Rockwell Automation FactoryTalk Historian SE 3.0 UniInt Interface User Guide - Manual (Page 57)

UniInt Interface User Manual 51
Point Synchronization and Historian Server Connections
An interfaces using the disconnected startup configuration has the ability to synchronize
interface point configuration data with that of the host Historian Server. With interfaces built
with older versions of UniInt that did not support disconnected startup, if the connection to
the Historian Server was lost after interface startup, point modifications made on the
Historian Server while the interface was disconnected were not retrievable by the interface
once the connection to the Historian Server was restored. The interface needed to be
restarted to get the latest point information.
With disconnected startup configured, point information for the interface will be
synchronized with the Historian Server once a valid connection to the Historian Server
becomes available. For example, an interface is started using the disconnected startup
configuration. The connection to the Historian Server is lost due to a network failure or some
other reason. While the interface connection to the Historian Server is down, the
administrator modifies the point database. The connection to the Historian Server is now
available. The interface now synchronizes its point cache to match the current point
configuration on the Historian Server. Without restarting the interface, points that were
created on the Historian Server while disconnected are added to the interface. Similarly,
edited points are updated in the interface and deleted points are removed from the interface.
Note: Point changes made on the Historian Server while the interface is running but
disconnected from the Historian Server will generate informational messages, in
the pipc.log file, relating to point creation, editing, or deletion as appropriate. These
messages will appear once per point modification. In some cases, an error
message may be generated due to data being sent to Historian Points that no
longer exist on the Historian Server. Typically, the interface only logs one message
for a given error code only once per point that is in error. These informational and
error messages are normal and should require no action by the user.
Point Modifications on the Historian Server and Interface Restarts
An interface started using the disconnected startup configuration loads points designated for
the interface from locally stored cache files. This means that the interface only retrieves
point information from the Historian Server during normal updates or during point
synchronization. Therefore, changes made in Historian point database will show up in the
interface as a typical point create, edit, or delete and users will notice pipc.log file messages
showing point create, edit, or delete information relating to the modifications made to the
Historian point database. The interface typically process its first point update 2 minutes after
starting up and processes 30 point updates at a time. If more than 30 updates are pending,
they will be processed at a rate of 30 updates every 30 seconds. Interfaces that experience
numerous point changes will require additional time before the interface handles all the point
changes.
It is recommended to run the interface in the non-disconnected startup mode while making
major point modifications to the host Historian Server. Moreover, move or delete any
previously created cache files for the interface to prevent the interface from using the
outdated cache files during subsequent restarts when the disconnected startup feature is