Siemens SINUMERIK 828D Function Manual page 316

F1: Travel to fixed stop
6.2 General functionality
Message to PLC:
IS DB31, ... DBX62.4 ("Activate travel to fixed stop")
The FXS selection command can only be used in systems with digital drives (VSA, HSA, HLA).
Following condition must be observed:
MD37060 $MA_FIXED_STOP_ACKN_MASK, Bit 0 = 0
Bit 0 = 1 (waiting for PLC acknowledgement) must not be set, otherwise, an interpolator stop would be required
to acknowledge the signal, interrupting the movement.
Deselect FXS[ ]=0:
The following signal interfaces are reset:
Message to PLC:
IS DB31, ... DBX62.4 ("Activate travel to fixed stop")
The machine data:
MD37060 $MA_FIXED_STOP_ACKN_MASK
must contain the value zero for signal deselection without motion stop.
Without ramp
The torque limit is changed without taking into account the ramp if:
• FXS is activated with (FXS[]=1), to make sure that the reduction is activated immediately (especially for
synchronized actions).
• The drive needs to be de-energized as quickly as possible in the event of a fault.
Selection of FXS with G64
In the machine data:
MD37060 $MA_FIXED_STOP_ACKN_MASK
Bit 0 must be = 0 (Do not wait for PLC-input signal "Enable travel to fixed stop"), since the selection of FXS may
not initiate a motion stop.
Modify the torque FXST
The clamping torque can already be modified when approaching the stop.
The torque limit FXST acts in addition to the acceleration limitation with ACC.
The new torque taking into account the ramp
(MD37012 $MA_FIXED_STOP_TORQUE_RAMP_TIME)
becomes active one interpolation cycle after the change in the drive.
A change of the effective torque can be checked by reading the synchronized action variable
$VA_TORQUE[axis].
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Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions