public void SubscribeInformation(STATIONNAME StationName, DEVICENAME DeviceName, dynamic FieldName) { ServerCallBack ClientCallBack = OperationContext.Current.GetCallbackChannel <ServerCallBack>(); OperationContext Context = OperationContext.Current; AstroData.SubscribeInformation(StationName, DeviceName, FieldName, Context.SessionId, ClientCallBack); }