E-Stop buttons (emergency stop push buttons) are emergency stop devices. E-Stop buttons act as the first line of defense when ensuring the safety of workers and protecting a machines process. When actuated Emergency Stops must ensure hazardous motion is stopped effectively and, in a manner, to reduce or eliminate an exposure to hazardous situations. Used in combination with an elobau safety controller the safety circuit can react with the machines demands and provide the required performance level required up to Category 4 / PLe (ISO13849-1). With optional failsafe monitoring contact, it can be ensured that the Emergency stop function is reliable and meets the demands of the application.