StreamSet GetChannel

Opens a channel that will send messages about any value changes for the attributes of an Element, Event Frame, or Attribute. See Channels for more information.

Request

GET streamsets/{webId}/channel

URL Parameters

• webId

  The ID of an Element, Event Frame or Attribute, which is the base element or parent of all the stream attributes. See WebID for more information.

• nameFilter

  The name query string used for filtering attributes. The default is no filter. See Query String for more information.

• categoryName

  Specify that included attributes must have this category. The default is no category filter.

• templateName

  Specify that included attributes must be members of this template. The default is no template filter.

• searchFullHierarchy

  Specifies if the search should include attributes nested further than the immediate attributes of the searchRoot. The default is 'false'.

• showExcluded

  Specified if the search should include attributes with the Excluded property set. The default is 'false'.

• showHidden

  Specified if the search should include attributes with the Hidden property set. The default is 'false'.

• includeInitialValues

  Specified if the channel should send a message with the current values of all the streams after the connection is opened. The default is 'false'.

• heartbeatRate

  Specifies the maximum number of consecutive empty messages that can be elapsed with no new data updates from the PI System, after which the client receives an empty payload. It helps to check if the connection is still alive. Zero/negative values correspond to no heartbeat, and the default value is no heartbeat.

• webIdType

  Optional parameter. Used to specify the type of WebID. Useful for URL brevity and other special cases. Default is the value of the configuration item "WebIDType". See WebID Type for more information.

Status Codes

101: Switches to the Web Socket protocol.

409: Unsupported operation on the given AF object.

Sample Response Body

{
  "Items": [
    {
      "WebId": "I1AbEDqD5loBNH0erqeqJodtALAYIKyyz2F5BGAxQAVXYRDBAGyPedZG1sUmxOOclp3Flwg",
      "Name": "Water",
      "Path": "\\\\MyAssetServer\\MyDatabase\\MyElement|Water",
      "Value": {
        "Timestamp": "2014-07-22T14:00:00Z",
        "UnitsAbbreviation": "m",
        "Good": true,
        "Questionable": false,
        "Substituted": false,
        "Annotated": false,
        "Value": 12.3
      },
      "Links": {
        "Self": "https://localhost.osisoft.int/piwebapi/attributes/I1AbEDqD5loBNH0erqeqJodtALAYIKyyz2F5BGAxQAVXYRDBAGyPedZG1sUmxOOclp3Flwg"
      }
    },
    {
      "WebId": "I1AbEDqD5loBNH0erqeqJodtALAYIKyyz2F5BGAxQAVXYRDBAGyPedZG1sUmxOOclp3Flwg",
      "Name": "Water",
      "Path": "\\\\MyAssetServer\\MyDatabase\\MyElement|Water",
      "Value": {
        "Timestamp": "2014-07-22T14:00:00Z",
        "UnitsAbbreviation": "m",
        "Good": true,
        "Questionable": false,
        "Substituted": false,
        "Annotated": false,
        "Value": 12.3
      },
      "Links": {
        "Self": "https://localhost.osisoft.int/piwebapi/attributes/I1AbEDqD5loBNH0erqeqJodtALAYIKyyz2F5BGAxQAVXYRDBAGyPedZG1sUmxOOclp3Flwg"
      }
    }
  ],
  "Links": {}
}