A sensor is offline, why is it?

If a sensor is shown as offline in the app, it might be for two reasons:

1.The sensor or the sirens are located outside of the range of base (max 50 m inside buildings). In this case the LED flashes on the sensor.
2.The sensor battery is flat (does not apply to mains-powered sirens). If you get a message in the app that the battery is almost flat, this is most likely the reason. By clicking on the filter function in the event list you can find this message quickly. In this case the LED on the sensor does not flash.