Process Visualization from Remote Office to Ex Area

Via Ethernet or Internet, it can take the user interface to a remote office, the machine builder or an external partner. Panel PCs for process visualization serve to indicate and display process data and to operate process machinery and equipment. There are manifold requirements to modern visualization devices. They have to combine easy operation with high availability and high cost-efficiency throughout their life-cycle. ”For the machinery constructor BHS-Sonthofen GmbH, not only the size and the equipment of the suitable panel PC for a machine was decisive but above all the fact that the devices can be integrated easily and with optimum data safety into modern communication structures”, says Franz Lindl from the engineers office for control technology Lindl & Karl in Affing, responsible for the project planning, implementation and set-up of the visualization solution at BHS-Sonthofen. BHS-Sonthofen, a company that is looking back on a long tradition and whose origins are dating back to the German mining and industrial history, is now one of the world’s leading enterprises in the field of mechanical process technology. Their mixing technology is successfully used in the production and processing of concrete and other applications in the construction industry and construction material industry. Their crushing technology is used in the processing of mineral material and in the recycling industry. Filtration technology solutions for continuous processes and batch production cover large fields of application in the chemical and pharmaceutical field and in food and environment technology. All machines and plants distinguish themselves by their high efficiency, their robust design – and by their easy maintenance. To optimize these features even further, BHS looked for a visualization solution for a more complex machine which not only meets the basic requirements but also allows for the modern communication possibilities and can therefore be integrated into remote maintenance systems. The Polaris Panel PC 12.1“ turned out to be the suitable „human-machine interface“. The panel PC series Polaris offers visualization systems for explosive environments. All devices are approved in accordance with ATEX II 2G Ex e q [ib] IIC T4 as well as for the use in dusty Ex areas according to ATEX II 2D tD A21 T80°C IP6X. The panel PCs are designed in protection type “q” (powder filling). The electrical connections are laid via a terminal compartment that meets the requirements of protection type “e” (increased safety) and protection type “i” (intrinsical safety). Available in six sizes Polaris Control is suited for simple applications requiring texts and small graphics. The Panel PCs 5.7", 10.4", 12.1" are suited as human-machine interface for controlling simple machines as well as for operating more complex machines or simple plants. The 15" and 19" panel PCs and remote units are suited for controlling and operating complex plants. BHS-Sonthofen has decided for a device version equipped with a medium-sized graphic display – the Polaris Panel PC 12.1“. It is suited for operating more complex machines or simple plants in mechanical process technology, e.g. mixers, crushers, reactors, centrifuges or ball mills. „It is oper ated by means of function keys, cursor keys, LEDs as well as numerical and alphanumerical input keys“, says Franz Lindl. „Their quantity is such that all applications can be realized in a comfortable and easy way.“ As to the computer technology, Polaris Panel PC 12.1“ also manages to transfer the easy visualization and the easy operation usual in non-explosive environments to explosive environments. The Intel Pentium M processor is noted for its high performance. In addition, the device has sufficient hard disk memory for the customized applications of BHS. The pre-installed Windows XP Professional operating system makes the device suitable for many software packages, e.g. customized software or other commercial standard visualization software. For the on-site operation, BHS uses Bartec’s programming package BMS-Graf-pro. The visualization project is developed in BMSGraf- pro. From there, it is transferred to the panel PC optionally via USB memory stick or via Ethernet by means of FTP protocol. The process coupling takes place via Profibus DP. In addition, well-established SPS protocols, e.g. MPI, MODBUS or RTU, are supported by the visualization system. Within the standard solution, Polaris is a singletask application. “BHS wanted to take one more step forward and realize the remote maintenance of the machine control and the operating unit in explosive environments from the remote office to the Internet“, says Franz Lindl. The application of Windows XP Professional and of the visualization software BMS-Graf-pro-Runtime permits on-site operation of the Panel PC. The use of the remote software VNC permits the access to the device via Ethernet. After the connection has been established, the log-in screen of the device appears on the user’s screen – making a remote intervention into the control possible. To provide optimum data safety, a separate server is interposed. This server communicates both with the panel PC and with the PC in the remote office, while the transfer of the visualization data takes place separately via a separate Ethernet/Internet connection. „In pre-defined time intervals, the server assigns new IP addresses both to the Panel PC and the PC in the remote office“, says Franz Lindl. „An external computer trying to enter into the communication will receive the message “address unknown“, i.e. it falls out of the running communication and cannot enter again.“ With the Polaris Panel PC 12.1“, the remote maintenance application for BHS-Sonthofen was implemented successfully. The XP Runtime developed for this purpose is considerably faster than the version with DOS operating system. After the data transfer via Ethernet has been completed, XP Runtime is started automatically. In the configuration with Windows XP Professional and Remote via Ethernet, the Polaris visualization systems offer many new application possibilities in explosive environments. By Hubert Dornberger.