800xA with 400Connect alarm issues
1. Event Collector service
Does your service configuration contain an event collector service group and service provider(s) connecting the MB300 OPC AE server in the "generic connectivity" - if not you must configure this.
2. Lost and Found
Have you checked if the alarm(s) have arrived in the Lost & Found folder?
The L&F folder is populated for each alarm that does not match up with an object at the very first time an alarm arrives from the OPC AE server.
If you find your alarms there; consider running another MB300 Upload, then delete the child objects below L&F (keeping the L&F parent itself intact); then restart the Event Collector service group for AC400 Connect and try again.
Some L&F is "unavoidable" if online programming is used (who can build a whole factory to completion in ECONFIG mode?) - cleaning of L&F is hence "normal business" with AC400 Connect.
Alarms from objects in L&F will NOT arrive in alarm or event lists making use of Objects and Descendants filtering (unless the L&F object happens to be one of the children).
3. User defined event texts
"loaded the Rtab with the site config" = are you using user defined event texts?
A standard MB300 AI uses LIM_TR 3 for events and LIM_TR 4 for alarm + events.
E.g. if an MB300 AI object uses LIM_TR with higher value than 25 it is considered using a user defined event text; then the RTA board's Event Treat database must be populated with a matching event text, or else the alarm risk being supressed.
Lack of event treat elements usually triggers DCCA200 system messages at RTA board level when controller is sending alarm or events.