Data Logging via Novatel GNSS


I have been trying to connect Novatel GNSS with NVIDIA PX2.
I can see the device is connected using the ‘lsusb’ command. However, when I run chmod 666 /dev/ttyACM0 or chmod 666 /dev/ttyUSB0 the error states not such file or directory.
Is it because my mouse and keyboard are also connected via same USB hub?
I have tested my device on my Ubuntu Laptop and it works fine.
Kindly advise.