Cannot send via serial port data from MAX/MSP to Arduino

hallo friends of MAX/MSP and arduino,

I cannot send data from MAX/MSP to arduino. The data will send from MAX but it will not arived in the monitor of arduino. Its a simple patch in MAX and a simple sketch in Arduino. Have anyone an idea about this problem?


Arduino 1.6.8

Yesterday I send data from MAX/MSP to Arduino but I don't now how it works. All things are the same: the MAX patch and the Arduino sketch, see the jpg. But today I have the same problem: I cannot send the data from MAX to Arduino. Can anyone help?

I can't see anywhere in the max sketch that chooses the serial port to use. So it might be a problem with your computer mapping the Arduino to a different COM port number. This would explain why it worked that one time.