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AVEVA Web Client

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InTouch LGHProvider Service

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  • Last UpdatedApr 29, 2026
  • 2 minute read

The InTouch LGHProvider Service supports LGH-based trending in the VisCore-based Web Client. This service enables VisCore components to retrieve and visualize historical data that is logged locally by InTouch.

Service responsibilities

Local Data Access

  • Reads LGH (Local Gateway Historian) data directly from the InTouch node.

  • Uses LGH SDK APIs for data retrieval.

API Exposure

  • Exposes retrieved historical data through OData‑based HTTP/REST APIs.

  • These APIs are consumed by VisCore for visualization.

Data Format

  • Returns data in a time-series OData JSON format.

  • The format is optimized for the following VisCore components:

    • Trend Pen

    • Trend Client

Deployment and lifecycle

  • The InTouch LGHProvider Service is InTouch-specific and is available only as part of the InTouch product deployment.

  • The service is automatically deployed and started during application deployment using the InTouch Application Manager.

  • The service is restarted with every application deployment to ensure that the service reflects the latest application configuration and runtime context.

Historical data configuration behavior

InTouch applications support configuration of the following historical data sources:

  • LGH (Local Historical Logging)

  • Historian Server

Additionally, graphics, such as Trend controls, can also be configured to use a specific historical data source

For 2026 version, trend data is retrieved from only one provider at a time, based on the configuration:

  • Only LGH configured: Trend Pen and Trend Client retrieve data only from LGH.

  • Only Historian configured: Trend Pen and Trend Client retrieve data only from the Historian.

  • Both LGH and Historian configured: Trend Pen and Trend Client default to Historian as the data source.

    Note: Simultaneous plotting of data from both LGH and Historian is not supported in the 2026 version.

Configuration management

A dedicated configuration file is used to manage InTouch‑specific settings: ProgramData/VCP/ViewApps/InTouch/InTouchConfigSettings.Config

This file is used to store InTouch‑specific configuration details, and is used for:

  • Selecting the historical data source (LGH or Historian)

  • Storing related service configuration parameters

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