BrightSign Object Reference Manual (FW 5.1) - Manual (Page 152)

144
Writes do not always take effect immediately to prevent the system from exceeding the maximum number of writes on the
onboard persistent storage. At most, 60 seconds after a write to the registry, the newly written data will be automatically
written out to persistent storage. If, for some reason, the change must be written immediately, then one of the flush
functions should be called. Changes are automatically written prior to exiting the application.