Siemens SINUMERIK 840D sl Programming Manual page 559

Variant 3 only affects modulo following axes that are coupled to modulo leading axes. Time
optimization takes account of velocity limits of the following axis.
Description
Variant 1:
The positions of the leading axes and following axis at the instant the grouping is switched
on are stored as "Synchronized positions". The "Synchronized positions" can be read with
the system variable $AA_EG_SYN.
Variant 2:
If modulo axes are contained in the coupling group, their position values are modulus-
reduced. This ensures that the next possible synchronized position is approached (so-called
relative synchronization
approached if "Enable following axis override" interface signal DB(30 + axis number), DBX
26 bit 4 is issued for the following axis. If it is not issued, the program stops at the
EGONSYN block and self-clearing alarm 16771 is output until the above mentioned signal is
set.
Variant 3:
The tooth distance (deg.) is calculated like this: 360 * Zi/Ni. If the following axis is stopped at
the time of calling, path optimization returns responds identically to time optimization.
If the following axis is already in motion, NTGP will synchronize at the next tooth gap
irrespective of the current velocity of the following axis. If the following axis is already in
motion, NTGT will synchronize at the next tooth gap depending on the current velocity of the
following axis. The axis is also decelerated, if necessary.
Curve tables
If a curve table is used for one of the leading axes:
Ni
Zi
LAi
For more information about using curve tables and cascading and synchronizing electronic
gears, please refer to:
/FB3/ Function Manual Special Functions; Coupled Axes and ESR (M3), 'Coupled Motion
and Leading Value Coupling'.
Job planning
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
: e.g. the next tooth gap). The synchronized position is only
The denominator of the coupling factor for linear coupling must be set to
0. (Denominator 0 would be illegal for linear couplings.) Nominator zero
tells the control that
is the number of the curve table to use. The curve table with the specified
number must already be defined at POWER ON.
The leading axis specified corresponds to the one specified for coupling
via coupling factor (linear coupling).
Additional functions
13.6 Electronic gear (EG)
13-27