Siemens SINUMERIK 840D sl Function Manual page 895

Application
"Spindle stop" can halt the synchronous spindle pair without offset since the servo loop
position control remains operative.
Example
When the protective door is opened with an active synchronous spindle coupling, the FS and
LS must be stopped without the coupling relationship being altered. This can be achieved by
applying IS "Spindle stop" to halt the FS and LS (IS "Axis/spindle stationary" (DB31, ...
DBX61.4) = 1). "Servo enable" can then be canceled for both spindles.
Delete S value (DB31, ... DBX16.7)
The S value programmed for the LS is deleted and the LS decelerated down to zero speed
via a ramp. The FS and LS continue to operate in synchronous mode.
On the other hand, IS "Delete S value" has no affect on the FS in synchronous operation.
Resynchronize spindle 1/2 (DB31, ... DBX16.4 and 16.5)
It is also possible to synchronize the spindle (LS) with its positioning measuring system when
it is operating in synchronous mode. It is however recommended that the leading spindle
only be re-synchronized when synchronous mode is not active.
Re-synchronization (DB31, ... DBX31.4)
If the following and leading spindles have fallen out of synchronism, or failed to synchronize
at all, the programmed offset can be restored using the following interface signal:
IS "Re-synchronization" (DB31, ... DBX31.4).
When the low-high edge of the VDI signal is detected, resynchronization is started for the
following spindle in question and acknowledged by the NC with the following interface signal
for the following spindle:
IS "Synchronization running" (DB31, ... DBX99.4) acknowledged for the following spindle.
Traverse keys for JOG (DB31, ... DBX4.6 and 4.7)
The "plus and minus traversing keys" for JOG are not disabled in the control for the FS in
synchronous operation, i.e. the FS executes a superimposed motion if one of these keys is
pressed.
Note
If superimposed traversing movements are to be precluded, they must be locked out by
measures in the PLC user program.
NC Stop axes plus spindles (DB21, ... DBX7.4)
"NC Stop axes plus spindles" in synchronous operation decelerates the coupled spindles in
accordance with the selected dynamic response. They continue to operate in synchronous
mode.
Extended Functions
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Synchronous Spindles (S3)
14.4 Special features of synchronous mode
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