This European Standard is drafted on the basis of essential system functions and components which are provided on all electrically controlled hold-open systems and which comprise hold-open device(s), a control unit, a power supply unit, and fire detector(s) (see Figure 1). Options with requirements for additional system functions and components can also be provided, such as remote indicating devices, interconnecting cables, door position sensors, interfaces with other systems, manual controls and a stand-by power supply (see Figure 2).