Rockwell Automation FactoryTalk Historian SE 3.0 H2H Interface User Guide - Manual (Page 7)

FactoryTalk Historian To Historian Interface User Guide 1
Chapter 1.
Introduction
The Rockwell FactoryTalk Historian to Historian interface copies tag data from one Historian
Server to another. Data is moved in one direction, meaning data is copied from the source to
the receiving Historian Server (also referred to as target Historian Server). The interface must
run on a Windows Intel-based operating system.
Note: The Rockwell FactoryTalk Historian to Historian interface functions and is
configured the same as the standard Rockwell Automation PItoPI interface, with the
exception that this interface can only connect to FT Historians.
Interface tags are created on the receiving Historian Server. Each interface tag is configured
to receive data for a unique source tag. Tags receive either archive or exception data updates
from the source tag. Exception data is data that has not yet been subjected to compression.
The type of data collection, exception or archive, is configured through scan class
assignment. By default, all tags belonging to the first scan class receive exception data. Tags
assigned to any other defined scan class receive archive data.
The interface supports history recovery. History recovery enables users to recover data for
time periods when the interface was not running or otherwise unable to collect data. The
history recovery period is configurable; the default is 8 hours. Users have the option of
performing time-range specific history recovery by specifying a start and end time. In this
configuration the interface collects data for the specified time period then exits.
Both source Historian Server-level failover and UniInt Phase 2 interface level failover are
supported. When running in source Historian Server-level failover mode, the interface obtains
data from one of two available source Historian Servers. The source Historian Servers must
have identical tag definitions and data streams for each interface source tag. This requirement
ensures the interface will obtain the same data regardless of which source server is active.
When running in UniInt Failover mode, two copies of the interface are connected to the
source Historian Server at the same time. When the primary interface stops collecting data,
the backup interface assumes the primary role and continues data collection. Source Historian
Server-level failover and UniInt Phase 2 interface level failover modes can be run
simultaneously. Failover maximizes interface data availability on the receiving Historian
Server(s).
Interface Limitations
The FactoryTalk Historian to Historian interface is not a true data replication tool. It does not
synchronize Historian Server data or perform data validation. It simply provides a method for
copying data from one Historian Server to another in an incremental, time forward manner.
There is no guarantee that an exact archive data match will exist between the source and
receiving Historian Servers. If the goal is to achieve data matching (replication) Rockwell