I have been using a TRENDnet TU-S9 USB to serial adapter for a couple years.
When I upgraded OSX from 10.10 Yosemite to 10.11 El Capitan, it stopped working.
I've tried reinstalling the driver, but that did not fix it.
I ran ioreg -p IOUSB
and could still see the device, which is a good sign.
...
+-o USB-Serial Controller D@14200000 <class AppleUSBDevice, id 0x100000533, registered, matched, active, busy 0 (6 ms), retain 11>
...
Unfortunately /dev
does not contain tty.usbserial
when my adapter is connected.
How do I get OSX to create /dev/tty.usbserial
when I connect my adapter?