This could be happening for a few reasons:

• The device(s) are not operating. The sensors require running current on the machine/panel in order to turn on.
• The Bridge closest to these devices are not close enough to pick up the data readings from the sensors. If the sensor prior to the data gaps is reporting RSSI values of -75 dBm or lower (towards the -100 dBm range), please move the Bridge closer to the sensor(s)
• The Bridge(s) within the sensor(s) proximity are not online/connected to the server. Once the Bridge is back online, as long as the Bridge was powered during the offline period, the data will then be uploaded as historical data and it will fill the gaps you perceive now. 
• The Bridge(s) within the sensor(s) proximity are powered off. 

Please refer to our Troubleshooting Flow Charts below for more details and steps into determining why there are gaps in the data and how to resolve it.