Rockwell Automation FactoryTalk Historian SE 3.0 H2H Interface User Guide - Manual (Page 12)

Introduction
6
SetDeviceStatus
The Historian to Historian Interface is built with UniInt 4.4.4.0. New functionality has been
added to support health tags. The Health tag with the point attribute
ExDesc =
[UI_DEVSTAT] represents the status of the source device. The following events can be
written into this tag:
“1 | Starting” - the interface is starting.
 “Good” - the interface is properly communicating and reading data from the server.

The following event represents a failure to communicate with the server:
o "3 | 1 device(s) in error | Network communication error to source Historian
Server"
o "3 | 1 device(s) in error | Unable to get archive data from source Historian
Server"
o "3 | 1 device(s) in error | Unable to get snapshot data from source Historian
Server"
o "3 | 1 device(s) in error | Unable to write data to receiving Historian Server"
o "3 | 1 device(s) in error | Unable to obtain current data with source Historian
Server failover enabled."
 “4 | Intf Shutdown” - the interface is stopped.
Refer to the UniInt Interface User Manual for more information on how to configure health
points.
Failover
Source Historian Server-Level Failover Support
Source Historian Server-level failover maximizes interface data availability on the receiving
Historian Server(s). It enables the interface to obtain data from one of two source Historian
Servers. Each source server must have identical tag definitions and data streams for interface
source points. Source Historian Server failover is not supported for Historian 2.
The interface will initiate failover if the active source data becomes stale or is not available
due to network issues. The Historian Interface Status utility is required for each source
Historian Server to monitor data quality. The interface uses the utility status tag output to
verify source data is current and has not become stale.
UniInt Interface Failover Support
UniInt Phase 2 Failover provides support for cold, warm, or hot failover configurations. The
Phase 2 hot failover results in a no data loss solution for bi-directional data transfer between
the Historian Server and the Data Source given a single point of failure in the system
architecture similar to Phase 1. However, in warm and cold failover configurations, you can
expect a small period of data loss during a single point of failure transition. This failover
solution requires that two copies of the interface be installed on different interface nodes
collecting data simultaneously from a single data source. Phase 2 Failover requires each
interface have access to a shared data file. Failover operation is automatic and operates with
no user interaction. Each interface participating in failover has the ability to monitor and
determine liveliness and failover status. To assist in administering system operations, the
ability to manually trigger failover to a desired interface is also supported by the failover
scheme.