decoding JoiningProcessIdentificationDataType|OPC UA Standard|Forum|OPC Foundation

Hi all,

when I'm trying to call AbortJoiningProcess, I cannot decode in the right way the bytes I receive in my instance of the server;

This seems a problem related that the codec register in my platform is not correct; I know that I'm going to decode the following structure:

Structures with optional fields

 or if I take the fragment in the NodeSet2.xml (for this this information model):

<UADataType NodeId="ns=1;i=3029" BrowseName="1:JoiningProcessIdentificationDataType">
<DisplayName>JoiningProcessIdentificationDataType</DisplayName>
<Description Locale="en">This structure contains the identification information of a Joining Process. It is used in set of methods defined in JoiningProcessManagementType.</Description>
<Category>IJT Abort Joining Process</Category>
<Category>IJT Start Selected Joining</Category>
<Category>IJT Select Joining Process</Category>
<Category>IJT Deselect Joining Process</Category>
<Category>IJT Reset Joining Process</Category>
<Category>IJT Increment Joining Process Counter</Category>
<Category>IJT Decrement Joining Process Counter</Category>
<Category>IJT Set Joining Process Size</Category>
<Category>IJT Start Joining Process</Category>
<Documentation>https://reference.opcfoundation.org/IJT/Base/v100/docs/10.21</Documentation>
<References>
<Reference ReferenceType="HasEncoding">ns=1;i=5121</Reference>
<Reference ReferenceType="HasEncoding">ns=1;i=5123</Reference>
<Reference ReferenceType="HasEncoding">ns=1;i=5122</Reference>
<Reference ReferenceType="HasSubtype" IsForward="false">i=22</Reference>
</References>
<Definition Name="1:JoiningProcessIdentificationDataType">
<Field Name="JoiningProcessId" DataType="TrimmedString" IsOptional="true">
<Description>It is the system-wide unique identifier of the joining process.</Description>
</Field>
<Field Name="JoiningProcessOriginId" DataType="TrimmedString" IsOptional="true">
<Description>It is an identifier to track the changes made to the original instance in the system.

Example: It can point to the identifier of the object when it was created for the first time. It should be an existing ID in the system if it is available else it can be NULL if it is not tracked in the system.</Description>
</Field>
<Field Name="SelectionName" DataType="TrimmedString" IsOptional="true">
<Description>It is the configured selection name of the joining process in the system.</Description>
</Field>
</Definition>
</UADataType>
<UAVariable NodeId="ns=1;i=6251" BrowseName="1:JoiningProcessIdentificationDataType" ParentNodeId="ns=1;i=6212" DataType="String">
<DisplayName>JoiningProcessIdentificationDataType</DisplayName>
<References>
<Reference ReferenceType="HasTypeDefinition">i=69</Reference>
<Reference ReferenceType="HasDescription" IsForward="false">ns=1;i=5121</Reference>
<Reference ReferenceType="HasComponent" IsForward="false">ns=1;i=6212</Reference>
</References>
<Value>
<uax:String xmlns:uax="https://opcfoundation.org/UA/2008/02/Types.xsd">JoiningProcessIdentificationDataType</uax:String>
</Value>
</UAVariable>
<UAVariable NodeId="ns=1;i=6252" BrowseName="1:JoiningProcessIdentificationDataType" ParentNodeId="ns=1;i=6214" DataType="String">
<DisplayName>JoiningProcessIdentificationDataType</DisplayName>
<References>
<Reference ReferenceType="HasTypeDefinition">i=69</Reference>
<Reference ReferenceType="HasDescription" IsForward="false">ns=1;i=5122</Reference>
<Reference ReferenceType="HasComponent" IsForward="false">ns=1;i=6214</Reference>
</References>
<Value>
<uax:String xmlns:uax="https://opcfoundation.org/UA/2008/02/Types.xsd">//xs:element[@name='JoiningProcessIdentificationDataType']</uax:String>
</Value>
</UAVariable>

Now the question are 2:

• How can I find out the codec that I need to store in my dictionary in order to decode in the right way (also having human readable data) what I receive when making a call with UaExpert
• Why there are 2 tag element namend UAVariable, and what is the useful for them?