H4TagDictionary

With the Haystack 4 tag dictionary, most items come directly from the unaltered Project Haystack source files (see https://project-haystack.org/download). This provides the benefit that it does not require post-processing of Project Haystack sources to supply information necessary to Niagara. The latest version of these source files at the time of the release of Niagara is packaged with the haystack-rt module. Newer versions that were released later by Project Haystack may be used instead of the packaged versions.

As of Niagara 4.13, the Haystack 4 tag dictionary primarily uses defs.json and protos.json files produced by Project Haystack to generate the dictionary’s tags, tag groups, relations, and tag rules.

Defs.json contains information about all tags, all relations, and tag groups based on conjuncts. It also contains the tag hierarchy that is used to create most tag rules.

Protos.json contains additional tag groups.

An additional configuration file is used to assist with the dictionary generation, and add tag rules as well as smart tag types that enable some tagging convenience features. A default file is packaged with haystack-rt, but you can reference your own, if required. For stations already tagged in Haystack 3, a migration action adds Haystack 4 items that are equivalent to the Haystack 3 versions.

The Haystack 4 tag dictionary’s namespace is h4.

H4TagDictionary

Related Links