Siemens SINUMERIK 840D Function Manual page 854

S3: Synchronous spindle
19.1 Brief description
Superimposed motion
In synchronous operation, the synchronous spindle copies the movement of the leading spindle
in accordance with the programmed transformation ratio.
At the same time, the synchronous spindle can also be traversed with overlay so that the LS
and FS can operate at a specific angular position in relation to one another.
The overlaid traversing movement of the FS can be initiated in various ways:
● Programmable position offset of FS for AUTOMATIC and MDA:
– The COUPON and SPOS language commands can be used for active synchronous
● Manual position offset of FS:
– In JOG (JOG continuous or JOG incremental) mode
– In AUTOMATIC and MDA modes
As soon as the FS executes the overlaid traversing movement, IS "Overlaid movement"
(DB31, ... DBX98.4) is set to the 1 signal.
The overlaid movement is executed optimally in terms of time at the maximum possible FS
speed with COUPON. With an offset change by means of SPOS, the positioning velocity can be
specified with FA[Sn] and manipulated by an override (can be selected through IS "Feedrate
override valid for spindle" DB31, ... DBX17.0).
Note
For more information about specifying the position speed with FA[Sn]:
Further information
Positioning mode (Page 739)
Setpoint correction
The setpoint correction of the system variable $AA_COUP_CORR[Sn] impacts on all
subsequent following spindle programming in the same way as a position offset and
corresponds to a DRF offset in the MCS.
Example: establish correction value
If a coupling offset of 7° has been programmed using COUPON(....,77) and if a mechanical
offset of 81° has come about as a result of closing the workpiece support fixture, a correction
value of 4° is calculated:
The system variables return the following values for the following spindle:
$P_COUP_OFFS[S2] ; programmed position offset = 77°
$AA_COUP_OFFS[S2] ; setpoint position offset = 77°
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operation to change the position reference between FS and LS (see Section "Selecting
synchronous mode for a part program (Page 856)").
Superimposition of FS using the handwheel or with plus or minus traversing keys when
synchronous operation is active.
Superimposition of FS with handwheel using DRF offset
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA