Data acquisition components

I/O Server (DAServer)

AVEVA-compatible software application that reads values from PLCs and other factory devices and forwards the real-time data to AVEVA applications.

Query Tools

Any database query tool capable of issuing Transact-SQL INSERT or UPDATE statements; for example, Microsoft SQL Server Query Analyzer.

Data Import Folder

Defined file folder to batch import tag values to the Historian.

Historian Data Importer

Utility to import data from one or more CSV files or InTouch history files (.lgh). For more information, see Import history data.

Historian Client Access Layer (HCAL)

Process that can send non-I/O Server data to the Historian to be historized. HCAL is used by Application Server 2012 R2 or later and custom client applications built with Historian SDK 2012 R2 or later.

Historian Client Access Point (HCAP)

Process that can accept non-I/O Server data and send it to the Historian to be historized. HCAP is used by Application Server 2012 R2 or later and custom client applications built with Historian SDK 2012 R2 or later.

System Driver Service

Internal process that monitors the entire Historian system and reports the status with a set of system tags. The system driver also sends data values to the Storage subsystem for the current date and time, as well as for predefined "heartbeat" tags, such as a discrete system pulse. For more information, see About system driver and system tags.