Ultrastudio sdi 9pin .cu & .tty missing from mac /dev folder

Hi,

I have been using ultrastudio thunderbolt express to capture and I am able to read from the
cu.RS422 DeckControl
listed in the /dev
to get the timecode

BUT

the ultrastudio sdi capture box via usb does not show a .cu instance in the /dev folder. Does anyone know where it is? or how i can make one show up in the /dev folder or a workaround?

thanks,
Derek

in otherwords... using the DeviceList example that comes with the sdk my ultrastudio thunderbolt prints out these attributes:
=============== UltraStudio Express ===============

Attribute list:
Serial port present: Yes
Serial port name: /dev/tty.RS422 Deck Control2
Device Persistent ID: Not Supported on this device
Device Topological ID: 3b0d00
Number of sub-devices: 1
Sub-device index: 0
Number of audio channels: 16
Input mode detection supported ? No
Full duplex operation supported ? No
Internal keying supported ? No
External keying supported ? No
HD-mode keying supported ? No
Device Interface Thunderbolt



THE KEY FOR ME IS THAT
" Serial port name: /dev/tty.RS422 Deck Control2 "
ATTRIBUTE.

BECAUSE... the ultrastudio SDI (via usb connection) seemingly throws an error... here's its printout from DeviceList:

=============== UltraStudio SDI ===============

Attribute list:
Serial port present: Yes
Could not query the serial port name attribute- result = 80000008
Device Persistent ID: Not Supported on this device
Device Topological ID: 14900000
Number of sub-devices: 1
Sub-device index: 0
Number of audio channels: 8
Input mode detection supported ? Yes
Full duplex operation supported ? No
Internal keying supported ? No
External keying supported ? No
HD-mode keying supported ? No
Device Interface: USB

Notice the serial port name attribute is missing and INSTEAD prints this:
"Could not query the serial port name attribute- result = 80000008"

IS this a bug? Intentional?

I am on a mac sierra 10.12.4 and using bmd desktop video setup 10.9

is the above a driver issue? does anyone know how i can get that serial port name attribute to get set???
thanks for any thoughts