Introduction

Marginal condition

A spindle can basically be operated in a position-controlled or a speed-controlled mode. In most cases, the mode is defined statically and, in the case of SERCOS drives, all parameters required for the respective mode must be configured in the drive telegram.

In the position-controlled mode, the maximum speed of SERCOS spindles is, however, limited to 180° per sampling cycle as otherwise the drive controller can no longer clearly determined the direction of rotation from the specified distance change. With a sampling cycle of 2 ms, this results in a maximum speed of 15,000 rpm, for example.

Functionality

To also enable higher speeds, in the event of pure speed programming the spindle is operated in the speed-controlled mode and, if a position is specified, it is operated in the position-controlled mode.

Changing over between the two modes can take place automatically during motion.

Changing over and switching back can be specified by means of corresponding parameters.

Introduction 1:
Introduction 2:

The drive must always support changing over between position and speed control.
Automatic changing over by the CNC is currently only available for SERCOS drives.

Programming example

%spindle-position 
N30 S200 M4 
N40 M19 S.POS=180 S1000 M4 
N50 S200 M3 
N60 M19 S.POS=180 S1000 M4 
N70 S200 M4 
N80 M19 S.POS=180 S1000 M3 
M30