We recently we lost communications with one of our DeltaV Smart switches. In the Smart Switch Command Center the switch was unreachable and showed "RED X" on the device. The event chronicle was also filled with a large number of communication failure alarms.
We found the KBA NK-1600-0387 which details the issue but only offers the resolutions of upgrading to DeltaV ver 14.3 (we currently run 13.3.1) or rebooting the switch prior accumulating 497 days of run time.
We were able to clear the alarm and return the switch to normal operation by erasing the main configuration file and returning the switch to the factory default condition.
Once the switch was returned to default configuration the switch was then visible in the decommissioned switch listing. The switch was then recommissioned as a replacement and returned to normal operation.
Hope this helps someone else if they encounter the same conditions.