/// <summary>
/// Create the publisher data structures to manage OPC sessions, subscriptions and monitored items.
/// </summary>
/// <returns></returns>
public async Task <bool> CreateOpcPublishingDataAsync()
{
// create a list to manage sessions, subscriptions and monitored items.
try
{
await PublisherNodeConfigurationSemaphore.WaitAsync().ConfigureAwait(false);
await OpcSessionsListSemaphore.WaitAsync().ConfigureAwait(false);
var uniqueEndpointUrls = _nodePublishingConfiguration.Select(n => n.EndpointUrl).Distinct();
foreach (var endpointUrl in uniqueEndpointUrls)
{
var currentNodePublishingConfiguration = _nodePublishingConfiguration.First(n => n.EndpointUrl == endpointUrl);
EncryptedNetworkCredential encryptedAuthCredential = null;
if (currentNodePublishingConfiguration.OpcAuthenticationMode == OpcAuthenticationMode.UsernamePassword)
{
if (currentNodePublishingConfiguration.EncryptedAuthCredential == null)
{
throw new NullReferenceException($"Could not retrieve credentials to authenticate to the server. Please check if 'OpcAuthenticationUsername' and 'OpcAuthenticationPassword' are set in configuration.");
}
encryptedAuthCredential = currentNodePublishingConfiguration.EncryptedAuthCredential;
}
// create new session info.
OpcUaSessionManager opcSession = new OpcUaSessionManager(endpointUrl, currentNodePublishingConfiguration.UseSecurity, OpcSessionCreationTimeout, currentNodePublishingConfiguration.OpcAuthenticationMode, encryptedAuthCredential);
// create a subscription for each distinct publishing inverval
var nodesDistinctPublishingInterval = _nodePublishingConfiguration.Where(n => n.EndpointUrl.Equals(endpointUrl, StringComparison.OrdinalIgnoreCase)).Select(c => c.OpcPublishingInterval).Distinct();
foreach (var nodeDistinctPublishingInterval in nodesDistinctPublishingInterval)
{
// create a subscription for the publishing interval and add it to the session.
OpcUaSubscriptionManager opcSubscription = new OpcUaSubscriptionManager(nodeDistinctPublishingInterval);
// add all nodes with this OPC publishing interval to this subscription.
var nodesWithSamePublishingInterval = _nodePublishingConfiguration.Where(n => n.EndpointUrl.Equals(endpointUrl, StringComparison.OrdinalIgnoreCase)).Where(n => n.OpcPublishingInterval == nodeDistinctPublishingInterval);
foreach (var nodeInfo in nodesWithSamePublishingInterval)
{
// differentiate if NodeId or ExpandedNodeId format is used
if (nodeInfo.ExpandedNodeId != null)
{
// create a monitored item for the node, we do not have the namespace index without a connected session.
// so request a namespace update.
OpcUaMonitoredItemManager opcMonitoredItem = new OpcUaMonitoredItemManager(nodeInfo.ExpandedNodeId, opcSession.EndpointUrl,
nodeInfo.OpcSamplingInterval, nodeInfo.DisplayName, nodeInfo.HeartbeatInterval, nodeInfo.SkipFirst);
opcSubscription.OpcMonitoredItems.Add(opcMonitoredItem);
Interlocked.Increment(ref NodeConfigVersion);
}
else if (nodeInfo.NodeId != null)
{
// create a monitored item for the node with the configured or default sampling interval
OpcUaMonitoredItemManager opcMonitoredItem = new OpcUaMonitoredItemManager(nodeInfo.NodeId, opcSession.EndpointUrl,
nodeInfo.OpcSamplingInterval, nodeInfo.DisplayName, nodeInfo.HeartbeatInterval, nodeInfo.SkipFirst);
opcSubscription.OpcMonitoredItems.Add(opcMonitoredItem);
Interlocked.Increment(ref NodeConfigVersion);
}
else
{
Logger.Error($"Node {nodeInfo.OriginalId} has an invalid format. Skipping...");
}
}
// add subscription to session.
opcSession.OpcSubscriptions.Add(opcSubscription);
}
// add session.
OpcSessions.Add(opcSession);
}
}
catch (Exception e)
{
Logger.Fatal(e, "Creation of the internal OPC data managment structures failed. Exiting...");
return(false);
}
finally
{
OpcSessionsListSemaphore.Release();
PublisherNodeConfigurationSemaphore.Release();
}
return(true);
}
public virtual OpcUaSessionManager CreateOpcSession(string endpointUrl, bool useSecurity, uint sessionTimeout, OpcAuthenticationMode opcAuthenticationMode, EncryptedNetworkCredential encryptedAuthCredential)
{
return(new OpcUaSessionManager(endpointUrl, _nodePublishingConfiguration.First(n => n.EndpointUrl == endpointUrl).UseSecurity, OpcSessionCreationTimeout, opcAuthenticationMode, encryptedAuthCredential));
}