Reading a tool offset value|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

Hi,

After a successful connection to a machine Siemens Sinumerik 840-d, we are trying to read a tool offset value. Here is the minimal code:

// Connection to the machine
Session session = Session.Create(...);

// List of nodes to read
ReadValueIdCollection nodesToRead = new ReadValueIdCollection ();
string nodeId = "ns=2;s=/ToolCompensation/edgeData[u1,c2,1]"
var readValueId = new ReadValueId () { NodeId = nodeId, AttributeId = Attributes.Value, IndexRange = "" };
nodesToRead.Add (readValueId);

// Get the answer
session.Read (null, int.MaxValue, TimestampsToReturn.Both, nodesToRead, out DataValueCollection results, out DiagnosticInfoCollection diagnostics);
object answer = results[0].Value;

The variable "diagnostics" is null so it is good. But the problem we are facing is that the variable "answer" is also null. We are however sure that the node "/ToolCompensation/edgeData" exists and that the format to use is "/ToolCompensation/edgeData[u1,c {column number},{tool number}]", according to the Siemens specifications. We also tried different configurations like:

• /ToolCompensation/edgeData
• /ToolCompensation/edgeData[u1,1]
• /ToolCompensation/edgeData[1,1,1]

Does anyone know why we are receiving null values? Is it possible that while the address "/ToolCompensation/edgeData" is valid, values are really null?

Best regards,
Davy