The System Parameter Allow Originals applies to which type of Historian tag category?

The System Parameter Allow Originals is specifically associated with the IDAS tag category, which stands for Input Data Management System (IDAS). This parameter allows the historian to retain original values of the data before they are processed or recalibrated. In data acquisition and management, particularly in real-time systems, it is important to track the original values for reference, auditing, or data correction purposes.

When this parameter is enabled for IDAS tags, it ensures that the raw data is preserved alongside any processed data. This can be especially useful in scenarios where data transformation or calculations take place after the data is collected, enabling analysts to have access to both the original readings and the modified data. Understanding the use and implications of this parameter helps ensure accurate data management and retrieval in the historian system, making it a crucial aspect for those working with IDAS tags.

In contrast, the other tag categories (ODAS, RDAS, SDAS) do not utilize this specific parameter, as they pertain to different data handling and storage functionalities within the AVEVA Historian framework. Hence, their operational context does not encompass the same need for retaining original input values as IDAS does.