Siemens SINUMERIK 840D sl Function Manual page 922

Synchronous Spindles (S3)
Programming of synchronous spindle couplings
Read current angular offset
The current position offset between the FS and LS can be read in the NC part program by
means of the following axial system variables:
● Setpoint-based position offset between FS and LS:
● Actual-value-based position offset between FS and LS:
Example:
$AA_COUP_OFFS[S2]
If an angular offset is programmed with COUPON, this coincides with the value read after
reading the setpoint synchronization.
Reading the programmed angular offset
The position offset last programmed between the FS and LS can be read in the NC part
program by means of the following axial system variables:
$P_COUP_OFFS[<axial expression>]
Note
After cancellation of the servo enable signal when synchronous operation and follow-up
mode are active, the position offset applied when the controller is enabled again is different
to the originally programmed value.
$P_COUP_OFFS only returns the value originally programmed. $AA_COUP_OFFS and
$VA_COUP_OFFS return the current value. The programmed offset can be recreated with
NST DB31, ... DBX31.4 (re-synchronization).
14.2.4 Automatic selection and deselection of position control
Behavior in speed control mode
In DV coupling mode, program instructions COUPON, COUPONC and COUPOF, COUPOFS are
used to activate and/or deactivate position control for the leading spindle as required. If there
are several following spindles on the leading spindle, then in speed-controlled mode, the first
DV activates coupling position control for the leading spindle and the last DV coupling
deactivates coupling position control for the leading spindle if SPCON is not programmed.
The leading spindle does not need to be located in the same channel as the following
spindle.
922
$AA_COUP_OFFS[<axial expression>]
$VA_COUP_OFFS[<axial expression>]
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions