I have a USB-to-Serial Adapter that is being recognized on my Mac in the System Information as being connected to the USB Hub but when I run ls /dev in Terminal the usbserial is not showing up. It was working up until this morning but now it is not. I have tried rebooting, changing USB slots and the lot. Any suggestions?
So after doing some research I have found that the Prolific driver that is designed for the USB-to-Serial adapter is a little unstable. Therefore I used a third party driver that seems to have fixed the problem 100%. You can find it here, http://xbsd.nl/2011/07/pl2303-serial-usb-on-osx-lion.html, I recommend it even if the Prolific driver seems to be working okay.