Moving a finger across the screen is showing characters when monitoring with cat.

First how it doesn't work:
I excpected the command
sudo cat /dev/ttyS4
to cause random characters to appear as an interpretation of the data stream when moving fingers across the screen. Instead I'm getting "Device or resource busy"

Not sure why, the touchscreen doesn't load as ttyS4, but using dmesg shows it is mounted at tty/ttys$/serio1/input/input4

What does work is
sudo cat /dev/input/event4

It works as far as showing random looking characters as a finger is drawn across the screen. However, the mouse pointer doesn't move. It's good to know that Ubuntu can see the touchscreen and data is being sent.

How do I finish configuring ubuntu for this device?