Differential Speed Between Leading And Following Spindles - Siemens SINUMERIK 840D Function Manual

NC Start (DB21, ... DBX7.1)
(See Section "Response of the synchronous-spindle coupling for NC Start (Page 872)")
Note
NC Start after NC Stop does not deselect synchronous operation.
19.4.4

Differential speed between leading and following spindles

When does a differential speed occur?
A differential speed develops, e.g. with turning machine applications, when two spindles
oppose one other. Through the signed addition of two speed sources, a speed component is
derived from the leading spindle via the coupling factor. In addition to this, for the following
spindle a speed (S...) and a direction of rotation (M3/M4) can be programmed.
Generally, to achieve synchronous operation, a coupling factor is used with a value of '-1'. This
sign reversal then results in a differential speed for the following spindle as compared to an
additional programmed speed.
This typical behavior in relation to the NC is illustrated in the following diagram.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
S3: Synchronous spindle
19.4 Special features
881