The manufacturer used labview to operate this unit.
You should be able to read the commands issued via TCP in the LabView program and follow the same sequence using TCP in a Qt program.

The problem is not Qt, it is the commands you send to the device and the syntax they use. Surely the manufacturer has a manual for this device that explains how to control it.

But you have all of us guessing in the dark. You haven't told us anything about this device except that it is a "Pan Tilt unit". Who makes it? What model is it? What is the link to the manufacturer's web site?