Siemens SINUMERIK 840D sl Programming Manual page 520

Oscillation
11.2 Control oscillation via synchronized actions
Online evaluation of reversal point
If there is a main run variable coded with $$ on the right of the comparison, then the two
variables are evaluated and compared with one another continuously in the IPO cycle.
Note
Please refer to Section "Motion-synchronized actions" for more information.
Oscillation movement restarting
The purpose of this synchronized action is to continue the movement of the oscillation axis
on completion of the part infeed movement.
The following instructions are used subject to the above assumptions:
WHENEVER $AA_DTEPW[X]==0 DO $AA_OVR[Z]= 100
Whenever
equal to
then
Next partial infeed
When infeed is complete, a premature start of the next partial infeed must be inhibited.
A channel-specific marker ($AC_MARKER[Index]) is used for this purpose. It is enabled at
the end of the partial infeed (partial distance-to-go ≡ 0) and deleted when the axis leaves the
reversal area. The next infeed movement is then prevented by a synchronized action.
On the basis of the given assumptions, the following instructions apply for reversal point 1:
1. Set marker:
WHENEVER $AA_DTEPW[X] == 0 DO $AC_MARKER[1]=1
Whenever
equal to
then
2. Delete marker
WHENEVER $AA_IM[Z]<> $SA_OSCILL_RESERVE_POS1[Z] DO $AC_MARKER[1] =
0
Whenever
greater or less than
then
3. Inhibit infeed
WHENEVER $AC_MARKER[1]==1 DO $AA_OVR[X]=0
Whenever
equal to
then
11-12
the distance-to-go for the partial infeed on infeed axis X in the WCS
is zero,
Set the axial override of the oscillation axis to 100%.
the distance-to-go for the partial infeed on infeed axis X in the WCS
is zero,
set the marker with index 1 to 1.
the current position of oscillating axis Z in the MCS is
the position of reversal point 1
set marker 1 to 0.
marker 1 is
is
set the axial override of the infeed axis to 0%.
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
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