SIMATIC WinCC Open Architecture is a very modular SCADA system. The required functionalities are realized by specific, functional entities created for various tasks. In SIMATIC WinCC Open Architecture these units are called "Managers" - they are also distinct processes in software terms.
WinCC OA Manager |
Task |
---|---|
Event Manager (EV) |
The Event Manager (EV) is the processing center in WinCC OA. This unit provides a constantly updated image of all PowerTags in the memory. Each other functional unit (Manager) that wants to access the data receives it from the process image of the Event Manager and does not have to communicate directly with a controller. Conversely, a command from an operator station is initially set only as a value change in the process image of the Event Manager. The associated driver then forwards it to the corresponding target device (e.g. PLC) automatically. |
Driver Manager (D) |
The lowest level in a WinCC OA System is represented by the process connections, referred to in WinCC OA as drivers (D). These are special programs that handle the communication with the control and field level. Since numerous and very different forms of communication are possible with the PLCs or telecontrol nodes, there are several different drivers that can be selected. In very simple terms, the driver is a unit for converting a particular protocol into the internal communication form of WinCC OA. The driver reads the current states, measurement or counter values from the field and in the opposite direction it forwards commands and setpoints to the lower-level controllers (= the term "control" should be used here and below to represent all possible devices of the basic automation (PLC, DDC, telecontrol system, etc.)). |
Data Manager (DB) |
The Data Manager (DB) represents the link to database. On one hand, it involves the parameterization data of an application that is to be stored in such a database. On the other hand, it involves the historical recording of changes in values or alarms. If a user wishes to query historical data at a later date, then the Data Manager completes this request and not the database itself. |
Control Manager (CTRL) |
WinCC OA has numerous options for implementing your own algorithms and processing. The two most important are the internal language control (CTRL) and the general application programming interface (API). |
User Interface Manager (UI) |
The interface to the user is created by the User Interface Manager (UI). This comprises a graphics editor (GEDI), a database editor (PARA) or the general user interface of the application (Vision module). The User Interface serves to display values, issue commands or track alarms in the alarm list. Trends and reports are also usually part of the UI. From a programming viewpoint, the user interaction in WinCC OA is completely isolated from the background processing – this is merely a view of the data of the current process image or the history. |
A WinCC OA System consists of function-specific units, the managers
For special tasks such as redundancy, management for distributed systems, web server, reporting, simulation, COM etc., further managers are available.
The powerful configuration functions contribute to a reduction of engineering and training overheads and lead to increased flexibility and operational reliability.
Special functions |
Task |
---|---|
Access to external databases |
The database interfaces offer the possibility of access to external databases. |
Application Programming Interface (API) |
The API offers a series of functions that enable WinCC OA to be extended with special managers. A manager means a program that communicates with the system by via a protocol defined by WinCC OA. |
COM (Component Object Model) |
This is a specification for the development of modular software components that can be used by each COM-compatible application. COM components can easily be integrated into such applications and can even be removed from an application during runtime. COM components can be programmed in a host of different languages, even though C++ is usually used for this purpose. The specifications OLE, ActiveX and DirectX are based on the COM technology. |
Control expansion |
Expansion that allows C++ functions to be added to the programming language. |
Panel topology/summation signal |
Generation of panel hierarchies/topologies in existing or new projects and automatic creation of summation signals of the alarm data points that are located in the panels of the topology. |
Redundancy |
The failure safety in a redundant system is implemented by means of hot standby. Hot standby is a hardware-independent solution for high availability. This is a safety concept that consists of two interconnected server systems. Both servers are constantly in operation and are subject to the same functional loading (but only one server is ever active; the second compares the data with the primary unit at runtime). On the failure of one unit, an "on-the-fly changeover" takes place and the previously passive server assumes the leading role. This guarantees access to data or functions at all times. |
SMS |
Allows the sending and receiving of text messages with WinCC OA. |
Voice output |
Offers the user a further option for obtaining interactive information relating to process states. |
Encryption of panels and CTRL scripts/libraries |
Allows your panels or scripts to be encrypted, thereby protecting your knowledge and work. |
Distributed systems |
Permits the coupling of two or more autonomous WinCC OA systems via a network. Each subsystem of a distributed system can be configured either as a single-user or multi-user system, each of which may be redundant or non-redundant. A sub-system in this context means a server on which an Event Manager is running, whereby in case of redundancy both redundantly operating servers are considered as one system. |
The diagram shows a detailed representation of the two computers Server 1 and Server 2. Server 1 is in the management mode (active) and Server 2 is in hot standby mode (passive).
