Siemens SINUMERIK 840D sl Programming Manual page 404

Supplementary commands
14.6 Travel to fixed stop (FXS, FXST, FXSW)
Activating
The commands for travel to fixed stop can be called from synchronized actions or technology
cycles. They can be activated without initiation of a motion, the torque is limited
instantaneously. As soon as the axis is moved via a setpoint, the limit stop monitor is
activated.
Activation from synchronized actions
Example:
If the expected event ($R1) occurs and travel to fixed stop is not yet running, FXS should be
activated for axis Y. The torque must correspond to 10% of the rated torque value. The width
of the monitoring window is set to the default.
Program code
N10 IDS=1 WHENEVER (($R1=1) AND ($AA_FXS[Y]==0)) DO $R1=0 FXS[Y]=1 FXST[Y]=10
The normal part program must ensure that $R1 is set at the desired point in time.
Deactivation from synchronized actions
Example:
If an anticipated event ($R3) has occurred and the status "Limit stop contacted" (system
variable $AA_FXS) is reached, then FXS must be deselected.
Program code
IDS=4 WHENEVER (($R3==1) AND ($AA_FXS[Y]==1)) DO FXS[Y]=0 FA[Y]=1000 POS[Y]=0
Fixed stop reached
When the fixed stop has been reached:
• The distance-to-go is deleted and the position setpoint is corrected.
• The drive torque increases to the programmed limit value FXSW and then remains
constant.
• Fixed stop monitoring is activated within the specified window width.
404
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
Fundamentals