Last week this procedure saved our time a lot.
to repair communications issue on Proventia M and Site Protector, the corrupted rsPostSensorEventQueue.adf file must be restored.
follow the steps
1.Login as root.
2.Stop the issDaemon service: service issDaemon stop.
3.Rename the old queue file: mv /cache/spool/crm/rsPostSensorEventQueue.ADF /cache/spool/crm/rsPostSensorEventQueue.old
4.Start the issDaemon service: service issDaemon start