Restore Synchronism Of Following Spindle - Siemens SINUMERIK 840D Function Manual

DB31, ... DBX31.4 = 0 → 1 (resynchronization)
If the programmed offset is restored (see Section "Restore synchronism of following spindle
(Page 875)").
Block search when synchronous operation is active
Note
When synchronous operation is active for a block search, then it is recommended that only
block search type 5, "Block search via program test" (SERUPRO), is used.
See also
S1: Spindles (Page 733)
19.4.2

Restore synchronism of following spindle

Causes for a positional offset
When the coupling is reactivated after the drive enable signals have been canceled, a
positional offset can occur between the leading and following spindles if follow-up mode is
activated. A positional offset can be caused by:
● A part has been clamped or both spindles have been turned manually (machine area is
open, drives are disconnected from supply).
● After the spindle enable signals are canceled, the two spindles coast to standstill at different
speeds if they are not mechanically coupled.
● A drive alarm occurs (internal follow-up mode):
DB31, ... DBX61.3 (follow-up mode active) = 1
When the alarm is cleared, the NC must not trigger any synchronization motion.
● A synchronization was not executed due to a synchronization lock of the following spindle:
DB31, ... DBX29.5 (Disable synchronization)
Basic procedure
If the following and leading spindles have fallen out of synchronism, or failed to synchronize at
all, synchronism can be restored between them by the following measures:
1. Set the axis enable signals and cancel synchronization disable signal if this has been set.
2. Start following spindle resynchronization with the NC/PLC interface signal:
DB31, ... DBX31.4 (resynchronization)
Only after the resynchronization process is complete can the setpoint-end synchronism be
fully restored.
3. Wait until the coupled spindles have synchronized.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
S3: Synchronous spindle
19.4 Special features
875