Local Station

A container of read-only “Sys Def” properties that reflect what information would be “sync’ed up” to a remote Supervisor station (if the local station was defined as a subordinate). Sys Def is potentially of use to developers. For details, About Sys Def components.

Sys Def Provider

A container for “Sys Def” child components, of type “ProviderStations”, which are typically hidden slots (by default). The API interacts with this component to query about the “Sys Def” hierarchy, and persists this definition. Sys Def is chiefly of interest to NiagaraAX developers working with the API. For details, About Sys Def components.

Fox Service

A container for Fox protocol settings affecting client connections made to the local station, such as from Workbench or from another station. Such connections appear locally as “server connections.” For details, see About the Fox Service.

History Policies

A container for “rules” that specify how remotely-generated histories should be changed when these histories are pushed into the station (that is, exported from remote stations). Also contains a poll scheduler for “on demand” polling of histories. For details, see History Policies.

Workers

A container with a configurable property “Max Threads”. This property allows tuning for large Niagara networks (many NiagaraStation components), and is the only visible part of a “shared thread pool scheme” for large-job scalablilty. In current releases, station work from a single station was limited to one thread, and the former default value of 50 was changed to a “max” value. This allows the local station’s thread pool to grow uncapped while alleviating a former thread starving issue.

Very large Supervisors with many stations may benefit from Niagara thread pool adjustments made via entries in the host’s system.properties file. Consult your support channel for details.