This means that the sensor is not connected to the FilesThruTheAir™ Cloud. Check your network connections first and then make sure that the sensor is within range of the access point or WiFi router. To save battery power, the sensor may be in sleep mode for up to 30 minutes and will then look for a connection again. No data is lost while the sensor is temporarily not connected. Once connection is resumed all data will be synchronised with the FilesThruTheAir™ Cloud.