[Said]

I would like to know if, for my case, it is impossible to have circular movements.

[Albert]

No, it is not possible to convert spiral movements to circular movements.

You should change the drilling approach to not use spiral movements.

[Said]

Could you explain to me what the following options are for? I couldn't find a description in the documentation. 
By changing these settings, can I achieve circular movements?

   

[Albert]

The radius tolerance to consider arc moves as helix allow you to control the tolerance to convert helix to arc movements.

You can increase this tolerance to generate an arc instead of an helix, however, I strongly recommend to keep this tolerance small if you want to keep path accuracy.

The split arcs tolerance will convert arcs into smaller linear movements.

[Said]

I can't understand why RoboDK is not able to generate spiral movements from a G-code file when it's possible in Roboguide with Move C.
       

[Albert]

I insist that a spiral movement is not the same as an arc movement.