Not receiving event after subscribe

[Darkmagister]

Describe the bug
i've used the client-event example to subscribe to node to get the events, the only difference is that i didn't pass the event type when i use the subscribe_event

To Reproduce

sys.path.insert(0, "..")

try:
    from IPython import embed
except ImportError:
    import code

    def embed():
        vars = globals()
        vars.update(locals())
        shell = code.InteractiveConsole(vars)
        shell.interact()


from opcua import Client

from opcua.tools import uals

class SubHandler(object):

    """
    Subscription Handler. To receive events from server for a subscription
    data_change and event methods are called directly from receiving thread.
    Do not do expensive, slow or network operation there. Create another
    thread if you need to do such a thing
    """
    def event_notification(self, event):
        print("New event recived: ", event)


if __name__ == "__main__":

    client = Client("opc.tcp://192.168.0.5:8119/")
    try:
        client.connect()

        # Client has a few methods to get proxy to UA nodes that should always be in address space such as Root or Objects
        root = client.get_root_node()
        print("root node is: ", root)

        # Now getting a variable node using its browse path
        obj  = client.get_node('ns=2;s=Notification/Messages')
        print("Objects node is: ", obj)

        msclt = SubHandler()
        sub = client.create_subscription(100, msclt)
        handle = sub.subscribe_events(obj)

        embed()
        sub.unsubscribe(handle)
        sub.delete()
    finally:
        client.disconnect()

Expected behavior
wiev print New event recived: ... but getting nothing

Version
Python-Version:3.8.6
python-opcua Version (e.g. master branch, 0.9): 0.98.9

[AndreasHeine]

does it work with UAExpert? screenshot?

[Darkmagister]

does it work with UAExpert? screenshot?

yes in ua expert i can see the events, i don't know what kind of screenshot is usefull to you ...

also if i do the same with the opcua-client i subscribe to event of the same node i don't get anything

[AndreasHeine]

can you turn on the logger and look if there is any hint or issue according to the event?

[AndreasHeine]

you can also try to:

handle = sub.subscribe_events() # empty it uses server object so all events of the server

[Darkmagister]

can you turn on the logger and look if there is any hint or issue according to the event?

sorry but what do you me turn on logger ??

[Darkmagister]

you can also try to:

handle = sub.subscribe_events() # empty it uses server object so all events of the server

i only got this events:

New event recived:  Event(["EventId:b',\\xfb5\\x8cq\\xf4RE\\x9d\\x99\\x07&\\\\7\\xa7\\xb0'", 'EventType:FourByteNodeId(i=2071)', 'SourceNode:NumericNodeId(ns=7;i=1004304931)', 'SourceName:Pure Python Client Session1', 'Time:2022-12-14 10:42:01.518655', 'ReceiveTime:2022-12-14 10:42:01.518655', 'LocalTime:None', 'Message:LocalizedText(Encoding:3, Locale:en-US, Text:Session Pure Python Client Session1 created.)', 'Severity:300'])
New event recived:  Event(["EventId:b'\\xf3\\x9d\\xc2|\\xb4\\xeaEI\\x94\\xcfg\\xd2\\xc4\\x962;'", 'EventType:FourByteNodeId(i=2071)', 'SourceNode:NumericNodeId(ns=7;i=1004304987)', 'SourceName:Pure Python Client Session1', 'Time:2022-12-14 10:43:01.587090', 'ReceiveTime:2022-12-14 10:43:01.587090', 'LocalTime:None', 'Message:LocalizedText(Encoding:3, Locale:en-US, Text:Session Pure Python Client Session1 created.)', 'Severity:300'])
New event recived:  Event(["EventId:b'\\xc6\\xd5$.\\x9an\\x1fG\\xbf\\xf0n0\\x11\\xfc\\xd0\\x1c'", 'EventType:FourByteNodeId(i=2071)', 'SourceNode:NumericNodeId(ns=7;i=1004305043)', 'SourceName:Pure Python Client Session1', 'Time:2022-12-14 10:44:01.653526', 'ReceiveTime:2022-12-14 10:44:01.653526', 'LocalTime:None', 'Message:LocalizedText(Encoding:3, Locale:en-US, Text:Session Pure Python Client Session1 created.)', 'Severity:300'])
New event recived:  Event(["EventId:b'\\xbd\\x87\\xb6\\xc1\\x81\\xb56C\\x98]\\xb2\\x91\\x16\\x87\\x87\\n'", 'EventType:FourByteNodeId(i=2071)', 'SourceNode:NumericNodeId(ns=7;i=1004305099)', 'SourceName:Pure Python Client Session1', 'Time:2022-12-14 10:45:01.721962', 'ReceiveTime:2022-12-14 10:45:01.721962', 'LocalTime:None', 'Message:LocalizedText(Encoding:3, Locale:en-US, Text:Session Pure Python Client Session1 created.)', 'Severity:300'])

