Siemens SINUMERIK 828D Programming Manual page 420

Supplementary commands
14.6 Travel to fixed stop (FXS, FXST, FXSW)
Further information
Rise ramp
A rate of rise ramp for the new torque limit can be defined in MD to prevent any abrupt
changes to the torque limit setting (e.g. insertion of a quill).
Alarm suppression
The fixed stop alarm can be suppressed for applications by the part program by masking the
alarm in a machine data item and activating the new MD setting with NEW_CONF.
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 ($R1) occurs and travel to fixed stop is not yet running,
activated for axis Y. The torque must correspond to 10% of the rated torque value. The width
of the monitoring window is set to the default.
Program code
N10 IDS=1 WHENEVER (($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
● Fixed stop monitoring is activated within the specified window width.
420
constant.
and then remains
FXSW
Programming Manual, 07/2010, 6FC5398-1BP40-0BA0
should be
FXS
Fundamentals