Key Concepts

A clear understanding of AVEVA Historian concepts is essential for using the SDK effectively and taking advantage of its features. Before using the SDK, you should be familiar with the following topics:

• Tags and their properties
• Tag storage rules, such as delta, cyclic, and forced
• Data categories, such as original, revision, streamed, and non-streamed data
• Data versions, such as original and latest
• The AVEVA Historian Client Access architecture, including components such as the Historian Client Access Layer (HCAL) and the Historian Client Access Point (HCAP)
• Store-and-forward functionality
• Retrieval modes, such as delta, cyclic, best fit, counter, and so on 
• Event storage and retrieval

For more information on these topics, see the AVEVA Historian Concepts Guide.