/sample-pi_web_api-common_actions-python

Primary LanguagePythonApache License 2.0Apache-2.0

PI Web API Python Sample

Version: 1.0.33

Build Status

The sample code in this folder demonstrates how to utilize the PI Web API using Python. You must have already installed Python in order to run this sample application.

Getting Started

To run the sample code:

  • Clone the GitHub repository
  • Open the "sample-pi_web_api-common_actions-python" folder with your IDE
  • Install the required modules by running the following command in the terminal: pip install -r requirements.txt
  • Run the application using the following command in the terminal: python .\program.py where program.py is the program you want to run. e.g python .\create_sandbox.py

Getting Started with Tests

To run the sample tests:

  • The sample test is configured using the file appsettings.placeholder.json. Before editing, 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.
  • Open the test config file appsettings.json
  • Replace the values with your system configuration.

For example:

{
  "Resource": "PLACEHOLDER_REPLACE_WITH_PI_WEB_API_URL",
  "DataArchiveName": "PLACEHOLDER_REPLACE_WITH_DATA_ARCHIVE_NAME",
  "AFServerName": "PLACEHOLDER_REPLACE_WITH_AF_SERVER_NAME",
  "Username": "PLACEHOLDER_REPLACE_WITH_USERNAME",
  "Password": "PLACEHOLDER_REPLACE_WITH_PASSWORD",
  "AuthType": "kerberos",
  "VerifySSL": true
}
Parameters Required Type Description
Resource required string The URL of the PI Web API
DataArchiveName required string The name of the PI Data Archive that is being sent to
AFServerName required string The name of the AF server that is being sent to
Username required string The username that is being used for authenticating to the PI Web API
Password required string The password that is being used for authenticating to the PI Web API
AuthType optional string The type of authentication to use when connecting to the PI Web API. By default this is set to "kerberos"
VerifySSL optional boolean A feature flag for verifying SSL when connecting to the PI Web API. By default this is set to true

  • Each test file (prefixed as "test_..."), can be run independently or all the tests can be run in a single instance via the run_all_tests.py file. Note: while the tests can be ran individually, some test database, elements, templates, and attributes created within other tests or by the create_sandbox.py script. If these structures are not in place ahead of time, the tests will not function as intended and the API requests will likely return a 404 error

  • To run a single file, open the test file you wish to run: e.g. .\test_batch.py

  • In the terminal, navigate to the test files and use the following command to run all the tests: python .\run_all_tests.py or to run a test individually: python .\test_batch_call.py

System Configuration

In order to run this sample, you must configure PI Web API with the proper security to:

  • Create an AF database
  • Create AF categories
  • Create AF templates
  • Create AF elements with attributes
  • Create PI Points associated with element attributes
  • Write and read element attributes
  • Delete all the above AF/PI Data Archive objects

In addition, PI Web API must be configured to allow CORS as follows:

Attribute Value Type
CorsExposedHeaders Allow,Content-Encoding,Content-Length,Date,Location String
CorsHeaders * String
CorsMethods * String
CorsOrigins http://localhost:9876 String
CorsSupportsCredentials True Boolean
DisableWrites False Boolean

Functionality

This sample shows basic functionality of the PI Web API, not every feature. The sample is meant to show a basic sample application that uses the PI Web API to read and write data to a PI Data Archive and AF. Tests are also included to verify that the code is functioning as expected.

The functionality included with this sample includes(recommended order of execution):

  • Create an AF database
  • Create a category
  • Create an element template
  • Create an element and associate the element's attributes with PI tags where appropriate
  • Write a single value to the attribute
  • Write 100 values to an attribute
  • Perform a Batch (6 steps in 1 call) operation which includes:
    • Get the sample tag
    • Read the sample tag's snapshot value
    • Read the sample tag's last 10 recorded values
    • Write a value to the sample tag
    • Write 3 values to the sample tag
    • Read the last 10 recorded values from the sample tag only returning the value and timestamp
  • Return all the values over the last 2 days
  • Return timestamp and values over the last 2 days
  • Delete the element
  • Delete the element template
  • Delete the sample database

For the main PI Web API Samples landing page ReadMe
For the main PI System Samples landing page ReadMe
For the main AVEVA Samples landing page ReadMe