One system for efficient plant operation
Optimized Human Process Interface: The SIMATIC PCS 7 Operator System
Process plants are becoming more complex and the range of tasks performed by plant operators is broadening. In order to optimally support the operating personnel, it is important that relevant process information is always available. All plant statuses and operating parameters must be displayed clearly, simply and concisely in the control room. The SIMATIC PCS 7 operator system meets all requirements for convenient, reliable and safe process control. The architecture is very variable and ranges from single-user to multi-user systems.
In regular plant operation, the operator system serves to clearly display all processes and to support manual operator interventions comfortably and reliably. In critical process situations, the system is characterized by rapid fault diagnosis, reliable decision-making and effective implementation of measures. Among other things, the Alarm Help Procedure serves this purpose: It allows the individual input of different help texts, such as maximum reaction time and priority, description of possible reasons for an alarm, recommendations for desired measures as well as effects on the process. The alarm help text proactively helps to avoid errors and to minimize downtimes.
In addition to the support provided by multi-screen technology, a short screen selection time ensures greater ease of operation and increased attention of the plant operators. With it, even detailed and large operating screens with many variables can be set up much faster. This leads to more fluid work and contributes to more safety.
A highly effective alarm management also contributes to the relief of the operating personnel. Functions such as the visual and acoustic suppression of messages that are not relevant depending on the operating status or the suppression of the alarms of a sensor/actuator during commissioning or in the event of malfunction.
All operator stations are based on modern SIMATIC PCS 7 Industrial Workstations, which are optimized for use as OS Single Station, OS Client or OS Server and can be used in both office and industrial environments. The operator system can be designed as a single-user or multi-user system.
With a single-station system (OS Single Station), the entire operating and monitoring functionality for a project (plant/subplant) is combined on one station. For small to medium-sized projects, a server-free so-called "flat" system configuration with OS single-station stations can be implemented. Two stations form a redundant OS Single Station pair, which can be extended with up to six OS Single Station stations as reference stations.
A multi-user system consists of operator stations (OS clients) which are supplied with data (project data, process values, archives, alarms and messages) from one or more OS servers via a terminal bus. SIMATIC PCS 7 offers a client/server configuration for medium-sized plants or large-scale projects with more than 30 operator stations. The system bus and terminal bus can be set up separately and redundantly with parallel redundancy protocol. This increases the availability and robustness of process plants.
The Operator System already integrates a high-performance archive system based on Microsoft SQL Server with circulating archives for the short-term archiving of process values (typically 1 to 4 weeks) and messages (typically 2 months).
An integral component of the OS software is a high-performance archiving system for short-term archiving. It is used to record process values and messages/events in circulation archives. Process data, reports and batch data can be stored time- or event-controlled from the short-term archive for permanent archiving in a central long-term archive. The central archive server (Process Historian) can be designed redundantly. This increases the availability of long-term data.
While the reporting system is intended to document the project created in the course of project planning, the protocol system serves to clearly print out the data recorded during operation. Various predefined protocol types are available for this purpose:
- Message sequence log
- Message and archive log
- Measured value log
- Operation log
- System message log
- User log
The message system integrated in the operator system records process messages and local events, stores them in message archives and displays them via configurable alarm lists. By filtering, selecting or sorting the display according to the contents of individual message blocks, e.g. chronologically according to message priority or fault location, the operator can adjust the alarm lists individually during runtime.
The operator can display archived process values in relation to time or in relation to another value (function window). Predefined TrendControls can be individually adapted during runtime operation. These settings are saved globally or user-specifically.
SIMATIC PCS 7 Web Server offers the option of operating and monitoring a system via Intranet/Internet. The system can be managed via Web Client in the same way as via an OS Client. The operations performed on the Web Client are recorded in the OS operating protocol. The process images are displayed on the PCS 7 Web Clients via the web browser. For this purpose, the Web clients access the project data provided by the Web server via Intranet/Internet.
SIMATIC PCS 7 offers the visualization of SFC via Web. SFC (Sequential Function Chart) is a sequence control that is used for the control flow-oriented control of processes. The SFC visualization of the operator system enables the sequence controls configured with the SFC editor to be displayed and operated in the same way as on the engineering system. No additional project planning effort is required for this. SFC block icons, SFC faceplates and SFC controls can be operated via Web Clients. All information displayed in the screen module is also available on the Web Client. Trends can also be configured on the Web Client. In process mode, process values can be displayed, compiled, stored and retrieved in curve form using the "Call up/compile trend groups" functionality. Trend groups created online are stored in the Web Server and are thus available on the OS Client and all other Web Clients.
Network disturbances or poor network connections can affect the speed of the Web Client. Therefore, in addition to remote access via the web option, remote control of a PCS 7 system with local PC systems (terminal client) using Remote Desktop Protocol (RDP) is possible. RDP allows the mapping and operation of OS clients on a simple terminal device, such as a thin, PDA or RDP client with Microsoft and RDP protocol installation. Web server and terminal server can be installed and operated on one computer. The web clients installed in the terminal server allow access to the web server applications. Terminal servers run the Web clients that allow access to multiple applications running on a Web server. Terminal sessions for the thin clients are opened on the terminal server. Thanks to common Microsoft IT security installations, remote access via RDP is very secure. The terminal devices are maintenance-friendly and do not have to be upgraded permanently – the maintenance effort is shifted to the central system. Central changes on the terminal server are then available on every terminal device.
Via WinCC/WebUX, the device-independent integration of smartphones, tablets, PCs and other mobile devices into the operation and monitoring of SIMATIC PCS 7 is simple and safe. WinCC/WebUX works as a browser application, i.e. no software installation is required on the clients, mobile devices only have to support HTML5 capable browsers. All communication is secure via https and SSL certificates. Via the user administration, user-specific access authorizations are set up both for pure observation and for operation without time-consuming additional configuration. WinCC/WebUX turns mobile terminals into operating and monitoring stations: The display of alarms and curves is possible as well as the display of important information (KPIs) as values or trends. Users can now implement more flexible operating concepts and monitor or control processes via the Internet or Intranet.
