Diagnostics For Synchronism Correction - Siemens SINUMERIK 840D sl Function Manual

The correction value is incorporated into the setpoint value calculation for the following
spindle, in the coupling module. Resetting the setpoint by the coupling offset relieves the
tension between the leading and following spindles.
The synchronism signals are produced by comparing the actual values with the corrected
setpoints. Once a correction process has been undertaken, the synchronism signals should
be present again:
DB31, ... DBX98.1 (coarse synchronism) and/or
DB31, ... DBX98.0 (fine synchronism)
The correction value can be implemented and the synchronism signals produced as well,
since the whole point of the "tracking the deviation from synchronism" function is to improve
synchronism when tension is present. When implementing this value, the accelerating power
is restricted to no more than 10% of the maximum acceleration and velocity.
When $AA_COUP_CORR[S<n>] has been implemented in full, the following NC/PLC
interface signal is set:
DB31, ... DBX99.2 (synchronism correction implemented)
This still applies even if $AA_COUP_CORR[S<n>] is zero and no correction needs to be
implemented.
When synchronism correction is complete, the NC/PLC interface signal DB31, ... DBX31.6
(track synchronism) must be reset to "0" in order to restore the rigidity of the coupling.
The correction value is not changed again once signal DB31, ... DBX31.6 has been reset or
once the coupling has been deactivated (with CPOF). The system variable
$AA_COUP_CORR[S<n>] then returns a constant value.
The correction value is taken into account until it is reset by setting system variable
$AA_COUP_CORR[S<n>] to "0", which must be done, at the very latest, once the workpiece
is removed from the spindle.
Note
The setpoint correction by means of the system variable $AA_COUP_CORR[S<n>] impacts
on all subsequent following spindle programming in the same way as a position offset, similar
to a DRF offset in the machine.
5.5.12.5

Diagnostics for synchronism correction

The current value of $AA_COUP_CORR (correction value for tracking the deviation in
synchronism) is displayed in the "Axis/Spindle Service" window, under the "Position offset for
the leading axis/spindle setpoint" line, for the purposes of diagnostics.
System variable $AA_COUP_CORR_DIST ($AA_COUP_CORR distance-to-go) can be used
to determine how much of the correction value is still be implemented.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
M3: Coupled axes
5.5 Generic coupling
331