public async Task <ActionResult> VariableRead(string jstreeNode)
{
var node = OpcSessionHelper.GetNodeIdFromJsTreeNode(jstreeNode);
bool lastRetry = false;
while (true)
{
try
{
DataValueCollection values = null;
DiagnosticInfoCollection diagnosticInfos = null;
ReadValueIdCollection nodesToRead = new ReadValueIdCollection();
ReadValueId valueId = new ReadValueId();
valueId.NodeId = new NodeId(node);
valueId.AttributeId = Attributes.Value;
valueId.IndexRange = null;
valueId.DataEncoding = null;
nodesToRead.Add(valueId);
UpdateStatus($"Read OPC UA node: {valueId.NodeId}");
Session session = await OpcSessionHelper.Instance.GetSessionAsync(_application.ApplicationConfiguration, HttpContext.Session.Id, HttpContext.Session.GetString("EndpointUrl")).ConfigureAwait(false);
ResponseHeader responseHeader = session.Read(null, 0, TimestampsToReturn.Both, nodesToRead, out values, out diagnosticInfos);
string actionResult;
if (values.Count > 0)
{
actionResult = $"{{ \"value\": \"{values[0]}\", \"status\": \"{values[0].StatusCode}\", \"sourceTimestamp\": \"{values[0].SourceTimestamp}\", \"serverTimestamp\": \"{values[0].ServerTimestamp}\" }}";
}
else
{
actionResult = string.Empty;
}
return(Content(actionResult));
}
catch (Exception ex)
{
OpcSessionHelper.Instance.Disconnect(HttpContext.Session.Id);
if (lastRetry)
{
return(Content(CreateOpcExceptionActionString(ex)));
}
lastRetry = true;
}
}
}
public async Task <ActionResult> GetChildren(string jstreeNode)
{
// This delimiter is used to allow the storing of the OPC UA parent node ID together with the OPC UA child node ID in jstree data structures and provide it as parameter to
// Ajax calls.
var node = OpcSessionHelper.GetNodeIdFromJsTreeNode(jstreeNode);
ReferenceDescriptionCollection references = null;
Byte[] continuationPoint;
var jsonTree = new List <object>();
// read the currently published nodes
Session session = null;
string endpointUrl = null;
try
{
UpdateStatus("Connecting to OPC Server");
session = await OpcSessionHelper.Instance.GetSessionAsync(_application.ApplicationConfiguration, HttpContext.Session.Id, HttpContext.Session.GetString("EndpointUrl")).ConfigureAwait(false);
endpointUrl = session.ConfiguredEndpoint.EndpointUrl.AbsoluteUri;
}
catch (Exception ex)
{
// do nothing, since we still want to show the tree
Trace.TraceError("Can not read published nodes for endpoint '{0}'.", endpointUrl);
Trace.TraceError(ex.Message);
}
bool lastRetry = false;
while (true)
{
try
{
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
try
{
if (session.Disposed)
{
session.Reconnect();
}
UpdateStatus($"Browse OPC UA node {node}");
session.Browse(
null,
null,
node,
0u,
BrowseDirection.Forward,
ReferenceTypeIds.HierarchicalReferences,
true,
0,
out continuationPoint,
out references);
}
catch (Exception ex)
{
Trace.TraceError("Can not browse node '{0}'", node);
Trace.TraceError(ex.Message);
}
Trace.TraceInformation("Browsing node '{0}' data took {0} ms", node.ToString(), stopwatch.ElapsedMilliseconds);
if (references != null)
{
var idList = new List <string>();
foreach (var nodeReference in references)
{
bool idFound = false;
foreach (var id in idList)
{
if (id == nodeReference.NodeId.ToString())
{
idFound = true;
}
}
if (idFound == true)
{
continue;
}
ReferenceDescriptionCollection childReferences = null;
Byte[] childContinuationPoint;
Trace.TraceInformation("Browse '{0}' count: {1}", nodeReference.NodeId, jsonTree.Count);
INode currentNode = null;
try
{
if (session.Disposed)
{
session.Reconnect();
}
UpdateStatus($"Browse OPC UA node {ExpandedNodeId.ToNodeId(nodeReference.NodeId, session.NamespaceUris)}");
