Phase 1

UniInt Failover Phase 1 is supported on a per-interface basis for interfaces built with UniInt 4.2.0.0 and later. See the individual interface user guide for the type of failover supported by the interface.

If an interface does not support UniInt failover, the UniInt Failover page displays a message in the status line at the bottom.

• Enable UniInt Failover

  This page is enabled if the interface supports UniInt failover. Check Enable UniInt Failover to enable failover for the selected interface.

• Phase 1 / Phase 2

  If the interface supports both types of failover, you must choose which type to use. If the interface supports only one type of failover, the other type is disabled. This must be the first item selected when you configure failover.

• Failover ID# for this instance

  In a failover interface installation, each copy of the interface has its own unique positive integer identifier. This identifier is referred to as the failover ID and is specified with the interface startup parameter /UFO_ID=n.

• Failover ID# of the other instance

  This is the failover ID assigned to the other interface in the failover pair. By default, the pairs are named 1 and 2.

  See Select the other interface of a failover pair.

• Do Not Failover when both interfaces lose connection to PI

  This option can only be used with interfaces built with UniInt 4.5.1.0 and later. It is used to prevent the primary and the backup failover pair from both buffering data when they have lost connection to PI Server. The equivalent startup parameter is /UFO_DNFBPI.

• Failover control tags are unsolicited (not scan based)

  This option can only be used with unsolicited input interface failover control points. If the interface supports scan-based input data and the interface failover points are defined as scan-based input points, the update interval is then defined by the scan class to which the control points belong.

  The failover update interval determines the rate at which UniInt updates the heartbeat points, how long it takes for the interface to failover, and how much overlapping data may be sent to PI Server. The optional /UFO_Interval=# startup parameter specifies the failover update interval for unsolicited failover control points.

  Both interface copies participating in failover must use the same failover update interval. The failover update interval, #, is specified in milliseconds with the default being 5000 milliseconds or 5 seconds. The minimum interval is 50 milliseconds.

  The failover update interval can be changed in the Rate at which the heartbeat point is updated/checked field.