Supported versions

AVEVA Historian Client Web supports versions 1 and 2 of the Historian Data REST API.

Version 2

This is the current and recommended version of the Historian Data REST API.

Version 2 of this REST APis based on version 1 and includes further enhancements. Version 2 includes these differences from version 1:

• The datetimeoffset parameter is not supported as part of the DateTime syntax.

• While Raw and ProcessValue entities use DateTime, summary entities use StartDateTime and EndDateTime.

• For most version 2 queries, single quotes are not used for DateTime. For example:

  http://localhost:32569/Historian/v2/ProcessValues
  ?$filter=DateTime+gt+2017-07-13T00:00:00

  However, when querying events, single quotes are required for DateTime. For example:

  http://localhost:32569/Historian/v2/Events
  ?$filter=EventTime+gt+'2017-07-13T00:00:00'

  By contrast, version 1 queries do use single quotes for DateTime. For example:

  http://localhost:32569/Historian/v1/ProcessValues
  ?$filter=DateTime+gt+datetimeoffset'2017-07-13T00:00:00'

• TagProperty and Events entity types are now open type. That is, dynamic properties can be added to the response at runtime. This can be verified using $metadata endpoint URL:

  http://localhost:32569/Historian/v2/$metadata

  where there will be additional attribute, OpenType="true", under <EntityType> section.

• The Tags resource returns all the properties (fixed and extended) for a tag. A tag's extended properties will be added to the response only if they exist. (The extended property name will not be listed for tags that do not have a given extended property.)

• The combined Summary resource is not supported in version 2. Use the individual AnalogSummary and StateSummary resources instead to retrieve the summary of a tag.

• Version 2 adds support for the OData contains function for applicable resources and properties.

Version 1

This is the original version of Historian Data REST API based on the OData v4 specification.

• Version 1 uses the DateTime format used in this example:

  http://localhost:32569/Historian/v1
  /AnalogSummary?$filter=FQN+eq+'Baytown.tank_level'
  +and+StartDateTime+ge+datetimeoffset'2016-05-14T00:00:00.000-07:00'
  +and+EndDateTime+le+datetimeoffset'2016-05-16T00:00:00.000-07:00'