opcua_actions.py

from opcua import Client
from opcua import ua
import time


class OpcuaClient:

    def __init__(self):
        self.client = None
        self.data = [("[size=14]16.02.2022", "[size=14]10", "[size=14]50", "[size=14]3", "[size=14]4", "[size=14]36", "[size=14]12", "[size=14]#F"),
                     ("[size=14]17.02.2022", "[size=14]11", "[size=14]53", "[size=14]5", "[size=14]3", "[size=14]26", "[size=14]12", "[size=14]#F")
                     ]

    def create_client(self, url):
        self.client = Client(url=url)
        self.client.connect()

    def add_data(self):
        """ Appends data to the self.data attribute """
        self.data.append(("[size=14]16.02.2022", "[size=14]10", "[size=14]50", "[size=14]3", "[size=14]4", "[size=14]36", "[size=14]12", "[size=14]#F"))

    def read_data(self, ns=4, i=6):
        """ reads data from client's node defined in the function and returns all the values as a list """
        node = self.client.get_node(f'ns={ns};i={i}')
        row = []
        for child in node.get_children():  # data is read in the order specified in the datablock
            row.append(child.get_value())
        row = [f"[size=14]{value}" for value in row]
        print(row)
        return tuple(row)

    def send_data(self, value, ns=4, i=4):
        """ Sends data to specified ns and i """
        variable = self.client.get_node(f'ns={ns};i={i}')
        dv = None
        if type(value) == float:
            dv = ua.DataValue(ua.Variant(value, ua.VariantType.Float))
        elif type(value) == bool:
            dv = ua.DataValue(ua.Variant(value, ua.VariantType.Boolean))
        elif type(value) == int:
            dv = ua.DataValue(ua.Variant(value, ua.VariantType.Int16))
        if dv:
            dv.ServerTimestamp = None
            dv.SourceTimestamp = None
            variable.set_value(dv)
        else:
            raise AttributeError

    def terminate_client(self):
        self.client.disconnect()