Rockwell Automation 1756-HIST2G FactoryTalk Historian ME 2.2 - Manual (Page 287)

F • D ESIGN C ONSIDERATIONS AND L IMITATIONS
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third-party h istorians or other upstream servers, use FactoryTalk Historian
DataLink to move data out of the module.
Observe the following Data Transfer subsystem limits on the module:
„
Transfer a minimum of 5,000 events per transfer session to the FactoryTalk
Historian SE or PI server archive.
„
Transfer a maximum of 150,000 events to the FactoryTalk Historian SE or PI
server archive.
Data Storage
This section contains Data Storage considerations. FactoryTalk Historian ME is
available in two versions: one with 1GB of total storage, and one with 2GB of total
storage.
„
Observe the following archive file size limits on the module:
„
The 1GB module has an effective archive storage capacity of 0.5GB because
approximately 500MB is used for the operating system, firmware, and log files.
The 2GB module has an effective archive storage capacity of 1.5GB.
„
The on-board data storage for FactoryTalk Historian ME is limited. Using a Data
Transfer rate of 2500 events per second (the maximum transfer rate available)
without Compression or Exception Filtering, the on-board storage capacity is
approximately four hours for the 1GB module and 14 hours for the 2GB module.
Therefore, Rockwell highly recommends that you include the FactoryTalk
Historian SE or PI server for data aggregation when long-term storage is required.
By applying Compression and Exception Filtering, you can significantly improve
archive space from approximately two to ten times, depending on variables such
as how much the data varies between scans. To estimate archive performance with
and without Compression and Exception Filtering, can use a typical factor of 5.
Module Type File Size Number of Files Disk Space for
Archive
1G 10MB 40 files 400MB
2G 10MB 130 files 1.3GB