node-red-contrib-piwebapi

Node-RED nodes for OSIsoft PI Web API with OMF support and real-time subscriptions.

Installation

``bash
npm install node-red-contrib-piwebapi
`

Or install directly from Node-RED palette manager.

Nodes

$3

#### PI Web API Config
Configuration node for PI Web API connection settings.
- Base URL: PI Web API endpoint (e.g., https://piserver/piwebapi)
- Username/Password: Basic authentication credentials
- Verify SSL: Enable/disable SSL certificate verification

$3

#### PI Point List
List PI Points from a PI Data Archive server.
- Filter by name pattern (e.g., sin, temperature*)
- Store results in global context for use by other nodes
- Returns WebId, name, and path for each point

#### PI Point Read
Read values from PI Points.
- Current Value: Get the latest value
- Recorded Values: Get historical data with time range
- Interpolated Values: Get evenly spaced interpolated data
- Plot Values: Get values optimized for plotting

Output format:
`javascript
{
topic: "PointName",
payload: 42.5,
time: "2024-01-18T12:00:00.000Z",
quality: "Good",
web_id: "F1DP...",
read_mode: "value"
}
`

#### Asset Read
Read attribute values from AF elements.

#### Attribute List
List attributes from AF elements.

$3

#### PI Point Write
Write values to existing PI Points.

Numeric values:
`javascript
msg.payload = 42.5;
msg.timestamp = new Date().toISOString();
msg.webId = "F1DP...";
`

Digital state values:
`javascript
msg.payload = {
Name: "Active",
Value: 1,
IsSystem: false
};
msg.timestamp = new Date().toISOString();
msg.webId = "F1DP...";
`

System digital states (Bad, Comm Fail, etc.):
`javascript
msg.payload = {
Name: "Comm Fail",
Value: 313,
IsSystem: true
};
`

$3

Use OMF to create new data streams in PI. Requires three steps:
1. Create Type (schema definition)
2. Create Container (stream/point)
3. Send Data

#### OMF Type Builder
Visual interface to define OMF type schemas.
- Set Type ID and classification (dynamic/static)
- Define properties with types and formats
- Mark index property (usually Timestamp)

#### OMF Container Builder
Create OMF containers (streams) that use defined types.
- Single container mode
- Multiple containers mode (batch creation)
- Select types from global context

#### OMF Writer
Send OMF messages to PI Web API.
- Message types: type, container, data
- Actions: create, update, delete
- Supports gzip compression

$3

#### Subscribe
WebSocket subscription to PI Point value changes.

PI Web API Configuration

$3

For OMF support, configure these in PI Web API Admin:

| Setting | Value |
|---------|-------|
| CorsMethods | GET,OPTIONS,POST,PUT |
| DisableWrites | False |
| OmfCreateMode | Insert |

$3

If EnableCSRFDefense is True, the nodes automatically include the X-Requested-With: XMLHttpRequest header.

Examples

$3


`
[Inject] -> [PI Point Read] -> [Debug]
`

$3

`
[Inject] -> [Function: Set Value] -> [PI Point Write] -> [Debug]
`

$3

`
[Inject] -> [OMF Type Builder] -> [OMF Writer] -> [Debug]
[Inject] -> [OMF Container Builder] -> [OMF Writer] -> [Debug]
[Inject] -> [Function: Build Data] -> [OMF Writer] -> [Debug]
`

$3

`javascript
msg.payload = [{
containerid: 'Sensor001',
values: [{
Timestamp: new Date().toISOString(),
Value: 23.5
}]
}];
msg.omfMessageType = 'data';
`

Global Context Integration

PI Point List can store discovered points in global context, making them available to other nodes via dropdown selection:

1. Configure PI Point List with a global context key (e.g., piPoints`)
2. Run the list operation
3. Other nodes (Read, Write) can select points from the dropdown

License

MIT

Author

Holger Amort

Repository

https://github.com/ErnstHolger/node-red-contrib-piwebapi