Rockwell Automation FactoryTalk Historian SE 3.0 H2H Interface User Guide - Manual (Page 52)

Historian Point Configuration
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Interface Configurations
Data collected by the interface has already passed exception on the source Historian Server.
For this reason interface exception filtering should be disabled. This can be done by
specifying the
/sn switch in the startup configuration file. This tells the interface to bypass
exception and send data directly to the snapshot table on the receiving Historian Server.
By default the interface will send history recovery and archive update data directly to the
receiving Historian Server archive. The data write mode is configurable through the
Location5 tag attribute. If the /dc switch is specified in the interface startup file, data will
pass through compression on the receiving Historian Server regardless of server version. If
the receiving Historian Server is Historian 3.2 or Historian 2 data is always subjected to
compression whether or not the
/dc switch is used.
Note: if a tag configured for archive data updates has its Location3 attribute set so it
receives snapshot updates, data compression must be enabled to eliminate data mismatches
between Historian Servers.
Recommended Tag Configurations
Each tag has attributes that are used to define exception and compression data filtering. These
attributes specify a significant data change and the minimum and maximum time between
events.
The following tag configurations are recommended to prevent data mismatches:
Tag Attribute Value
ExcDev/ExcDevPercent 0
CompDev/CompDevPercent Source Tag Value
ExcMin & CompMin 0
ExcMax & CompMax 32767
The ExcDev / ExcDevPercent and CompDev / CompDevPercent attributes define a
significant data change. A new update must pass this value to pass data filtering.
The ExcMax and CompMax tag attributes set the maximum number of seconds between
updates. When the value of this attribute is exceeded, the next update passes filtering
regardless of whether or not it is a significant change in value. Tags should be configured
with the maximum allowed values.
The ExcMin and CompMin tag attributes set the minimum number of seconds between
updates. If a new value is received and the time difference between the new value and the
current value does not exceed this value the update is filtered. Tags should be configured with
a value of zero to prevent data from being filtered because of the time between updates.
By default, the largest ExcMax and CompMax values the interface supports is 32,767 seconds
(~9hours). If the receiving Historian Server was a new installation of PI 3.3 or later, it is
possible to have
ExcMax and CompMax values of 4,294,967,295 seconds. In addition to the
server version, the PI SDK must be enabled in the interface startup file by specifying
/pisdk=1 .