Campbell Scientific Wireless Sensor Network (CWB100, CWS220, and CWS900) - Manual (Page 67)

Appendix C. Battery Life
In another situation, there may be a sensor in a location that permits a direct
connection to the base, but misses a significant number of data polls.
Changing the sensor’s RF Connection Type setting to Connect Through
Repeater will force it to go through a repeater, and it will not attempt any
direct connection to the base, which may result in fewer missed polls.
When changing the setting to Connect Through Repeater, battery life of the
repeater should be taken into consideration (see Section C.2 above).
C.4 Repair of a Lost Connection
A CWS sensor radio will detect if it has lost the connection to the base, and
initiate a new path discovery automatically. The radio sends out a “beacon”
every 90 minutes, and if two of these are missed in succession, the auto-
discovery process will begin.
If a CWS sensor has not received any data polls from the datalogger for more
than 13 hours, it will initiate the auto-discovery process
C-3