In the case of redundant operation, the UIs of both operator stations are connected to both Event Managers, however only the data of the active system is displayed on both UIs. The Event Manager of the passive system is restricted exclusively to communication with the Event Manager of the active system for comparison of the process data (it sends no data to the connected UIs or it discards messages from the drivers – this can be seen in the figure with the switches on the UIs or on the passive Event Manager).
Distributed systems with WinCC OA
Add-ons |
Task |
---|---|
ETool |
The engineering tool ETool offers significant benefits in engineering in the case of combined WinCC OA and SIMATIC STEP7/PCS7 projects. It provides a user-friendly engineering environment that permits easy, integrated and fast configuration on the basis of the WinCC OA mass parameterization. |
BACnet |
BACnet provides an integrated BACnet-compliant online/offline engineering solution for building automation technology, including object library. Designed for heating, ventilation and air-conditioning, lighting control and safety systems. |
S7 AdvancedLib object library |
The S7 AdvancedLib (AdvS7) is an industry-independent object library that permits the use and visualization of objects from the process control system (e.g. drives, valves, regulators, motors, etc.) in a project with WinCC OA and S7. In addition to the WinCC OA and AdvS7 license, the use of S7 AdvancedLib requires the use of the relevant library on the SIMATIC side. |
Maintenance package |
Includes the following functions: Operating hours counter, operating cycle counter and maintenance log. |
Scheduler |
Permits the creation, parameterization and management of time programs that allow the time and event-driven triggering of specific actions. |
Recipes |
WinCC OA recipes allow setpoints or commands for certain data point elements to be sent simultaneously. Based on "recipe types", which define the quantity of the data point elements concerned, recipes are created that send their values to the data point elements upon activation. |
GIS Viewer |
With the help of this viewer, standardized cards of a geo-information system (GIS) can be fully integrated in WinCC OA. Furthermore, it is possible to display all WinCC OA objects in the cards. |
Excel report |
Powerful report generator directly in Microsoft Excel. Templates can be created easily and directly in Excel. If a report has to be created over a defined period of time, the system accesses the template and automatically completes it with data from the WinCC OA process database. Reports can also be created, printed and saved on a time-controlled basis, without any need for user access. The Excel Report fully supports compression structures (AC - archive compression) of WinCC OA. |
Communication Center |
Stands for modern alarm management/remote alerting and communication using the latest standards and various media. The Communication Center creates synergies by using the various interfaces for remote alerting via the control system. |
Video |
Enables the integration of a video management system in WinCC OA. Through the combination of SCADA and video monitoring in one system, the costs for separate video interfaces and the additional expense of maintenance and operation can be saved, and the period of training for operating personnel can also be reduced. |
HTTP server |
For displaying WinCC OA data via Intranet and Web. |
Authentication via Kerberos |
A WinCC OA System can be exposed to a variety of attacks. An unauthorized WinCC OA System could set up a connection to the distribution manager or hackers could try to manipulate WinCC OA messages. In order to prevent espionage or other attacks, safe authentication was developed. The authentication based on Kerberos enables each WinCC OA component to verify the identity of another component. WinCC OA servers can verify the identity of the clients and clients can verify the identity of the servers. In addition, Kerberos ensures that messages are not modified during their transmission (capture-replay attacks are prevented). Furthermore, it is also possible to send messages in encrypted form. |
AMS (Advanced Maintenance Suite) |
For the effective planning, administration, implementation and monitoring of maintenance work and faults. The processes are evaluated by means of statistics and reports are communicated. |
Disaster Recovery System |
This system expands the simple redundancy to include a second redundant system, to which the system can switch over in the event of a fault (e.g. fire or explosion in the building of the primary system). By means of this additional local redundancy, the highest level of system stability is obtained. |
Pocket Client |
A "thin client" that is also suitable for the remote access via a mobile telephone or a PDA. Access is via a Web browser without any installation and provides a user interface even at those locations whose Internet connections offer very little bandwidth, as only the most essential data is transferred. |
Network topology Video
Disaster Recovery System architecture with WinCC OA