session.Browse(
null,
null,
ExpandedNodeId.ToNodeId(nodeReference.NodeId, session.NamespaceUris),
0u,
BrowseDirection.Forward,
ReferenceTypeIds.HierarchicalReferences,
true,
0,
out childContinuationPoint,
out childReferences);
UpdateStatus($"Read OPC UA node {ExpandedNodeId.ToNodeId(nodeReference.NodeId, session.NamespaceUris)}");
currentNode = session.ReadNode(ExpandedNodeId.ToNodeId(nodeReference.NodeId, session.NamespaceUris));
}
catch (Exception ex)
{
Trace.TraceError("Can not browse or read node '{0}'", nodeReference.NodeId);
Trace.TraceError(ex.Message);
// skip this node
continue;
}
byte currentNodeAccessLevel = 0;
byte currentNodeEventNotifier = 0;
bool currentNodeExecutable = false;
VariableNode variableNode = currentNode as VariableNode;
if (variableNode != null)
{
currentNodeAccessLevel = variableNode.UserAccessLevel;
}
ObjectNode objectNode = currentNode as ObjectNode;
if (objectNode != null)
{
currentNodeEventNotifier = objectNode.EventNotifier;
}
ViewNode viewNode = currentNode as ViewNode;
if (viewNode != null)
{
currentNodeEventNotifier = viewNode.EventNotifier;
}
MethodNode methodNode = currentNode as MethodNode;
if (methodNode != null)
{
currentNodeExecutable = methodNode.UserExecutable;
}
jsonTree.Add(new
{
id = ("__" + node + OpcSessionHelper.Delimiter + nodeReference.NodeId.ToString()),
text = nodeReference.DisplayName.ToString() + " (ns=" + session.NamespaceUris.ToArray()[nodeReference.NodeId.NamespaceIndex] + ";" + nodeReference.NodeId.ToString() + ")",
nodeClass = nodeReference.NodeClass.ToString(),
accessLevel = currentNodeAccessLevel.ToString(),
eventNotifier = currentNodeEventNotifier.ToString(),
executable = currentNodeExecutable.ToString(),
children = (childReferences.Count == 0) ? false : true,
publishedNode = false
});
idList.Add(nodeReference.NodeId.ToString());
}
// If there are no children, then this is a call to read the properties of the node itself.
if (jsonTree.Count == 0)
{
INode currentNode = null;
try
{
currentNode = session.ReadNode(new NodeId(node));
}
catch (Exception ex)
{
Trace.TraceError("Can not read node '{0}'", new NodeId(node));
Trace.TraceError(ex.Message);
}
if (currentNode == null)
{
byte currentNodeAccessLevel = 0;
byte currentNodeEventNotifier = 0;
bool currentNodeExecutable = false;
VariableNode variableNode = currentNode as VariableNode;
if (variableNode != null)
{
currentNodeAccessLevel = variableNode.UserAccessLevel;
}
ObjectNode objectNode = currentNode as ObjectNode;
if (objectNode != null)
{
currentNodeEventNotifier = objectNode.EventNotifier;
}
ViewNode viewNode = currentNode as ViewNode;
if (viewNode != null)
{
currentNodeEventNotifier = viewNode.EventNotifier;
}
MethodNode methodNode = currentNode as MethodNode;
if (methodNode != null)
{
currentNodeExecutable = methodNode.UserExecutable;
}
jsonTree.Add(new
{
id = jstreeNode,
text = currentNode.DisplayName.ToString() + " (ns=" + session.NamespaceUris.ToArray()[currentNode.NodeId.NamespaceIndex] + ";" + currentNode.NodeId.ToString() + ")",
nodeClass = currentNode.NodeClass.ToString(),
accessLevel = currentNodeAccessLevel.ToString(),
eventNotifier = currentNodeEventNotifier.ToString(),
executable = currentNodeExecutable.ToString(),
children = false
});
}
}
}
stopwatch.Stop();
Trace.TraceInformation("Browsing all child infos of node '{0}' took {0} ms", node, stopwatch.ElapsedMilliseconds);
return(Json(jsonTree));
}
catch (Exception ex)
{
OpcSessionHelper.Instance.Disconnect(HttpContext.Session.Id);
if (lastRetry)
{
return(Content(CreateOpcExceptionActionString(ex)));
}
lastRetry = true;
}
}
}
