Minimum NC-Cycle time for good interpolation

[Plc_User]

We will be using CtrlX drives with a Beckhoff controller for servo motion control.
The drives will be in CSP mode, so only command position will be sent to the drive.
On the one hand we want the bus cycle time as high as possible, because then we have a lot of margin for the code execution in the Beckhoff controller (f.i. in a 5ms controller cycle you can run more code then in a 1 ms controller cycle). On the other hand we want that the motion of our servomotor follows perfectly the motion command from the controller. 
I suppose that very short point to point motions require a short bus cycle (nc-task), but how do you make the relation between your motion profiles and the minimum NC-Cycle time?

[Drives_Uwe · Accepted solution]

Usually one states that a motion profile following a more complicated curve (no simple triangle or trapecoidal curve in velocity) should be resolved in at least around 10 distinguished position set or position command value points. But be aware
- that our drive can use a cubic interpolation in between two set points (if using cyclic sync position mode (CSP mode))
  --> this means the NC cycle time doesn´t necessarily need to be too short.
- that for simple point to point movements one can use
   - either "Profile position mode"
    
    
   - or the so called Bosch Rexroth specific "Drive internal interpolation" mode
    
    
   and doesn´t need to take into account the NC cycle time at all as everything is calculated within the drive in a 0,25 ms position cycle time.