UAEndpointDescriptor endpointDescriptor = "opc.tcp://localhost:49320"; // Following code returns an error and fails to write specific index values of a float array type // var writeAttributeArguments = new UAWriteValueArguments(endpointDescriptor, nodeElementCollection[3].NodeId, new float[] { 7.7F, 8.8F, 9.9F }) { IndexRangeList = UAIndexRangeList.OneDimension(2, 4), }; var writeResponses = client.WriteMultipleValues(new UAWriteValueArguments[] { writeAttributeArguments}); // Write response values // Write result : False, // ErrorId : Opc.UA.ServiceResult=0x80730000, // ErrorMessage : OPC UA service result - {BadWriteNotSupported}. The server does not support writing the combination of value, status and timestamps provided. A list of parts provided (or not provided) to the Write service follows. // Value: yes, index range: yes, source timestamp: no, server timestamp: no. // Following code for read multiple values work with read of specific indexes of a float array type // var attributeArguments = new UAReadArguments(endpointDescriptor, nodeElementCollection[3].NodeId) { IndexRangeList = UAIndexRangeList.OneDimension(2,4), }; var readResponse = client.ReadMultipleValues(new UAReadArguments[] { attributeArguments});