Data synchronization between PSS and SSS

In normal operating mode, the PSS has a connection to the field devices (Master Control Stations with OPS UA port) and the drivers run only on the PSS. Synchronization of the online data (process data) between the PSS and the SSS is done by a special control manager and the distributed systems mechanism, which uses the WinCC OA DIST manager to communicate the data from the PSS to the SSS, thus maintaining the last value datasets identically. All data points or data point types whose values are synchronized between the two systems must be configured using the corresponding configuration tables (see Configuration - Introduction). The prerequisite for this is that both distributed systems contain the same data points. This is achieved in the current mode via the synchronization of the data point configuration.

The synchronization of the (data point) configuration is achieved on the one hand by using WinCC OA control functions (time functions) and the WinCC OA ASCII manager. At a freely selectable interval (default is 60 minutes), the changed configuration data is exported from the primary system and then imported into the secondary system. This synchronization can also be deactivated if the configuration data from the PSS should not be processed periodically to the SSS, or if no more configuration data is to be processed after the first automatic synchronization process because no further configuration changes are expected on the system.

The synchronization of the historical data is resolved via the RDB functions. This synchronization is required in order to completely synchronize the systems again after a fallback, so that the historical polling of the databases on both systems returns the same result.