IOS socket編程 - NSStream不工作

我使用的是被稱爲具有IP地址的WiFly設備：169.254.1.1和端口2000年。我試圖連接到該設備通過iOS應用程序。我用下面的代碼連接：IOS socket編程 - NSStream不工作

CFReadStreamRef readStream; 
CFWriteStreamRef writeStream; 

UInt32 port = 2000; 
CFStringRef host = CFSTR("169.254.1.1"); 

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, host, port, &readStream, &writeStream); 

inputStream = (__bridge NSInputStream *)readStream; 
outputStream = (__bridge NSOutputStream *)writeStream; 

// set the delegates to this view controller 
[inputStream setDelegate:self]; 
[outputStream setDelegate:self]; 

// Set run loops to continuous receive information 
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 

// Finally, open the connection 
[inputStream open]; 
[outputStream open];

然後我用下面的處理流事件：

- (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent { 
    NSLog(@"stream event %i", streamEvent); 

    switch (streamEvent) { 

     case NSStreamEventOpenCompleted: 
      NSLog(@"Stream opened"); 
      break; 

     case NSStreamEventHasBytesAvailable: 
      if (theStream == inputStream) { 

       uint8_t buffer[1024]; 
       int len; 

       while ([inputStream hasBytesAvailable]) { 
        len = [inputStream read:buffer maxLength:sizeof(buffer)]; 
        if (len > 0) { 

         NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding]; 

         if (nil != output) { 
          NSLog(@"server said: %@", output); 
          [self messageReceived:output]; 
         } 
        } 
       } 
      } 
      break; 

     case NSStreamEventErrorOccurred: 
      NSLog(@"Can't connect to server"); 
      break; 

     case NSStreamEventEndEncountered: 
      [theStream close]; 
      [theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
      break; 

     default: 
      NSLog(@"Unknown event"); 
    }

所以，我可以看到，前兩個流被正確打開。然後立即跟蹤一個流事件4，從我的理解中可以預料到這一點。然而，我再嘗試調用一個函數：

- (IBAction)moveForward 
{ 
    NSLog(@"move forward called"); 
    NSString *response = [NSString stringWithFormat:@"2"]; 
    NSData *data = [[NSData alloc] initWithData:[response dataUsingEncoding:NSASCIIStringEncoding]]; 
    [outputStream write:[data bytes] maxLength:[data length]]; 
}

應當從一個Arduino UNO通過wifly返回「前進」。但是，當我點擊時，出於某種原因，我得到另一個NSStreamEvent 4。我還通過終端telnetted在將該設備與：