OpcUa Server how to get Client write event instead of change data event

[Dorammon]

count = 0
where True:
count += 1
time.sleep(1)

"count" is OpcUa server attribute, delay 1 second plus 1, I want get client write event in server instead of the data change event
i don't know how to do , i see the example code not found

[AndreasHeine]

you probably need to explain a little more what you want to do!
you want a callback if a value changes?

[AndreasHeine]

sadly there is no client write callback implemented!

Following the incomming request:

python-opcua/opcua/server/uaprocessor.py

Line 197 in 3012acf

elif typeid == ua.NodeId(ua.ObjectIds.WriteRequest_Encoding_DefaultBinary):

python-opcua/opcua/server/internal_server.py

Line 362 in 3012acf

def write(self, params):

python-opcua/opcua/server/address_space.py

Line 53 in 3012acf

def write(self, params, user=UserManager.User.Admin):

python-opcua/opcua/server/address_space.py

Line 662 in 3012acf

def set_attribute_value(self, nodeid, attr, value):

[Dorammon]

OK, thank you!

[AndreasHeine]

you could probably get away with storing the last value written from the server and compare it with the uavariable value if it is different its changed by the client (but the comparing needs to be inside a valuechange callback)

[Dorammon]

Sorry for your late reply

Is that what it means？
Sometimes this callback will not be detected

Can I judge in data change callback that it is written by the client?

[AndreasHeine]

no! i am talking about a valuecallback in the server not on clientside.