that are pretty strange to me as they seems from the client and not from the server ... but no event from the server

[AndreasHeine]

i made a few tests with your script against some demo-servers (Unified Automation Stack and node-opcua stack and it actually works...)

Unified Automation Stack (UaCppDemoServer):

node-opcua (opc.tcp://opcua.umati.app:4843):

Have you some additional information about the server!?

[Darkmagister]

i don't know a lot is a software from a cnc machine but i have very little to none information, a getting it it's quite difficult as they don't give a lot of info ...

[Darkmagister]

i made a few tests with your script against some demo-servers (Unified Automation Stack and node-opcua stack and it actually works...)

Unified Automation Stack (UaCppDemoServer):

node-opcua (opc.tcp://opcua.umati.app:4843):

Have you some additional information about the server!?

i've tried downloading the 1.7.7 cpp demo server from ua, but it doesn't work for me ... the only event i get if the python client session created ... i've never used the server demo is there something i have to do to generate an event ??

[AndreasHeine]

In the UaCpp server you need to trigger them!

or you can use a online server which has some demoevents implemented "opc.tcp://opcua.umati.app:4843"

[Darkmagister]

In the UaCpp server you need to trigger them!

or you can use a online server which has some demoevents implemented "opc.tcp://opcua.umati.app:4843"

thanks, same result here now i tried to contact them telling that i can see the event from the uademoserver but not from their and let's see if something happen, thanks a lot i will update

i've also updated the opcua lib to 0.98.13 but same result

[Darkmagister]

one little update is that i've tried using another library (while i'm waiting some useful info) node-opcua and that works ok, i receive the events normally

is there anything i can do to understand why is not working with this lib? any like debug option to get more info ? or any info from the node-opcua lib event that can be helpful? (i don't know if can be any useful but the node-opcua need to have endpointMustExist: false as the serve give localhost as endpoint)

[AndreasHeine]

that would take some time to find the issue! the main problem is to reproduce the behavior...

you could try opcua-asyncio (pip install asyncua) it the current active supported version and python-opcua is deprecated...

it has also a sync wrapper with very little api changes!

[Darkmagister]

that would take some time to find the issue! the main problem is to reproduce the behavior...

you could try opcua-asyncio (pip install asyncua) it the current active supported version and python-opcua is deprecated...

it has also a sync wrapper with very little api changes!

I tried with the other lib the Asyncio and same behavior as this one ... So if there is anything I could try to get debug info it would be awesome ... Otherwise I have to rede the communication part with another lib ... And that would take more time :)

[AndreasHeine]

@Darkmagister can you try this:

https://github.com/FreeOpcUa/opcua-asyncio/discussions/1164#discussioncomment-4599915

[Darkmagister]

@Darkmagister can you try this:

FreeOpcUa/opcua-asyncio#1164 (comment)

i tried using this: subscribe_alarms_and_conditions instead of subscribe_events

but still same result no event show up, i haven't set the type because i'm not sure what is the nodeid of the message type