Setting up Servos on Ar 900 Wing

I’ve never worked with servos before as it’s my first fixed wing, and maybe digital are different to analog?

The servos that came with the PNP for the AR 900 had a total movement range of approximately 190*. These servos, EMAX ES08MD II, just keep rotating. This maybe normal, but all the setup videos etc I’ve seen say to find the mid movement position of the servo, and secure the horn in that posit.

If it’s normal, that’s fine, do I just secure the horn perpendicular to the wing, and that becomes the mid position?

Help much appreciated!