very careful in the nomenclature when selecting a solution: there is a big difference between “native web technology” and “web-based” HMI. Because the HMI/SCADA solution used by Offshore Systems is implemented in native web technology, you need only a web browser without additional software installation or plug-ins such as Java, ActiveX, Flash or Silverlight for a powerful HMI. Of the various platforms, only native web technology requires only a standard web browser and nothing else! Only then will you have the freedom to simply choose any device in order to call up your visualization: on Windows PC, on Android and Apple devices, BlackBerry, industry panels, etc. In order to avoid any nasty surprises when attempting to access the system via the Web, one should always investigate which restrictions apply to a “web-based” solution.
In combination with OPC UA
The HMI/SCADA solution chosen by Offshore Systems has been developed with a consistent implementation of the modern OPC Unified Architecture standard (OPC UA). This is a platform-independent industrial communication protocol which was developed as a successor to the classic OPC. OPC UA is functionally equivalent to OPC Classic yet capable of much more. OPC UA provides the necessary infrastructure for interoperability across the enterprise, from M2M, machine-to-enterprise, and everything in-between. Among others, OPC UA also defines a standardized, vertical, object-oriented process. Simplifying and reducing the engineering work dramatically. Objects for something as simple as a single valve all the way to a complete drying section in a paper machine or a complete floor of a building automation, is defined once and can be arbitrarily instantiated, including display, alarms and history.
OPC UA in end-to-end action
Offshore Systems PLC of choice provides a consistent implementation, based on OPC UA. This means that all object-types and their instances defined in the PLC can be taken over by the HMI/SCADA on a one-to-one basis. These objects from the acquired data structure can now be supplemented with respective alarms, historization, and displays for the visualization of the SCADA system. They are subsequently passed by heredity to the instances. The advantages of a continuous OPC UA-based implementation speak for itself: no data point lists must be handled twice and time-consuming export/import processes or multiple entries belong to the past. In programming, the benefits range from reduced complexity and improved readability to the ease of commissioning and the automatic implementation of changes in all integrated systems. Such a luxury in automation technology engineering is not yet something to be taken for granted.
And, because the HMI/SCADA server also offers its services as an OPC UA server, it can, if required, make all its data available based on standards compatible to external third-party systems (e.g. management systems). The historized data in general can be queried via OPC UA.
Furthermore, OPC UA also offers an integrated security concept based on current international standards. Authentication and encryption are
included in the UA stack. The HMI/SCADA also complies with OPC UA Alarms and Conditions.
The most flexible SCADA
The HMI/SCADA solution offered by Offshore Systems is fully scaleable from small installations with just a few dozen data access points to worldwide multi-plant installations with more than 1.000.000 process variables.
The server can be accessed via LAN or internet for maintenance and modifications while in operation. The pure Web Technology means that any modifications will then automatically be available on all workstations (browsers).
This same technology means that graphical displays are fully scalable.
Refresh rates and response times will surpass all previous experience with web applications and even conventional supervisory control systems.
The scalability of the visualization has proven very effective: with one and the same system, the graphic interface for different control panels can also be implemented as those for the full SCADA control center. Of course it is recommended that meaningful variations of the HMI content are made to fit the available screen size (universal access does not mean that the entire console display should be duplicated on a smartphone for example). With a few easy steps, convergent visualizations can be implemented within a project in order to be meaningfully accessed by different kinds of terminals.
Don´t lose your overview
Standard-based innovations which, within the context of W3C (World Wide Web Consortium), are driven by Internet-giants such as Google and Microsoft, among others, are immediately available. This applies to the incorporation of typical web applications displaying video or CCTV, or maps (GIS), as well as applications powering multi-touch displays for operation and monitoring of industrial equipment and processes. All of the potential applications described here, the uncomplicated handling of firewalls, the fact that a web browser is available on any device and there is no need to install and maintain a client, etc. amounts to plenty of arguments to use pure Web technology for industrial HMIs.