aveva/sample-adh-data_hub_to_pi-python

CONNECT data services to PI Data Archive Python Sample

Version: 1.0.4

Developed against Python 3.9.1.

Requirements

• Python 3.7+
• Register a Client-Credentials Client in your CONNECT data services tenant and create a client secret to use in the configuration of this sample. (Video Walkthrough)
  • Note: the client only needs role with read permissions to the specified streams.
• Install required modules: pip install -r requirements.txt
• Requires the PI Web API and that the default server of the PI Web API is the desired server to send to.

About this sample

This sample uses REST API calls to the Sequential Data Store of CONNECT data services to collect Types, Streams, and data and create corresponding PI Tags in a Data Archive. The sample uses the architecture outlined below where data is fed into a queue from a data retrieval task and events are read from the queue by the send task to be sent to the PI Data Archive. Within the retrieval task, individual threads are spun up to parallelize data retrieval, improving performance. Within the send task, data is batched together from any number of streams and sent when there are more than 5000 events to be sent or more than 30 seconds has elapsed. This ensures that data is sent in order and is more performant than continuously sending data.

Configuring the sample

The sample is configured by modifying the file appsettings.placeholder.json. Details on how to configure it can be found in the sections below. Before editing appsettings.placeholder.json, rename this file to appsettings.json. This repository's .gitignore rules should prevent the file from ever being checked in to any fork or branch, to ensure credentials are not compromised.

There are some PI Point settings that cannot be configured programatically through OMF, but may be desireable. Compression for example is enabled by default on most PI Data Archives so not all data will be archived by default. To modify a PI Point's configuration, first run the sample until the new PI Points have been created, then modify them using either PI System Management Tools or PI Builder in Excel.

Configuring appsettings.json

CONNECT data services is secured by obtaining tokens from its identity endpoint. Client-credentials clients provide a client application identifier and an associated secret (or key) that are authenticated against the token endpoint. You must replace the placeholders in your appsettings.json file with the authentication-related values from your tenant and a client-credentials client created in your Cds tenant.

{
  "DataHub": {
    "Resource": "https://uswe.datahub.connect.aveva.com",              # This is the base Cds URL being used
    "ApiVersion": "v1",                                                # The API version
    "TenantId": "PLACEHOLDER_REPLACE_WITH_TENANT_ID",                  # The Tenant Id of the Tenant that is being read from
    "NamespaceId": "PLACEHOLDER_REPLACE_WITH_NAMESPACE_ID",            # The ID of the Namespace that is being read from
    "CommunityId": null,                                               # The ID of the Community that is being read from (If specified the Namespace Id will be ignored)
    "ClientId": "PLACEHOLDER_REPLACE_WITH_APPLICATION_IDENTIFIER",     # The ID of a client with the necessary permissions
    "ClientSecret": "PLACEHOLDER_REPLACE_WITH_APPLICATION_SECRET"      # The Secret of the above client
  },
  "PI": {
    "Resource": "PLACEHOLDER_REPLACE_WITH_PI_WEB_API_URL",             # The URL of the PI Web API server (Should end in /piwebapi)
    "Username": "PLACEHOLDER_REPLACE_WITH_USERNAME",                   # The username of the account used to authenticate to the PI Web API
    "Password": "PLACEHOLDER_REPLACE_WITH_PASSWORD",                   # The password of the account used to authenticate to the PI Web API
    "VerifySSL": true                                                  # A feature flag for verifying SSL when connection to the PI Web API. It is true by default as we strongly recommended that SSL be checked.
  },
  "Queries": [
    {
      "Value": "Id:StreamDemo1"                                        # A search string to find streams to be transferred. Multiple queries may be specified and they adhere to SDS search syntax.
    },
    {
      "Value": "S*"
    }
  ]
}

Running the sample

To run this example from the command line once the appsettings.json is configured, run

python program.py

To quit the application type exit in the terminal and hit Enter at any time after prompted.

Running the automated test

To test the sample, start by setting Queries in the appsettings.json to

"Queries": [
  {
    "Value": "Id:DataHubToPIStream"
  }
]

Then run

python test.py

---

Tested against Python 3.9.1

For the main Cds samples page ReadMe
For the main AVEVA samples page ReadMe