Users continue to associate PLCs with attributes such as instant on, high mean-time–between-failure (MTBF) and high mean-time-to-repair (MTTR). A reputation for reliability, performance, repeatability and predictability continues to drive demand for simple, rugged systems capable of withstanding harsh industrial environments.
The PLC platform has evolved by incorporating open standard interfaces, multidomain functionality, distributed modular architectures and modern software capabilities integrated as turnkey automation solutions. The label “PLC” simply understates the capability of current automation systems. As a new generation comes to market, the more apt notion of Programmable Automation Controller (PAC) will displace its predecessor. PACs augment the function and role of the traditional PLC by defining new capabilities.
Flexible and configurable, PACs can be customized and optimized to meet the application needs for both machine and plant automation systems. All parts of the PAC are designed to maximize software and hardware integration. A single programming environment and engineering tool provide transparent access for all parameters and functions within the entire system. A single platform can combine PLC, soft logic, remote input/output (I/O), motion control, drives, PID control, user guidance, visualization and data handling. The use of Ethernet TCP/IP, Internet and IT standards maximize data integration throughout the enterprise.
The emergence of PACs will continue the shift in emphasis toward communication standards and software integration. Users will become more focused on total system performance than on hardware selection. PACs will address user concerns about how better to monitor and control real-world devices. This keeps the suppliers of PACs thinking more about system performance and less about market differentiators at the component level.
In a collaborative manufacturing environment, the multi-functional capabilities of a PAC enable access and exchange of production process information, and connect factory-floor operations to enterprise-level systems. Where traditional PLC products require proprietary programming languages, a PAC can be commanded using IT standards, such as SQL queries, and open data transfer technology, such as OLE for process control (OPC) and extensible markup language (XML). This provides faster updates of actual, not copied, data, and consumes minimal bandwidth because the enterprise system does not have to poll the controllers. Rather, the PACs send data based on events.
There is an increased dependency on suppliers for services ranging from consulting to full turnkey projects. Users are refocusing their energies on core competencies and relegating many integration functions to their automation providers. This creates a much higher need for service and support offerings that will complement and utilize the multifunction capabilities of PACs. An example of this could be Web-based monitoring and maintenance through a PAC for multiaxis motion control, position control and cam position. Operators can access the supplier’s Web site, allowing technicians to diagnose and troubleshoot problems directly from the plant floor.
Programmable Automation Controllers, or PACs, will play a major role in plant and factory automation by adhering to open industry standards and providing multidiscipline programming and functionality. All parts of a PAC system must be designed to offer end users one programming and engineering tool.