About Historian Data Collectors

Many data collectors bring data into the Historian server, as listed in Supported Windows Versions for Historian Collectors.

Since installation, maintenance, and troubleshooting from a Historian perspective are essentially the same for all collectors other than the File collector, this chapter summarizes the characteristics of each and highlights their differences. It also provides a detailed description for the File collector, since it differs from the other types of collectors.

A data collector gathers data from a data source on a schedule or event basis, processes it, and forwards it to the Historian server for archiving. The following image shows the data flow in a typical Historian system from a data source to the archive.

Data collectors use a specific data acquisition interface that match the data source type, such as iFIX Easy Data Access (EDA) or OPC 1.0 or 2.0 (Object Linking and Embedding for Process Control). For more information, see Supported Acquisition Interfaces. The Simulation collector generates random numeric and string data. The File collector reads data from text files.

The following table provides information on whether each collector is toolkit-based and whether is consumes a CAL.


Collector Name	Is Toolkit-Based?	Consumes a CAL?
The Calculation collector	No	Yes
The Cygnet collector	Yes	Yes
The File collector	No	No
The iFIX Alarms and Events collector collector	No	No
The iFIX collector	No	No
The MQTT collector	Yes	Yes
The ODBC collector	Yes	Yes
The OPC Classic Alarms and Events collector	No	No
The OPC Classic HDA collector	Yes	Yes
The OPC UA DA collector	Yes	Yes
Th OPC UA Data Access (DA) collector	No	No
The OSI PI collector	No	No
The Server-to-Server collector	No	Yes
The Server-to-Server distributor	No	Yes
The Simulation collector	No	No
The Windows Performance collector	Yes	Yes
The Wonderware collector	Yes	Yes

Limitations:

When failover occurs from a primary collector to a secondary collector (or vice versa), there will be some data loss as the collector tries to connect to the source to fetch the data.