private void ReestablishConnection()
{
_logger.Trace();
_reconnectionHandler = new SessionReconnectHandler();
State = OpcState.Connecting;
_reconnectionHandler.BeginReconnect(_session, _config.ReconnectAttemptInterval, OnSessionReconnectComplete);
}
private void OnStateChanged(OpcState lastState)
{
_logger.Trace($"{lastState.ToString()}->{State.ToString()}");
OpcStateChanged?.Invoke(this, new OpcStateChangedEventArgs()
{
LastState = lastState, State = this.State
});
}
private void _session_KeepAlive(Session session, KeepAliveEventArgs e)
{
_logger.Trace();
if (e != null && e.Status != null)
{
if (!Object.ReferenceEquals(session, _session))
{
return;
}
if (ServiceResult.IsBad(e.Status))
{
_logger.Warn($"Connection to OPC server lost on keepalive interval");
State = OpcState.ConnectionLost;
_session.KeepAlive -= _session_KeepAlive;
ReestablishConnection();
}
}
}
public void CloseConnection()
{
try
{
_session?.Close();
_session?.Dispose();
_subscription.DeleteItems();
_subscription.Delete(true);
_subscription.Dispose();
}
catch (Exception e)
{
_logger.Warn($"Exception while closing connection to OPC server: {e.ToString()}");
}
finally
{
State = OpcState.Disconnected;
_session = null;
_subscription = null;
}
}
public async Task ConnectAsync(string url, string sessionName = "BreanosOpcConnectorSession")
{
_logger.Trace(ConnectorLogging.Process((nameof(url), url), (nameof(sessionName), sessionName)));
while (State != OpcState.Connected)
{
try
{
_session = await Session.Create(CreateConfig(), new ConfiguredEndpoint(null, new EndpointDescription(url)), true, sessionName, (uint)_config.SessionTimeout, null, null);
State = OpcState.Connected;
}
catch (Exception e)
{
_logger.Error($"Exception while creating a session with an OPC server: {e.ToString()}");
State = OpcState.Disconnected;
await Task.Delay(_config.ReconnectAttemptInterval);
}
}
_session.KeepAliveInterval = _config.KeepAliveInterval;
_session.KeepAlive += _session_KeepAlive;
_session.PublishError += _session_PublishError;
}
private void OnSessionReconnectComplete(object sender, EventArgs e)
{
_logger.Trace();
if (_reconnectionHandler == null)
{
_logger.Error($"ReconnectComplete called but reconnect handler was null");
State = OpcState.Disconnected;
return;
}
if (!Object.ReferenceEquals(sender, _reconnectionHandler))
{
_logger.Info($"Current reconnectHandler did not match the sender of this method");
return;
}
_session = _reconnectionHandler.Session;
_session.KeepAliveInterval = _config.KeepAliveInterval;
_session.KeepAlive += _session_KeepAlive;
_session.PublishError += _session_PublishError;
_reconnectionHandler.Dispose();
_reconnectionHandler = null;
State = OpcState.ConnectedAndListening;
}
