When you look at your data and you see that a handful of devices paired to a single CCU aren't communicating for an extended period, there are only two main reasons this could be the case.
1. The devices lost power. The first step is to verify at the devices that their screens are poweres and they have sufficient power.
2. The Devices are out of RF range. If the same devices have always had issues it is likely that they are having problems communicating which is typically due to range. There are other reasons RF may begin having issues as well.
- Range - the distance is simply too far. 900Mhz Mesh Range
- Interference - There is something else broadcasting on the same frequency. In this case if you lose RF communication intermittently or all at once suddenly. Check first that no new wireless devices were installed in the building.
- Broken Antenna on the device. Check that the antenna did not get broken during construction or any service event.