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Expected UA calls when a Read is performed
14 Jun 2014 09:23 #2044
by support
Replied by support on topic Expected UA calls when a Read is performed
Here is a capture from UA CTT when a single Read is made using EasyUAClient:
The first 3 calls should always be teher:
- GetEndpoints
- CreateSession
- ActivateSession
The next set of 3 Read-s is not related to what your app is doing - it is the client obtaining the basic information from the server it needs to operate.
The Publish and CreateMonitoredItems calls, in this case (when you are not explicitly subscribing), are also not related to your app. This is for a house-keeping subscription that is made automatically by the EasyUAClient to monitor the server status.
The TranslateBrowsePathsToNodeIds may or may not appear - it depends on whether the node was specified by using the browse path (as in my example), or directly by node it (in which case this call will not be present).
The OPC-UA call that actually performs the Read from the app is highlighted, and its details are in the right pane.
In case your client trace only has the GetEndpoints, I think that two possibilities exist:
1. The GetEndpoints failed, or no suitable endpoint was found by EasyUAClient. In this case you should get an error/exception.
2. Something got wrong between UA CTT and the client, and the GetEndpoints redirected the client to an endpoint that does NOT go through CTT, and therefore the rest of the communication had not been captured. If I remember well, CTT is supposed to modify the endpoints accordingly, but maybe you need to instruct it to run the appropriate script first.
Best regards
The first 3 calls should always be teher:
- GetEndpoints
- CreateSession
- ActivateSession
The next set of 3 Read-s is not related to what your app is doing - it is the client obtaining the basic information from the server it needs to operate.
The Publish and CreateMonitoredItems calls, in this case (when you are not explicitly subscribing), are also not related to your app. This is for a house-keeping subscription that is made automatically by the EasyUAClient to monitor the server status.
The TranslateBrowsePathsToNodeIds may or may not appear - it depends on whether the node was specified by using the browse path (as in my example), or directly by node it (in which case this call will not be present).
The OPC-UA call that actually performs the Read from the app is highlighted, and its details are in the right pane.
In case your client trace only has the GetEndpoints, I think that two possibilities exist:
1. The GetEndpoints failed, or no suitable endpoint was found by EasyUAClient. In this case you should get an error/exception.
2. Something got wrong between UA CTT and the client, and the GetEndpoints redirected the client to an endpoint that does NOT go through CTT, and therefore the rest of the communication had not been captured. If I remember well, CTT is supposed to modify the endpoints accordingly, but maybe you need to instruct it to run the appropriate script first.
Best regards
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