Siemens SINUMERIK 840D sl Function Manual page 313

Changing the status of the "Travel to fixed stop" function FXS does not change the status of
the "Force Control" function.
$AA_FOC
Value
Status of torque limiting
The actual status of the torque limiting can be read using system variable
$VA_TORQUE_AT_LIMIT.
$VA_TORQUE_AT_LIMIT
Value
Restrictions
the "Force Control" function has the following restrictions:
● The change of the torque/force limitation representing itself as an acceleration limitation is
only taken into account in the traversing movement at block limits (see command ACC).
● Only FOC: No monitoring is possible from the NC/PLC interface to check that the active
torque limit has been reached.
● If the acceleration limitation is not adapted accordingly, an increase in the following error
occurs during the traversing motion.
● If the acceleration limitation is not adapted accordingly, the end-of-block position is possibly
reached later than specified in:
MD36040 $MA_STANDSTILL_DELAY_TIME.
The machine data:
MD36042 $MA_FOC_STANDSTILL_DELAY_TIME
is introduced for this and monitored in this status.
Possible application for link and container axes
All axes that can be traversed in a channel, i.e. also link axes and container axes, can be
traversed to fixed stop.
References:
Function Manual, Extended Functions; Several Operator Panels on multiple NCUs, Distributed
Systems (B3)
The status of the machine axis is kept in the case of a container rotation, i.e. a clamped machine
axis remains at the stop.
If a modal torque limitation has been activated with FOCON, this is kept for the machine axis
even after a container rotation.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Meaning
0 FOC not active
1 FOC modal active
2 FOC non-modal active
Meaning
0 actually effective torque < torque limit value
1 actually effective torque == torque limit value
F1: Travel to fixed stop
6.2 Detailed description
313