Q: We programs  the speed to 1200 or any value above 900 and the machine runs with 900 . With lower speeds it´s ok
A: This could be caused by any one of the below issues.
(1)   Please set the Speed parameter with a higher speed, if in your controller it is set “900”you cannot set a cutting speed above 900mm/min in the AUTO mode.

(2)   If in your NC program if you set speed in the nesting software as 900 you cannot set a speed above 900mm/min in AUTO mode. Either set the correct speed in the NC program or don’t set any speed in the nesting software then the controller will take the speed set in the controller.
You can DELETE the code “F900”in you NC program to remove the speed setting in the NC code.