1 year ago

MDA Technologies 3/2015

MDA Technologies 3/2015

The revolution in

The revolution in PC-based control Alexander Samuel Grimm Thanks to its openness, PC-based automation has demonstrated its value in the manufacture of special-purpose machines. Until now, however, the controller was dependent on the PC operating system, which resulted in disadvantages related to availability. This drawback can only be eliminated through a completely new architecture. 18 MDA Technologies 3/2015

MEASUREMENT AND CONTROL About Company name: Siemens AG Headquarters: Nuremberg, Germany Employees: approx. 357,000 Products: Integrated hardware, software and technology-based services for manufacturing companies worldwide Author: Alexander Samuel Grimm, Marketing Manager PC-based Automation, Siemens AG, Nuremberg, Germany Suppliers of PC-based controllers rely almost exclusively on Windows operating systems in order to guarantee compatibility with third-party software. Until now, a real-time core was embedded within Windows in order to implement a software controller with real-time capability. The control functionality was thus only available if the operating system was running properly. A Windows crash or restart therefore inevitably caused a standstill of the controller and thus the entire machine or plant as well. In production use, this entails considerable costs. If the controller controls processes involving heating or adhesives, shutting down and restarting the controller is extremely time-consuming. The adhesives used cannot be allowed to harden; at the same time, heating processes usually have to be reset and restarted in several stages. Possible factors causing the failure of an operating system could be malicious software, crashes caused by overloading, or an intentional system restart when installing new software. Increased system availability The demand for greater availability of a software controller cannot be met within the Windows environment. Instead, the control functionality must be isolated as far as possible from the operating system of the PC. In response to this, Siemens has developed a new, and currently unique, software controller for Simatic industrial PCs: the S7-1500. This offers the functionality of an S7-1500 for PC systems, but runs parallel to rather than within Windows. A “bare metal hypervisor” allocates the PC resources such as interfaces, processor cores, or memory directly to Windows or exclusively to the software controller. This means that any Windows crash or restart has no effect whatsoever on the execution of the control program. The new architecture of the software controller offers a host of possibilities. Installation of new Windows programs or updates would normally necessitate a restart. However, this can now be done during operation, as the control function is fully assured during the restart. This independence from Windows is also reflected in the startup behavior: Previously, Windows always had to be fully booted up before the software controller could be started. The new architecture permits a parallel booting process, so that the software controller is ready for operation while Windows is still loading. Depending on the PC hardware used, the startup procedure for the software controller is up to five times quicker than the previous architecture. Tailored to special machine construction PC-based automation is becoming increasingly important, particularly in special machine manufacturing. One reason for this is the possibility of implementing compact systems, as several applications can run on one device. This means that, in addition to the control functionality, the Windows side can also be used for database applications, visualization tasks, or as a gateway to higher-level manufacturing execution systems. On the other hand, complex algorithms in a high-level language can be integrated directly into the control program. The new S7-1500 software controller is available both for Simatic industrial PCs and for the new Simatic ET 200SP Open Controller. This PC-based CPU is a powerful PC platform with the modular expandability of the ET 200SP I/O system. The range of modules extends from digital and analog input, output modules to counters and energy measuring modules, all the way to time-controlled modules for implementation of the shortest response times. In terms of the Simatic industrial PCs, a wide range of hardware platforms is available. This extends from fanless box and panel PCs to high-performance computers in 19” rack formats. These also enable the parallel operation of controller and computing-intensive image processing tasks, such as those often demanded in quality control applications. The parallel operation of several applications on one device also makes it easier for them to communicate with one another. MDA Technologies 3/2015 19


WORLD OF INDUSTRIES - Industrial Automation 1/2017
WORLD OF INDUSTRIES - Industrial Automation 2/2017
WORLD OF INDUSTRIES - Industrial Automation 3/2017
WORLD OF INDUSTRIES - Industrial Automation 4/2017
WORLD OF INDUSTRIES - Industrial Automation 5/2017