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How to create and write a simple complex type
28 Apr 2020 16:11 #8417
by RND
Replied by RND on topic How to create and write a simple complex type
It required two changes. Our problem was we had not tried them both at the same time in the right combination.
First, the string that describes the type of the variable had to be correct in both the constructor for myStructured Data and myGenericData (obviously
) . As you showed us, the correct type string was confirmed by examining the variable after we read it. We previously tried that correct type string many times, but without the second necessary change.
With the correct string we received an exception saying:That showed us we had another type mismatch so we changed the type argument in WriteValue. That was our main problem.
from:to:
It was easy to incorrectly assume that the type problem was a single issue associated just with the node descriptor string because we had tried the correct string so many times unsuccessfully. It was the second problem with the argument in typeof() that finally fixed it.
Unfortunately, we are now struggling with passing exactly the same object to a method call immediately after the successful write using the following additional snippet after the WriteValue in succession. The method call fails though using the same data, and endpoint used one line before. We are troubleshooting. We've tried TypeCode.Object and TypeCode.Empty and also not using TypeCodes at all, but get various exceptions. If we do the same method call approach with a double, instead of the complex object it works fine.
Strangely, the inner exception seems to say there is no valid endpoint, which seems odd because it was used the moment before in WriteValue()
First, the string that describes the type of the variable had to be correct in both the constructor for myStructured Data and myGenericData (obviously
) . As you showed us, the correct type string was confirmed by examining the variable after we read it. We previously tried that correct type string many times, but without the second necessary change.With the correct string we received an exception saying:
Exception thrown: 'OpcLabs.EasyOpc.UA.OperationModel.UAException' in OpcLabs.EasyOpcUA.dll
*** Failure: Object must implement IConvertible.
+ Attempting to change an object of type "OpcLabs.EasyOpc.UA.UAExtensionObject" to type "OpcLabs.BaseLib.DataTypeModel.StructuredDataType".
+ The client method called was 'WriteMultiple'.from:
client.WriteValue(endpointDescriptor, nodeDescriptor, myGenericData, typeof(StructuredDataType));client.WriteValue(endpointDescriptor, nodeDescriptor, myGenericData, typeof(UAGenericObject));It was easy to incorrectly assume that the type problem was a single issue associated just with the node descriptor string because we had tried the correct string so many times unsuccessfully. It was the second problem with the argument in typeof() that finally fixed it.
Unfortunately, we are now struggling with passing exactly the same object to a method call immediately after the successful write using the following additional snippet after the WriteValue in succession. The method call fails though using the same data, and endpoint used one line before. We are troubleshooting. We've tried TypeCode.Object and TypeCode.Empty and also not using TypeCodes at all, but get various exceptions. If we do the same method call approach with a double, instead of the complex object it works fine.
object[] inputs =
{
myGenericData,
0
};
TypeCode[] typeCodes =
{
TypeCode.Object,
TypeCode.UInt16
};
object[] outputs;
outputs = client.CallMethod(
endpointDescriptor,
"ns=4;s=OpcCommunication.OpcEffectLinear[1]",
"ns=4;s=OpcCommunication.OpcEffectLinear[1]#MoveAbsolute",
inputs,
typeCodes);Strangely, the inner exception seems to say there is no valid endpoint, which seems odd because it was used the moment before in WriteValue()
Exception thrown: 'OpcLabs.EasyOpc.UA.OperationModel.UAException' in OpcLabs.EasyOpcUA.dll
*** Failure: Invalid opc.tcp endpoint URL ("opc.tcp:/"): The Host must not be empty.
+ The client method called was 'CallMultipleMethods'.Please Log in or Create an account to join the conversation.
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