An alarm system installed in a region to be monitored, the alarm system comprising: a control panel a graphical interface (122,140,142) for displaying information on a graphical user interface device, a plurality of devices (130, 130') of the alarm system; the devices being in a plurality of locations in the region; each of the devices being identified, via the control panel, by means of a device identifier, with the device identifiers provided on an interactive screen of the graphical user interface device; and wherein the positions of the devices in the region are provided on a plan (110, 110', 510) on the graphical user interface device; wherein the graphical interface (122,140,142) is configured to provide an interactive screen, that screen providing: a display of the devices; the graphical user interface being further configured to enable a user to associate devices with the positions of devices on the plan so as to activate the functionality of each device in the alarm system by allocating a respective unique system address to each respective device using the interactive screen; the graphical user interface device is equipped with a positioning system to identify the geographic position of the mobile graphical user interface device in the region, and; wherein the geographic position of the interface device is displayed on the plan provided on the graphical user interface device; and devices in communication with the control panel of the alarm system are identified from a list of devices which have been detected by the control panel and which is generated and displayed on the graphical user interface device by the interactive screen; and the addresses associated with a respective device are disabled from being associated with any further devices so that each address association is unique, and wherein disabled addresses are shown on the interactive screen and display details of the activated device to which they have been allocated when selected; characterized in that the graphical interface (140. 142) is in radio communication with the control panel wherein the system is configured such that when a user activates a device of the system the position of the graphical interface is taken as the geographical position of the nearest device and the address communicated by that device to the control panel is taken as the address of the device at that geographical position. a control panel a graphical interface (122,140,142) for displaying information on a graphical user interface device, a plurality of devices (130, 130') of the alarm system; the devices being in a plurality of locations in the region; each of the devices being identified, via the control panel, by means of a device identifier, with the device identifiers provided on an interactive screen of the graphical user interface device; and wherein the positions of the devices in the region are provided on a plan (110, 110', 510) on the graphical user interface device; the devices being in a plurality of locations in the region; each of the devices being identified, via the control panel, by means of a device identifier, with the device identifiers provided on an interactive screen of the graphical user interface device; and wherein the positions of the devices in the region are provided on a plan (110, 110', 510) on the graphical user interface device; wherein the graphical interface (122,140,142) is configured to provide an interactive screen, that screen providing: a display of the devices; the graphical user interface being further configured to enable a user to associate devices with the positions of devices on the plan so as to activate the functionality of each device in the alarm system by allocating a respective unique system address to each respective device using the interactive screen; a display of the devices; the graphical user interface being further configured to enable a user to associate devices with the positions of devices on the plan so as to activate the functionality of each device in the alarm system by allocating a respective unique system address to each respective device using the interactive screen; the graphical user interface device is equipped with a positioning system to identify the geographic position of the mobile graphical user interface device in the region, and; wherein the geographic position of the interface device is displayed on the plan provided on the graphical user interface device; and devices in communication with the control panel of the alarm system are identified from a list of devices which have been detected by the control panel and which is generated and displayed on the graphical user interface device by the interactive screen; and the addresses associated with a respective device are disabled from being associated with any further devices so that each address association is unique, and wherein disabled addresses are shown on the interactive screen and display details of the activated device to which they have been allocated when selected; characterized in that the graphical interface (140. 142) is in radio communication with the control panel wherein the system is configured such that when a user activates a device of the system the position of the graphical interface is taken as the geographical position of the nearest device and the address communicated by that device to the control panel is taken as the address of the device at that geographical position.