Alarm device with a support for use in an upright mount

The device (1) has a receiving component (3) that is configured for mounting horizontal runge slats along the side of the cargo area. A sensor antenna section (5) is a capacitive distance sensor is provided on a support (4) that is extended in the longitudinal direction. A sensor control unit (6) is provided with an input/output interface, a capacitive sensor, an alarm output unit and a power supply and is arranged on the support. The sensor control unit is connected with stakes (2) of the truck by electrically conductive contact (7).