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import asyncio |
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import logging |
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from asyncua import Client |
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logging.basicConfig(level=logging.INFO) |
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_logger = logging.getLogger(__name__) |
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class SubHandler: |
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""" |
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Subscription Handler. To receive events from server for a subscription |
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data_change and event methods are called directly from receiving thread. |
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Do not do expensive, slow or network operation there. Create another |
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thread if you need to do such a thing |
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""" |
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def event_notification(self, event): |
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_logger.info("New event received: %r", event) |
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async def main(): |
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url = "opc.tcp://localhost:4840/freeopcua/server/" |
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# url = "opc.tcp://admin@localhost:4840/freeopcua/server/" #connect using a user |
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async with Client(url=url) as client: |
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# Client has a few methods to get proxy to UA nodes that should always be in address space such as Root or Objects |
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_logger.info("Objects node is: %r", client.nodes.root) |
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# Now getting a variable node using its browse path |
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obj = await client.nodes.root.get_child(["0:Objects", "2:MyObject"]) |
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_logger.info("MyObject is: %r", obj) |
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myevent = await client.nodes.root.get_child(["0:Types", "0:EventTypes", "0:BaseEventType", "2:MyFirstEvent"]) |
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_logger.info("MyFirstEventType is: %r", myevent) |
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msclt = SubHandler() |
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sub = await client.create_subscription(100, msclt) |
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handle = await sub.subscribe_events(obj, myevent) |
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await asyncio.sleep(10) |
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await sub.unsubscribe(handle) |
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await sub.delete() |
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if __name__ == "__main__": |
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asyncio.run(main()) |
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FreeOpcUa /
opcua-asyncio
