Control virtualization in an era of software-defined machines
In a control system context, applications must behave in a safe, secure, predictable, and reliable way, while increasing flexibility. The automation industries are adopting multi-core architectures to get the size, weight, volume, and power consumption benefits being driven by consumer electronics. However, the use of multi-core, parallel processing technologies is only possible if software can exploit the cores in an efficient manner. The trend toward multi-core computing is of significant importance to embedded and control system applications, especially with recent advances in virtualization technology enabling cost-effective exploitation of the architectures.
Future of control systems
Integrating virtualization and remote, networked I/O into technology offerings provides better resource use, smaller footprint, lower power usage, and long-term migration flexibility in control architectures. Virtualization partitions the hardware to provide flexibility and simultaneously run critical and noncritical applications (such as HMI and real-time control) on the same hardware. For example, applications requiring a smaller footprint now can combine multiple physical computers in a virtualized architecture to save physical space and associated costs. Separating the I/O from the core controllers via today’s high-speed and reliable networks allows the controllers to be upgraded easily while preserving the I/O infrastructure and allows the I/O to be distributed closer to the point of use. This reduces wiring and installation costs while connecting different I/O types in the same cabinet or even using wireless connectivity. For harsh environments, the possibility of limiting those certifications to the I/O device also reduces costs.
Flexibility in control systems helps with keeping up with rapidly changing requirements and advances in technology. Industrial Internet control systems are designed with this in mind. For example, some open platform controllers are built from industrial-grade components without fans, for reliability in harsh environments. Future performance upgrades can be managed with the rugged and modular COM Express architecture [COM is computer on module; COM Express is a PICMG standard], maintaining the same casing and footprint.
Consolidation of control, HMI, and data management
A simple and logical application of a hypervisor-enabled control system is the integration of control with supervisory level functions. [A hypervisor is software or hardware that runs virtual machines.] System integrators, original equipment manufacturers (OEMs), and end users have developed specialized human-machine interface (HMI) applications. In this use case, the control system integrates the control, HMI, and historian into the same physical hardware, delivering a tightly integrated architecture.
In traditional architectures, the programmable logic controller (PLC) runs the control logic, while one or more commercial PCs are used for the HMI and historian functions. Separating control and HMI has presented challenges to PLC engineers who struggle to get information from the PLC into the HMI application. In this consolidated architecture, the HMI has direct access to the PLC, and embedded interoperability standards, such as OPC-UA, make communication between the PLC and HMI easier and more comprehensive than before.
Additionally, a modular architecture provides for a more robust product lifecycle and migration plan. An obvious benefit of a hypervisor-enabled control system in this application is the consolidation of the PLC and PC for reduced footprint, energy usage, and cabling. A small footprint is especially critical with remotely distributed assets found in the marine, power generation, and oil and gas industries.
The combined PLC, HMI, and historian configuration is simple enough to allow customers to take on tasks such as setup, configuration and troubleshooting because they have direct access to the controller, streamlined architecture, an open solution, use of IEC-compliant language, and interoperability standards. This also allows flexible configurations for operating systems, powerful control with large feature sets, as well as connection to intelligent platforms and third-party devices. The consolidated application provides data access at the asset or operational level that might previously have been inaccessible or cost-prohibitive.
Lean automation system architectures
The key concept of software-defined machines is the decoupling of machine software from the hardware. This next generation of control systems built for the industrial Internet will deliver fully integrated systems for I/O, control, and software applications that will facilitate the progression through the industrial Internet network. These control systems will incorporate technologies such as hardware partitioning and network as the backplane for increased flexibility. Lean automation system architectures will be favored as the industrial Internet matures, since they provide the infrastructure to evolve and grow in the future.
– Rich Carpenter is the chief technology strategist at GE Intelligent Platforms Software. Edited by Eric R. Eissler, editor-in-chief, Oil & Gas Engineering, firstname.lastname@example.org.
- Modular architecture provides for a more robust product lifecycle and migration plan.
- Lean automation system architectures will be favored in the future.
- The trend toward multi-core computing is important for control system applications.
See an IoT webcast at www.controleng.com/webcasts and the related virtualization articles linked below