The HMI system is provided with a mobile control and monitoring device for automation components of a technical system. It comprises means for contactless data transmission between the mobile control and monitoring device and the automation components, a manual device for triggering or blocking security relevant operations of the technical system and means for locating the mobile control and monitoring device. Evaluation means are provided for managing an active operational area and which activate the automation components for security-relevant operations of the technical system via the mobile control and monitoring device solely when the manual device is released and the locating means detect that the mobile control and monitoring device is located inside the active operational area, the advantage thereof being that manual triggering of security-relevant operations by an operator is the condition upon which they can be activated via the mobile control and monitoring device. If the manual device is placed directly on the housing of the technical system, for example, an operator has to approach in such a way that he/she enters the active operation are in a secure manner.