An online upgrade takes advantage of Citect SCADA's native server redundancy to minimize or avoid loss of data or downtime on your production system, allowing for one server to take ownership while the other is being upgraded. An online upgrade is the only way to avoid loss of data where you perform an upgrade in parallel. This is the process in which the two SCADA systems (the old version and the newer one) are running side-by-side. The old version is decommissioned after the new version has been fully tested and validated.
Similar to the offline upgrade, you will need to follow the upgrade path, and repeat the process as many times as the number of steps in your upgrade path.
Refer to the relevant section depending upon your current version of Citect SCADA.
Published June 2018