Siemens CNC Milling | CT | Circle with Tangential Transition

CT Code Introduction

In Siemens CNC controller, with CT code and the programmed end point in the current plane G17 through G19, a circle is generated which is connected tangentially to the previous path segment (circle or straight line) in this plane.

This defines the radius and center point of the circle from the geometric relationships of the previous path section and the programmed circle end point.

See the following illustration for circle with tangential transition to the previous path section:

CT Code Example

N10 G1 X20 F300 ; Straight line
N20 CT X… Y… ; Circle with tangential connection