OPC UA Server and Client Simple Example

OPC Unified Architecture (OPC UA) is a machine to machine communication protocol for industrial automation developed by the OPC Foundation.

Below is the example code to exhange data between two machine in network.

As a example we are using python.

Create Test Server on Machine 1:

from opcua import Server
from random import randint
import datetime
import time


server = Server()

url = "opc.tcp://127.0.0.1:4840"
server.set_endpoint(url)

name = "OPC_SIMULATION_SERVER"
addspace = server.register_namespace(name)

node = server.get_objects_node()

Param = node.add_object(addspace, "Parameters")

Temp = Param.add_variable(addspace, "Temperature", 0)
Press = Param.add_variable(addspace, "Pressure", 0)
Time = Param.add_variable(addspace, "Time", 0)

Temp.set_writable()
Press.set_writable()
Time.set_writable()

 server.start()
 print("Server started at {}".format(url))

 while True:
    Temperature = randint(10,50)
    Pressure = randint(200, 999)
    TIME = datetime.datetime.now()

    print(Temperature, Pressure, TIME)

    Temp.set_value(Temperature)
    Press.set_value(Pressure)

    Time.set_value(TIME)

    time.sleep(0.1)

Create Test Client Machine 2:

from opcua import Client
import time

url = "opc.tcp://127.0.0.1:4840"

client = Client(url)

client.connect()
print("Client Connected")

while True:
           Temp = client.get_node("ns=2;i=2")
           Temperature = Temp.get_value()
           print(Temperature)

Download and Install OPC UA Client Free from Unified Automation Website ( https://www.unified-automation.com/downloads/opc-ua-clients.html ) to view Node ids.

Connect Machine 1 and Machine 2 with suitable network (e.g. Ethernet)

Start server and then run client

Client will print fetched data from Server.

That’s cool Testing is completed !

Also,

Example Code for OPC UA Client for KUKA OPC UA Server on Robot Controller:

Code has to run on client side(Laptop with Python installed).

Prerequisites:

1.OPC UA installed on KUKA Controller.

Install OPCUA using PIP install
PIP Install Cryptography

installOPC installCRYPT

Below code will connect with KUKA Controller OPC port > fetch data from node > Print Data (Here MyPos Variable from $config.dat)>Logs data to CSV file to specified path.

from opcua import Client
import time
import csv
print("Starting")

url = "opc.tcp://192.168.1.147:4840" # IP Address of KLI - KUKA

client = Client(url)

client.set_user("opcuaoperator")#Check username with KUKA OPC Documentation
                
client.set_password("kuka")#Check password with KUKA OPC Documentation

client.connect()


print("Client Connected to KUKA OPC Server")

X = client.get_node("ns=5;s=MotionDeviceSystem.ProcessData.R1.System.$config.MYPOS.X")
Y = client.get_node("ns=5;s=MotionDeviceSystem.ProcessData.R1.System.$config.MYPOS.Y")
Z = client.get_node("ns=5;s=MotionDeviceSystem.ProcessData.R1.System.$config.MYPOS.Z")  # $ACCU_STATE is battery state

Xx = str(X.get_value())
Yy = str(Y.get_value())
Zz = str(Z.get_value())
        
print("My Pos:" + "X : " + Xx + " Y: " + Yy + " Z: " + Zz)

temp = X.set_value(1200)
temp = Y.set_value(5)
temp = Z.set_value(1174)


 with myFile:
                         writer = csv.writer(myFile)
                         writer.writerows([now,now])
                         with open("E:/"filename".csv", "a") as log:
                             log.write("{0},{1}\n".format(now,str(Xx)))
                        
                        

See complete “KUKA OPC UA with GUI on Python” at https://github.com/pawankumargurav/kukaopcua 

OPC UA Server and Client Simple Example – Python