Can not create a client connection to my server?

[FrictionalUnemployment]

Hi, I'm trying to establish a connection with my OPCUA server. It's a OPCDA -> OPCUA converter, it seems to be handling the conversion quite well and there's no issues at all with it running when I am debugging it. However, when I try to establish a Client connection on OPC Expert for example it can not find the server and I have tried so many variations without luck. I am hoping to see if any of you know the issue here. Thanks beforehand if you decide to help me out!

#!/usr/bin/env python
# Credits to http://courses.compute.dtu.dk/02619/software/opcda_to_opcua.py
# Helped with the conversion of OPCDA to OPCUA

import sys
import asyncio
import OpenOPC
import decimal
import time
import pywintypes
from datetime import datetime
from asyncua import ua, Server, uamethod
from zeroconf import ServiceInfo, Zeroconf
import socket

# local imports
import announce_service as sa

pywintypes.datetime = pywintypes.TimeType

UA_URI = 'https://hv.se'
OPCDA_SERVER_STRING = ""
readable_variables = {}
writeable_variables = {}
tree = {}
obj_in_node = {}


# Constants
ITEM_ACCESS_RIGHTS = 5
ACCESS_READ = 0
ACCESS_WRITE = 1
ACCESS_READ_WRITE = 2
ITEM_VALUE = 2


class SubHandler(object):
    """
    Subscription handler to receive events from the server.
    """

    def __init__(self, n, opcda_string):
        self.i = 0
        self.opcda_string = opcda_string
        self.n = n

    async def final_datachange_notification(self, node, val, data):
        # Get a list containing root, objects, opc da server
        p_a_string = await node.get_path(as_string=True)
        print(p_a_string)
        #print(da.servers()[0])
        da_address = '.'.join([a.split(':')[1] for a in p_a_string[3:]])

        da = OpenOPC.client()

        da.connect(self.opcda_string)
        print('Datachanged ', da_address, val)
        da.write((da_address, val,))
        da.close()

    def datachange_notification(self, node, val, data):
        self.i = self.i + 1

        if(self.i == self.n):
            self.datachange_notification = self.final_datachange_notification

def read_value(value):
    value = value[0]
    if isinstance(value,decimal.Decimal):
        value = float(value)
    elif isinstance(value,list):
        if len(value) == 0:
            value = None
    elif isinstance(value,tuple):
        if len(value) == 0:
            value = None

    return value
    
async def sort_nodes_list(list, idx, root, da):
    
    for node in list:
        parts = node.split('.') #We split it into parts to separate each "part"
        folders = parts[:-1] # The first part is the folder, typically multiple ones
        file = parts[-1]  #Then we have the file that is in the folder
        for i, folder in enumerate(folders,1):
            if i == 1:
                parent = root
                
            else:
                parent = tree[path]
            path = '.'.join(folders[0:i])
            if path not in tree.keys():
                tree[path] = await parent.add_folder(idx, folder)
        
        for id, description_of_id, value in da.properties(node):
            if id is ITEM_ACCESS_RIGHTS:
                if value == 'Read':
                    value = ACCESS_READ
                elif value == 'Write':
                    value = ACCESS_WRITE
                elif value == 'Read/Write':
                    value = ACCESS_READ_WRITE 
            obj_in_node[id] = value
        curr_value = read_value((obj_in_node[ITEM_VALUE],))
        if type(curr_value) != int:
            curr_value = 0
        
        opcua_node = await tree[path].add_variable(idx, file, ua.Variant(curr_value, ua.VariantType.UInt16))
    
        if obj_in_node[ITEM_ACCESS_RIGHTS] in [ACCESS_READ]:
            readable_variables[node] = opcua_node
            # print(opcua_node)
        if obj_in_node[ITEM_ACCESS_RIGHTS] in [ACCESS_WRITE, ACCESS_READ_WRITE]:
            await opcua_node.set_writable()        
            writeable_variables[node] = opcua_node
            # print(opcua_node)


async def main():

    # We connect to the OPC-DA server (I assume there will only be one, else this will have to be changed)
    # We can also check if there is a server and if there isn't one we'll run only an OPC UA server without conversion
    da = OpenOPC.client()
    OPCDA_SERVER_STRING = da.servers()[0]
    da.connect(OPCDA_SERVER_STRING) #Connect to the first server in the array
    print(OPCDA_SERVER_STRING)

    # Setup the server for UA
    server = Server()
    await server.init()
    server.set_endpoint("opc.tcp://0.0.0.0:55341")
    
    server.set_server_name("OPC UA-DA Server")

    idx = await server.register_namespace(UA_URI)
    root = await server.nodes.objects.add_object(idx,OPCDA_SERVER_STRING)
    
    # We want to find the OPC-DA server nodes in aliases
    nodes_list = da.list('*', recursive=True) #A list of dot-delimited strings
    await sort_nodes_list(nodes_list, idx, root, da)

    
    
    async with server: #Starting the server
            
        handler = SubHandler(len(writeable_variables), OPCDA_SERVER_STRING) #Subscribing to datachanges coming from the UA clients
        sub = await server.create_subscription(500, handler)
        await sub.subscribe_data_change(writeable_variables.values())
            # In Robotstudio all variables are writeable, so the readable variables are empty
            # This should be changed when tried in a real environment, so temporary for now
        readable_vars = list(writeable_variables.keys()) #readable_variables
            # print(readable_vars)
        while True:
            
            for i in da.read(readable_vars):
                print(i)
                da_id = i[0]
                var_handler = writeable_variables[da_id] # Due to change
                await var_handler.set_value(read_value(i[1:]))
            await asyncio.sleep(1)
        

  

if __name__ == "__main__":
    sa.start_service_announcement(device_name="_adda-server.", iport=55341)
    asyncio.run(main())
```

`

[AndreasHeine]

any log or error?

[FrictionalUnemployment]

No that's the issue, I fixed all the bugs because I thought that was the issue. Now when I run it there is no errors other than that I can not establish a connection to the server from my (Client). I have checked the examples and it's almost the same code, I've even ran the example servers to see if it's my firewall but they work fine but this one doesn't. It makes no sense, could it be the OPC DA Client connection that is interfering somehow?

[FrictionalUnemployment]

Let me paste the error for when I try to establish a connection, one second.

[FrictionalUnemployment]

I want to apologize, so when I ran it again it started working. Super weird, do not know why it's working all of a sudden. I'll mark this as answered, the code above is free for anyone to use for their async servers. It will convert OPC DA <-> OPC UA, very useful for ABB Robots.

[AndreasHeine]

you should activate the logger in debug mode!

[FrictionalUnemployment]

you should activate the logger in debug mode!

I have forgotten about that, thank you. Next time this issue is brought up I'll use it, still pretty weird why I couldn't create a connection.