DEVICE OF A SENSOR UNIT FOR A SURVEILLANCE SYSTEM

摘要

A device is described of a sensor unit for a surveillance and/or a message system, comprising of a body that can move on a foundation which includes teh sensor unit which comprises a transmitter and receiver units for transmission of signals between sensor and a centre, where the body is arranged to take up arbitrary positions on a foundation. The device is characterised in that the body is mobile ball in which the sensor unit with transmitter and receiver is fitted, with the ball comprising a drive element to rotate the ball, and in addition means to control the ball's drive element and the sensor unit. Also described is an alarm system as well as an application of the device.