Siemens SINUMERIK 840D sl Function Manual page 900

Synchronous Spindles (S3)
Brief description
Synchronous spindle pair
Synchronous operation involves a following spindle (FS) and a leading spindle (LS), referred
to as the synchronous spindle pair. The following spindle imitates the movements of the
leading spindle when a coupling is active (synchronous operation) in accordance with the
defined functional interrelationship.
Synchronous mode
Synchronous mode (also referred to as "Synchronous spindle operation") is another spindle
operating mode. Before synchronous mode is activated, the following (slave) spindle must
have been switched to position control. Synchronous operation is activated for the following
spindle when the coupling is activated. As soon as the coupling is deactivated, the following
spindle switches to back to open-loop control mode.
As soon as synchronous operation is active for the following spindle, the following interface
signal is reported to the PLC:
NST "Synchronous operation" (DB31, ... DBX84.4) = 1.
Number of synchronous spindles
It is possible to couple several following spindles to one leading spindle. The number of
following spindles on this leading spindle depends on the respective versions of the
appropriate software versions.
Any number of following spindles in any channels of one NCU or a different NCU can be
coupled to this leading spindle.
Note that one spindle is always the master and the number of couplings results from the
number of axes less the master.
Options in synchronous mode
The following functions are available for synchronous mode:
● FS and LS turn at the same speed
● Rotation in the same or opposite direction between LS and FS
● Following and leading spindles rotate at different speeds
● Settable angular position between FS and LS (φ
● Activation of synchronous operation between LS and FS can take place when the
● The full functionality of the open-loop and position control modes is available for the
900
(n = n ; speed ratio k
FS LS
(can be defined positively or negatively using speed ratio k
(n = k · n ; speed ratio k
FS Ü LS
Application: Polygonal turning
The spindles run at synchronous speed with a defined angular offset between FS and LS
(position synchronous coupling).
Application: Shaped workpieces
spindles are in motion or at standstill.
leading spindle.
= 1)
Ü
≠ 1)
Ü
)
Ü
= φ + Δφ)
FS LS
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions