About Historian Data 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 or a cloud destination for archiving. The following image shows the data flow in a typical Historian system from a data source to the archive.
The following table provides a list of collectors, their usage, and whether each of them is toolkit-based and consumes a client access license (CAL).
Collector Name Description Is Toolkit-Based? Consumes a CAL?
The Calculation collector Performs data calculations on values stored in the archiver. No Yes
The iFIX Alarms and Events collector collector Collects alarms and events data from iFIX. No No
The iFIX collector Collects tag data from iFIX. No No
The MQTT collector Collects data published to a topic using an MQTT broker. Yes Yes
The ODBC collector Collects data from an application based on an ODBC driver. Yes Yes
The OPC Classic DA collector Collects data from an OPC Classic Data Access (DA) server (such as CIMPLICITY).
The OPC Classic HDA collector Collects data from an OPC Classic Historical Data Access (HDA) server (such as CIMPLICITY). Yes Yes
The OPC UA Data Access (DA) collector Collects data from an OPC UA DA server (such as CIMPLICITY). Yes Yes
The OSI PI collector Collects data from an OSI PI server. No No
The Python collector Run Python scripts on tag values and stores them in Historian No No
The Server-to-Server collector Collects data from a Historian server and sends it to another Historian server. No Yes
The Server-to-Server distributor Collects data from a smaller Historian server and sends it to a larger, centralized Historian server or a cloud destination. No Yes
The Simulation collector Generates random numbers and string patterns for testing/demonstration purposes. No No
The Wonderware collector Collects data from a Wonderware Historian 2014 R2 server. Yes Yes

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.

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.