cdccontrol

cdccontrol is a command-line tool which can enable, disable and query the USB CDC drivers built into Mac OSX. If these drivers are enabled they prevent J-Link Commander from working. As the drivers load on demand, only when you have a device attached can you query to find out if they are actually loaded.

Usage: cdccontrol enable | disable | loaded 
    [ -v,--verbose ] 
    [ -V,--version ]

The arguments can be in any order and you can use either the single or double hyphen options interchangeably.

There must be one, and only one, command, either enable, disable or loaded

enable    - attempts to enable the drivers so you can use the UART connections of the board
disable   - attempts to disable the drivers so you can use J-Link Commander or nrfjprog to program it
loaded    - returns 0 when the drivers are currently not loaded 
            returns 1 when they are loaded
            returns something other than 0 or 1 on error

To show what cdccontrol is doing, specify verbose. If you want the version of the software, the version option will print it out and then immediately exit.

-v or --verbose    -    show a log of commands called by cdccontrol
-V or --version    -    print a version string and exit immediately