Ignition_SCADA_send_POST_request_simple_example.py

"""An example Ignition SCADA Gateway tag change event script that sends a simple JSON message to a flask
server when the production line starts and stops. The server runs alongside a tkinter window that
will shrink to a small semi-transparent button when the line starts running. The computer this runs
on was there for a reason, so obscuring the existing software was not an option. If there is an
unsaved defect record active in the window, it will pop back up when they stop so that they can update
it when finished.

When this was set up we hadn't gotten the WebDev module yet, so when the operator creates a new defect
record, by pushing the button, the available tag data is read directly from the Postgres/Timescale
database with the tag history using the psycopg2 library.

This is quite quick. The line start has a ~5 second delay while a line-starting signal goes off. So, the
fraction of a second delay is nothing.

Ignition SCADA version == 8.1.17
"""

if not initialChange:
    src_path = event.getTagPath().toString()  # tag path that triggered this event

    lam_num = Shared.L.get_num_from_path(src_path)  # get the production line number from the path

# ip address for the industrial PC with the flask server depends on the line number
flask_server_url = {1: '10.155.0.102', 2: '10.155.0.201'}[lam_num]  # static IP addresses!
defects_url = 'http://{}:5000/popup'.format(flask_server_url)  # the address for for the flask endpoint

hc = system.net.httpClient()  # this class can be used for POST and GET requests

# if the lam has started running, hide the popup
if newValue.getValue():  # boolean tags, so if the line is running, this is True
    param_dict = {"action": "shrink"}
else:
    param_dict = {"action": "show"}

result = hc.post(defects_url, params=param_dict).json