Ian Gilvarry is worldwide industrial automation marketing manager within the Intel Embedded and Communications Group. He can be contacted at [email protected] Courtesy Intel. All rights reserved.
Traditional industrial automation control has been implemented using the programmable logic controller (PLC), a programmable microprocessor-based device used to control assembly lines and machinery on the shop floor as well as many other types of mechanical, electrical, and electronic equipment in a plant. Typically programmed in an IEC 61131 programming language, a PLC was designed for real-time use in rugged, industrial environments. Connected to sensors and actuators, PLCs were categorized by the number and type of I/O ports they provided and by their I/O scan rate.
For over two decades PLCs were engineered using proprietary architectures. These PLCs were based on dedicated hardware platforms, with real-time operating systems (RTOS), and functions strictly limited to the actions to be performed. With such PLCs, when you selected a particular vendor and PLC family you were locked into the corresponding boards and functions that were available to that particular line. While this approach offers easy-to-integrate hardware, high quality components, and knowledgeable support, it also is closed to unusual implementations or deviations from standard configurations.
PLCs have served well as individual islands of manufacturing control. However, digital factory automation has evolved into complex, interconnected manufacturing cells. Process control data flows upwards from the cell into the MRP system, as dynamically reconfigurable process steps flow downwards. "Just in Time" (JIT) product distribution and an increasing number of offered products drive companies towards reconfigurable manufacturing. Connecting the work cells into the plant's MRP system requires new communication interfaces and also creates a demand for statistical information and additional data acquisition at the work cell. Work cells are also increasing in sensor count and complexity. Often these newer sensors are difficult to interface with traditional PLC hardware. The communications interface, the statistical functions, the data acquisition functions, and the new sensors are often difficult to add to the traditional PLC.
Towards Embedded Processors for PC-Based Industrial Automation
In recent years industrial control systems have been transitioning more towards standardized, general-purpose platforms based on the adoption of PC technology. One of the fundamental drivers for this has been the desire by end users to merge their information technology and automation engineering systems into one complete end-to-end platform. The push of information technology into automation is happening at the field Level where sensors and actuators are more and more intelligent, and also at the control level, where embedded PC technology is being used to replace the traditional PLC.
As well as convergence of information systems and automation engineering, the deployment of web-service based architectures and the proliferation of industrial Ethernet are additional factors that are influencing end users and original equipment manufacturers (OEMs) to migrate industrial control systems to PC-based architectures.
Special software packages for embedded PC platforms implement the functions that traditionally were implemented in separated dedicated hardware. Advantages here are many including:
- No need of dedicated hardware
- Integration of different functions in a single machine (HMI and PLC run in a single embedded PC)
- Ease of interfacing basic control functions with high level functions
- Native remote communication using Ethernet or the Internet
Today a digital factory system includes a network of intelligent field devices and one or more dedicated devices for running the control tasks that are called controllers. Additional devices may be used for human machine interface (HMI), remote communication, data storage, advanced control, and other tasks.
Traditionally the terms "low power" and "ultra low power" when used in relation to Intel processor platforms have been at odds with the definitions used in embedded designs. Typically there was an order of magnitude difference between the two, with Intel's lowest power platform, of the order of 10 W, compared to a typical 1-W envelope for a low power embedded platform. This challenge was a barrier for the adoption of Intel architecture into the fanless, completely sealed designs commonly required in the typical harsh working environment of industrial control. Designers were faced with the dilemma of designing expensive thermal solutions to be able to adopt the benefits of PC architectures into the industrial control arena.
Realizing the Threshold for Fanless Industrial Control Designs
The Intel Atom processors are the first of a new generation of processors over the coming years from Intel that will focus on addressing demand for performance in the tight constraints and harsh operating environments typically associated with industrial automation. Designs will benefit from being designed with the open architectures associated with PC technology but at the same time meet the demands of miniaturization associated with small form factors platforms, and cost-effectively meet the demand for more distributed intelligence in the factory.
The Intel Atom processor Z5xx series brings the Intel architecture to small form factor, thermally constrained, and fanless embedded applications. Implemented in 45 nm technology, these power-optimized processors provide robust performance-per-watt in an ultra-small 13x14 mm package.
These processors are validated with the Intel System Controller Hub US15W (Intel SCH US15W), which integrates a graphics memory controller hub and an I/O controller hub into one small 22x22 mm package. This low-power platform has a combined thermal design power under 5 W, and average power consumption typically less than 2 W.