Command devices are of great importance for the man-machine interface in the area of industrial applications. For example, they are mounted in switch-boards, control panels, two-hand control panels, in lift manufacture and on materials-handling plants, including conveyors. Manual actuation of the devices starts operating sequences and functional processes or serves to bring these to an end.
Emergency stop command devices are generally connected in the safety circuit of a machine or plant and are of particular importance in terms of the control system for these. In case of a fault or accident, the secure function and quick accessibllity of Emergency Stop command devices can be crucial for saving life, limiting the degree of injury to personnel or the extent of damage to a machine.
New requirements are placed on the mode of operation of these command devices by the new harmonised European Standard EN 418 regarding functional aspects and recommendations for the arrangement of Emergency Stop equipment.
