Screen error: must be connected to a terminal

Projects Interfacing w/ Software on the Computer
1

I have Uno connected via USB to my Mac (Yosemite).

I try to get sensor data to Mac.

This works in Terminal app:

screen /dev/cu.usbmodem14131 9600

I tried to run this in AppleScript Editor and it gives error "must be connected to a terminal":

do shell script "screen /dev/cu.usbmodem14131 9600"