OSISoft WebAPI Subscriber Documentation

Version: 1.2.0

Retrieved: 2025-10-09 15:16:10

OSISoft Pi WebAPI Subscriber

The module is used to subscribe to changes from an OSISoft Pi WebAPI Server. The module will setup a subscription for all configured tags and receive messages when tags are changed in the OSI Server.

Settings

Name Requirements Purpose Default
URL String with length 1-256 The URL of the WebAPI server to use ``
Credential Username/Password The user with access to the PI Server ``
Allow Untrusted Certificates Boolean For example when the server has a self-signed certificate false
Target Property String with length 1-64 The property on the outgoing message that will contain the result data
Include Initial Values Boolean If true the current value for all points subscribed to will be instantly sent out false
Tags collection (Resource) See Resource file format File that contains all asset-servers and/or data-servers to read ``
Data Server Name String with length 0-64 The data server for additional tags to monitor ``
Additional tags to monitor List of strings   ``

Resource file format

Note that both Metadata and webId are optional, however if webId is omitted the performance will be very poor since the module have to collect the webId for each tag before the module can start. Omitting the webId for the DataServer is not as bad as omitting the webId for the tags, but performance will always be improved if webId is configured.

{
  "dataServers": [
    {
      "webId": "F1DSA_IIvCccC0KbowWzAt8ruAMTAuMC4wLjI",
      "name": "10.0.0.2",
      "items": [
        {
          "name": "BA:LEVEL.1",
          "webId": "F1DPA_IIvCccC0KbowWzAt8ruABwAAAAMTAuMC4wLjJcQkE6TEVWRUwuMQ",
          "metaData": { "foo": "bar" }
        },
        {
          "name": "BA:CONC.1",
          "webId": "F1DPA_IIvCccC0KbowWzAt8ruACAAAAAMTAuMC4wLjJcQkE6Q09OQy4x",
          "metaData": { "foo": "baz" }
        }
      ]
    }
  ]
}

Example 1

Subscribing to a single tag using Data Server Name and Additional Tags setting

Settings

URL: 'https://myPiServer.com'
Allow Untrusted Certificates: 'true'
Target Property: 'data'
Data Server Name: '10.0.0.2'
Additional tags to monitor: ['BA:LEVEL.1']

Output

{
  "data": {
    "items": [
      {
        "items": [
          {
            "annotated": false,
            "good": true,
            "questionable": false,
            "substituted": false,
            "timestamp": "2023-04-17T07:53:05Z",
            "unitsAbbreviation": "",
            "value": 41.7179337
          }
        ],
        "name": "BA:LEVEL.1",
        "webId": "F1DPA_IIvCccC0KbowWzAt8ruABwAAAAMTAuMC4wLjJcQkE6TEVWRUwuMQ"
      }
    ]
  },
  "crosser": {
        "success": true
  }
}

Example 2

Subscribing to tags using a Tags collection (Resource) file

Settings

URL: 'https://myPiServer.com'
Allow Untrusted Certificates: 'true'
Target Property: 'data'
Tags collection: {
  "dataServers": [
    {
      "webId": "",
      "name": "10.0.0.2",
      "items": [
        {
          "name": "BA:LEVEL.1",
          "webId": "",
          "metaData": { "foo": "sample metadata for BA:LEVEL.1" }
        },
        {
          "name": "BA:CONC.1",
          "webId": "",
          "metaData": { "foo": "sample metadata for BA:CONC.1" }
        }
      ]
    }
  ]
}

Output

{
  "data": {
    "items": [
      {
        "items": [
          {
            "annotated": false,
            "good": true,
            "questionable": false,
            "substituted": false,
            "timestamp": "2023-04-17T07:53:05Z",
            "unitsAbbreviation": "",
            "value": 41.7179337
          }
        ],
        "name": "BA:LEVEL.1",
        "webId": "F1DPA_IIvCccC0KbowWzAt8ruABwAAAAMTAuMC4wLjJcQkE6TEVWRUwuMQ",
        "MetaData": { "foo": "sample metadata for BA:LEVEL.1" }
      },
      {
        "items": [
          {
            "annotated": false,
            "good": true,
            "questionable": false,
            "substituted": false,
            "timestamp": "2023-04-17T07:53:05Z",
            "unitsAbbreviation": "",
            "value": 31.3271389
          }
        ],
        "name": "BA:CONC.1",
        "webId": "F1DPA_IIvCccC0KbowWzAt8ruACAAAAAMTAuMC4wLjJcQkE6Q09OQy4x",
        "MetaData": { "foo": "sample metadata for BA:CONC.1" }
      }
    ]
  },
  "crosser": {
        "success": true
  }
}

Search Documentation

Data Sources

AVEVA Modules