A few Celestron USB users on Mac OS X have struggled to have their USB-to-Mini USB cables recognized by OS X; that the USB option is not available in Telescope Connection Settings when connected to the scope via the cable. One possible solution is to install the driver found here:
Download File: PL2303_MacOSX_1.6.1_20160309.zip
Linked from here: http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=229&pcid=41
The file referenced is for a Serial to USB on old MacOS operating systems