Siemens SINUMERIK 840Di sl Programming Manual page 192

Motion commands
4.21 Travel to fixed stop (FXS, FXST, FXSW)
Combinability
Note
"Measure and delete distance-to-go" ("MEAS" command) and "Travel to fixed stop" cannot
be programmed in the same block.
Exception: One function acts on a path axis and the other on a positioning axis or both act
on positioning axes.
Contour monitoring
Contour monitoring is not performed while "Travel to fixed stop" is active.
Positioning axes
With "Travel to fixed stop" with POSA axes, the block change takes place independently of
the fixed stop movement.
Restrictions
Travel to fixed stop cannot be programmed
• for hanging axes (exception: possible on 840D with SIMODRIVE 611 digital),
• for gantry axes,
• for concurrent positioning axes, which are controlled exclusively by the PLC (FXS must
• If the torque limit is reduced too far, the axis will not be able to follow the specified
192
be selected from the NC program).
setpoint; the position controller then goes to the limit and the contour deviation increases.
In this operating state, an increase in the torque limit may result in sudden, jerky
movements.
To ensure that the axis can follow the setpoint, check the contour deviation to make sure
it is not greater than the deviation with an unlimited torque.
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals