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21:01, EET
November 29, 2012
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Hi,
I am using Prosys OPC UA java SDK. In console client after connecting to OPC UA demo server at opc.tcp://demo.ascolab.com:4841, when i read the node-class attribute of a node, it gives me a numeric value like this “Value: 2”.
How can i know about the node-class attribute of that node with this value?
Is there a manual or document to interpret this value?
Same is the case with Datatype, Access-level, User-Access-level attributes.
Kindly help me out here, i am kinda stuck here.
Regards,
Shahzad
21:16, EET
December 21, 2011
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The attribute values are defined in the ‘Attributes’ class.
DataType is a NodeId. All standard NodeIds are defined in the Identifiers class. But it may be best to look up the respective DataType node, which you can get from UaCilent.getAddressSpace().getType() (you can cast the result to a UaDataType).
AccessLevel defines the enumeration the access level attributes – the integer value defines an EnumSet and there are respective methods to convert the integer to the EnumSet.
8:08, EET
December 21, 2011
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All the above mentioned classes (Attributes, Identifiers, AccessLevel) are in the org.opcfoundation.ua.core package.
11:33, EET
November 29, 2012
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Thank you very much, it helped a lot!
18:38, EET
November 29, 2012
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Jouni Aro said
The attribute values are defined in the ‘Attributes’ class.
DataType is a NodeId. All standard NodeIds are defined in the Identifiers class. But it may be best to look up the respective DataType node, which you can get from UaCilent.getAddressSpace().getType() (you can cast the result to a UaDataType).
AccessLevel defines the enumeration the access level attributes – the integer value defines an EnumSet and there are respective methods to convert the integer to the EnumSet.
Could you provide that methods to convert the integer value to EnumSet. I cannot find it in org.opcfoundation.ua.core package.
20:34, EET
December 21, 2011
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maahirx said
Jouni Aro said
The attribute values are defined in the ‘Attributes’ class.
DataType is a NodeId. All standard NodeIds are defined in the Identifiers class. But it may be best to look up the respective DataType node, which you can get from UaCilent.getAddressSpace().getType() (you can cast the result to a UaDataType).
AccessLevel defines the enumeration the access level attributes – the integer value defines an EnumSet and there are respective methods to convert the integer to the EnumSet.
Could you provide that methods to convert the integer value to EnumSet. I cannot find it in org.opcfoundation.ua.core package.
AccessLevel.getSet() – and AccessLevel.getMask() for the other direction.
22:47, EET
November 29, 2012
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Alright, i get it. But that is not enough. Let me put it that way:
During browsing address space, at one node i called a method to get all the attributes of that node using following code
DataValue[] value = null;
UnsignedInteger attributeId[];
attributeId={Attributes.NodeId,Attributes.NodeClass,Attributes.BrowseName,Attributes.DisplayName,Attributes.Description,Attributes.WriteMask,Attributes.UserWriteMask,
Attributes.IsAbstract,Attributes.Symmetric,Attributes.InverseName,Attributes.ContainsNoLoops,Attributes.EventNotifier,Attributes.Value,Attributes.DataType,Attributes.ValueRank,Attributes.ArrayDimensions,Attributes.AccessLevel,Attributes.UserAccessLevel,Attributes.MinimumSamplingInterval,Attributes.Historizing,Attributes.Executable,Attributes.UserExecutable};
value = client.readAttributes(node, attributeId);
Now in return it gives me the following values.(A loop prints all the values.null values are omitted)
0: NodeId ns=2;s=MyLevel
1: NodeClass 2
2: BrowseName 2:MyLevel
3: DisplayName (en) MyLevel
5: WriteMask 0
6: UserWriteMask 2097151
12: Value 38.0
13: DataType class org.opcfoundation.ua.builtintypes.DataValue
i=11
14: ValueRank -1
16: AccessLevel 7
17: UserAccessLevel 7
18: MinimumSamplingInterval -1.0
19: Historizing true
What i am asking is a method to convert that integer value to a string message or user understandable form. Like in Node class attribute,2 represent it is a variable node-class. I studied the OPC UA address space, but i cant interpret the other attributes like, DataType,UserWriteMask,ValueRank,AccessLevel,UserAccesLevel,
MinimumSamplingInterval. There is a lot variety of data types.
I think i made my point, i simply need a method or methods to convert these return values to a string or User readable form. And sorry for my explanation, it is pretty confusing!!
Regards:
Shahzad
8:34, EET
December 21, 2011
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Yes, that is a bit complicated. There are various enum types and some of the integers are just defined as constants.
Perhaps easiest is to use AddressSpace.getNode() and according to the actual type, convert the node to a specific type, e.g.
if (node instanceof UaVariable) {
UaVariable variable = ((UaVariable)node);
// Use the fields of UaVariable
}
// etc.
Otherwise you will need to convert each attribute by your own – we do not have a common conversion function for that.
Otherwise, you may also browse through the supported attributes for a node with
String attributeNameStr = AttributesUtil.toString(attributeId);
DataValue dataValue = node.readAttribute(attributeId);
// …
}
But you still get the pure values for each.
These classes will help in converting to strings if you go this route: WriteAccess, AccessLevel. ValueRanks contains the used constants but there is no string conversion defined.
15:54, EET
November 29, 2012
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Ok, Thanks a lot.
There is another question, can we save an object of a class of UaClient?
if yes, then what is the the appropriate way to save it?
I have searched many ways, but none of them work.
Please help me out here!
Regards:
Shahzad
8:03, EET
December 21, 2011
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UaClient is not serializable and there is not yet anything to help you there. We might add something in future, but now you must save it yourself by just copying the property values with your own code. Where do you want to save it?
9:53, EET
November 29, 2012
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We want save it either on Sq Lite Database or in Shared preferences. Once the connection is done and UaClient Object is created, we want to save the object so next time we don’t have to create the client. That is what we are thinking, but only if it is possible. That is why we asked.
10:50, EET
December 21, 2011
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OK. I was just curious, in regard to what we might be able to provide in future. But as said, at the moment we don’t have a solution to that.
21:04, EET
November 29, 2012
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Well thanks a lot!
5:36, EET
November 29, 2012
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Hello,
sorry to disturb you again, i want to show simulation and show a lay man the values changing in a server.
can you suggest me any software that will integrate with your Java SDK console server and show it on any HMI.
19:32, EET
December 21, 2011
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If you are looking for a GUI client, you can check our new OPC UA Java Client, which is available for downloads, although it’s still at beta development phase.
Or you can check UaExpert, from Unified Automation.
If you need to show the data in a Control Center, the best ones have an OPC UA client as well. All of them should have an OPC Client, in which case, you can use UaGateway to connect them to the OPC UA Server.
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