Rockwell Automation 1756-HIST2G FactoryTalk Historian ME 2.2 - Manual (Page 290)

F ACTORY T ALK H ISTORIAN ME M ODULE U SER G UIDE
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Hardware
ControlLogix Chassis
This section lists considerations related to the ControlLogix chassis.
„
Connect up to a maximum of 4 controllers in the same ControlLogix chassis.
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A maximum of 2 FactoryTalk Historian ME modules in a single chassis.
„
The module does not support a redundant controller chassis.
Once the FactoryTalk Historian ME module is running in a particular slot, Rockwell
does not recommend moving the module to a new slot because this may result in the
same tags being considered as different points.
Logix Controllers
This section lists considerations related to the Logix controllers.
„
The number of controllers that can transfer data to one Factory Talk Historian ME
is 4.
„
Data Collection should be stopped before creating tags to avoid creating excess
trend objects in the controller, consuming more controller memory.
„
FactoryTalk Historian ME can only connect to the controllers in the chassis it is
placed in. This means it can only connect to ControlLogix controllers; it cannot
connect to either ControlLogix or other controllers in another chassis.
If FactoryTalk Historian ME must connect to data in other chassis hardware such
as non-ControlLogix or third-party controllers, you can configure a ControlLogix
controller to act as a concentrator in the same chassis. This controller can then be
configured to expose the data from the remote controllers to the Factory Talk
Historian ME. However, it is critical to consider the increased load that an extra
data server will introduce in a ControlLogix system when configuring Data
Collection.
„
FactoryTalk Historian ME’s data gathering and trending impact on a Logix
controller is dependent on the configuration of the ControlLogix system. This
includes the available Logix controller bandwidth as well as the number of tags
being trended and the sample period. The Logix controller bandwidth is
determined by the type of controller, free memory, communication system
overhead time slice, and user application programs.