Diagnostics For Synchronism Correction - Siemens SINUMERIK 840D 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.
14.5.13.5

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.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
M3: Coupled axes
14.5 Generic coupling
563