With the development of modern manufacturing methods, production equipment is evolving toward greater flexibility, multifunctionality, and network connectivity. This trend has created new demands for CNC controllers—requiring that their functions be reconfigurable, modifiable, expandable, and even regenerable. Consequently, there is an increasing need for “openness” in control systems. Manufacturers of controllers are seeking open CNC systems that offer higher performance-to-cost ratios and enhanced product competitiveness. Moreover, the integration of manufacturing information and the decentralization of production systems are also driving the move toward open architectures. Rapid advancements in internet technology have further laid the material foundation for achieving this openness.
Research into Open Architecture CNC (Computer Numerical Control) systems began in 1987 with the U.S. government-sponsored Next Generation Controller (NGC) project. Its goal was to establish a Specification for an Open System Architecture Standard (SOSAS), built upon the principles of interoperability and hierarchical software modules. In 1994, three major American automotive companies—Chrysler Corporation, Ford Motor Company, and General Motors Powertrain Group—initiated the OMAC (Open Modular Architecture Controllers) project. The objectives of OMAC included reducing controller investment and maintenance costs, improving machine tool utilization, enabling plug-and-play software/hardware modules, and supporting efficient controller reconfiguration. This approach aimed to shorten product development cycles, accelerate technology upgrades, and better adapt to evolving market demands.
In Europe, the OSACA (Open System Architecture for Control within Automation Systems) project was launched in 1992 under the coordination of the ISW Institute at the University of Stuttgart, Germany. With a budget of €11.4 million and participation from institutions, universities, and manufacturers across 11 countries—including Germany, Italy, France, Switzerland, the UK, and Spain—the project concluded in 1996. The OSACA model envisioned a system composed of freely combinable modules operating on a standardized platform, representing one of the most ideal models among open controller architecture initiatives. Today, major European CNC manufacturers such as SIEMENS, BOSCH, NUM, and FAGOR are actively developing open CNC systems compliant with OSACA standards.
In Japan, the OSE Association was formed in 1995 by machine tool manufacturers and companies in the information and electronics sectors to conduct research under the OSEC (Open System Environment for Controller Architecture) initiative. The project was executed in two phases. The first phase, OSEC-I Design, focused on exploring the significance and direction of open controllers, during which the FADL language was proposed—a neutral language supported by multiple companies, intended to serve as an interface between users and controllers. The second phase, OSEC-II Design, aimed to develop a fully functional, installable architecture. In OSEC-II, the FADL language evolved into OSEL, a new NC language with reusable features that packages manufacturing expertise accumulated by end users and machine builders into software modules.
The core task of these research initiatives is to establish standardized architectural specifications for open CNC systems. With such standards in place, developers can create interoperable and interchangeable functional modules. Through standardized interfaces, modules provided by different manufacturers can be assembled into customized CNC systems that meet specific application requirements.
