Working with AppEngine Redundancy

You enable AppEngine redundancy in the Primary AppEngine. You must also configure two WinPlatforms for redundancy, one to host the Primary AppEngine and one to host the Backup AppEngine.

The configuration of both WinPlatforms should be the same. At a minimum, the store-forward directory configurations must be common to both WinPlatforms:

During configuration, you can assign Primary and Backup AppEngines to the same WinPlatform. To deploy, you must assign the Primary and Backup AppEngines to different WinPlatforms.

Each production computer hosting a redundancy-enabled AppEngine must have a minimum of two network cards. One NIC is for the supervisory network and PLC network, if the computer has only two network cards. The other must be for a dedicated Ethernet connection between computers for the redundancy message channel (RMC).

For information about distributed networks, see Multiple network interface cards.

The RMC handles redundancy monitoring, message handling and data synchronization between redundant pairs.