An alarm device monitoring and control tool (1, 40) comprising a processor (2, 40), and a radiation transceiver adapted to locally communicate with alarm devices within a group, wherein the processor (2, 40) is adapted to: generate and transmit test instructions for the devices; and to receive and process historical event data stored by the devices and transmitted by the devices in response to said instructions, wherein said historical event data includes: RF signal strength data indicating RF signal strength between devices, including a Received Signal Strength Indicator value, repeat level data measured by the alarm devices and indicating a number of hops for communication between a device and another device, and relative time indicators for events, each said time indicator being according to a device's relative clock and including a count value from a last reset; process said historical event data to test reliability of wireless communication paths between the devices by: processing said repeat level data to generate an indication as to whether there is a direct connection between devices or how many hops a device must go through to have a connection with each other device, and process said RF signal strength data including a Received Signal Strength Indicator value, to determine whether or not a connection between any two devices is sufficient, and if a device has more than one path to another device; characterised in that the processor (2,40) is adapted to dynamically convert said relative time indicators in the historical event data to real time stamps; and generate an alert if said historical event data indicates a pattern of activity which may lead to failure of a device or to an alarm event, wherein the tool is adapted to act as an interference meter by measuring electrical noise in a reception band or bands being used by the alarm devices, and wherein the tool is adapted to generate and display in graphical or numerical form data regarding a level of separation required between an interference source and alarm devices to ensure correct operation of said alarm devices. RF signal strength data indicating RF signal strength between devices, including a Received Signal Strength Indicator value, repeat level data measured by the alarm devices and indicating a number of hops for communication between a device and another device, and relative time indicators for events, each said time indicator being according to a device's relative clock and including a count value from a last reset; process said historical event data to test reliability of wireless communication paths between the devices by: processing said repeat level data to generate an indication as to whether there is a direct connection between devices or how many hops a device must go through to have a connection with each other device, and process said RF signal strength data including a Received Signal Strength Indicator value, to determine whether or not a connection between any two devices is sufficient, and if a device has more than one path to another processing said repeat level data to generate an indication as to whether there is a direct connection between devices or how many hops a device must go through to have a connection with each other device, and process said RF signal strength data including a Received Signal Strength Indicator value, to determine whether or not a connection between any two devices is sufficient, and if a device has more than one path to another device; characterised in that the processor (2,40) is adapted to dynamically convert said relative time indicators in the historical event data to real time stamps; and generate an alert if said historical event data indicates a pattern of activity which may lead to failure of a device or to an alarm event, wherein the tool is adapted to act as an interference meter by measuring electrical noise in a reception band or bands being used by the alarm devices, and wherein the tool is adapted to generate and display in graphical or numerical form data regarding a level of separation required between an interference source and alarm devices to ensure correct operation of said alarm devices.