CodeSys OPC UA client Unable to Connect To OPC UA sever through Username and password

kiranbsiddaiah — Thu, 07 May 2026 08:27:51 -0000

And also we do not have any opc ua related license . Do we need to have a opc ua license to communicate with OPC UA server with username and password

CodeSys OPC UA client Unable to Connect To OPC UA sever through Username and password

kiranbsiddaiah — Thu, 07 May 2026 03:08:24 -0000

Hi,

I'm using codesys v3.5 sp21 software. I have downloaded the sample opc ua client project from https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_uacapi_example.html and i tested connecting to "prosys opc ua simulation server".

Through Anonymous connection it is connecting to server and can read data.

Later tried to connect using username and password.
First got a SECURITY_CHECKS_FAILED error, trusted the client certificate in the server and this issue resolved.
Next got an INVALID_CERTIFICATE error, trusted the server certificate in the client and this issue resolved.
After these two error it is not establishing the connection and not giving any error messages.

UAAsyncProp: UA.AsyncProperty := (tnTaskName:='UAClientTask', usiTaskPrio:=20, udiTaskInterval:=10000);
UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_Aes128Sha256RsaOaep, eSecurity:=UA.SECURITY_MODE.SIGN_AND_ENCRYPT);
//UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_None, eSecurity:=UA.SECURITY_MODE.NONE);
UAAuth: UA.UserNameAuth := (sUserName:=UAVars.sUser, sPassword:=UAVars.sPass);
UAClient: UA.Client := (
itfAsyncProperty:= UAAsyncProp,
//sClientName:= 'MyOPC UA client name', //default: ‘CODESYS OPC UA Client’
sURL:= UAVars.sURL,
sSession:= UAVars.sSession,
itfPolicy:= UAPolicy,
itfAuth:=UAAuth,
udiTimeout:= 100000
//,itfNamespaceArray:= UAVars.itfNamespaceArray //optional use
);
-----------------------------------------------------------------------------------------------------------------------

Please let me know if any additional information required.

Thank you...

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