Every particle accelerator must have a commanding system that controls and monitors hundreds of various devices and subsystems with sub-microsecond synchronisation. Good architecture and design is the key to building modular, scalable, maintainable, and testable software. This is especially true for large systems such as control systems for accelerators which require high uptime, reliability and scalability for long term operation and future upgrades. Therefore, the accelerator control system (ACS) is an extensive and complex piece of software that must supervise the correct and safe performance of all devices integrated into the machine. The system has to guarantee dependability, stability and performance. It must also be extensively modular and configurable to meet new current and especially future demands.

The COSY (Cooler Synchrotron) is a German particle accelerator and storage ring operated by the Institute of Nuclear Physics (IKP) at Forschungszentrum Jülich that employs beam cooling. The latter helps particles follow more closely their predetermined path. COSY is one of the only accelerators in the medium energy range that uses both stochastic and electron cooling. A few years ago, the need arose to improve the beam control at the Jülich centre, and Cosylab was invited to participate in the project.

In the last decade, control system development for Big Science facilities has become an established engineering discipline and less of a scientific endeavour that it expectedly was, at times, characterised by the "not-invented-here" viewpoint.