
B--63003EN--1/02
1. AXIS CONTROL
121
If a reference position return command is issued for a synchronous master
axis during synchronous control, it is executed normally for the master
axis, but the slave axis does not return to its reference position (the slave
axis only moves in synchronization with the reference position return of
the master axis) except for an automatic reference position return (G28)
issued when the master axis is in a parking state, in which case the amount
of movement is calculated so that the slave axis returns to its reference
position provided that a reference position return has been carried for the
slave axis. If more than one slave axis belongs to one master axis, a
reference position return command is executed so that the
lowest--numbered slave axis returns to its reference position. If the master
axis in one path is subjected to both synchronization with an axis in the
same path and synchronization with an axis in the other path
simultaneously, the lowest--numbered slave axis in the two paths is
moved to the reference position.
A return to the second (third or fourth) reference position by the G30
command works in the same way as G28. In other words, usually only
the master axis moves to the second (third or fourth) reference position.
If the master axis is parking, the lowest--numbered axis is caused to move
to its second (third or fourth) reference position.
If a reference position return check (G27) is specified during synchronous
control, the master and slave axes move to the specified position. Upon
completion of movement, a check is made to see whether the master axis
is at its reference position (no check is made for the salve axes) unless the
master axis is in a parking state, in which case a check is made upon
completion of positioning to see whether the lowest--numbered slave axis
is at its reference position.
The term synchronous control used here only refers to an operation in
which the same move command is issued to two different servo systems
at one time. Note that synchronous control does not involve
out--of--synchronization compensation, in which the positional deviation
between two servo motors is constantly checked and one of the servo
motors is subjected to compensation to reduce the deviation. However,
using parameter SERx (bit 1 of parameterNo. 8162) can specify detection
of out--of--synchronization.
If out--of--synchronization is detected, synchronous control is
immediately terminated, turning off the servo ready signal.
CAUTION
Out-- of--synchronization detection is not applied to
synchronous control within one path.
1.9.2.5
Reference position
return and its check
during synchronous
control
1.9.2.6
Out--of--synchronization
detection