Citect SCADA Collector Historian Redundancy

Since one collector can push data to only one historian, you would need to configure 2 collectors. These could be on the 2 redundant servers, or clients.
To ensure you push the same alarm and trend timestamped data to the historian, set the alarm and trend server priorities in Citect.ini. This way, each collector would communicate to the same alarm/trend server, hence you would get the same timestamped data in the historians.

P.S.-I an testing this in this week, I will update if I face any issues.

Since one collector can push data to only one historian, you would need to configure 2 collectors. These could be on the 2 redundant servers, or clients.
To ensure you push the same alarm and trend timestamped data to the historian, set the alarm and trend server priorities in Citect.ini. This way, each collector would communicate to the same alarm/trend server, hence you would get the same timestamped data in the historians.

P.S.-I an testing this in this week, I will update if I face any issues.