Functional Sequence; Selection - Siemens SINUMERIK 840D sl Function Manual

F1: Travel to fixed stop
6.2 Detailed description
6.2.2

Functional sequence

6.2.2.1

Selection

Figure 6-1
Procedure
The NC detects that the function "Travel to fixed stop" is selected via the command
FXS[x]=1 and signals the PLC using the IS DB31, ... DBX62.4 ("Activate travel to fixed stop")
that the function has been selected.
If the machine data:
MD37060 $MA_FIXED_STOP_ACKN_MASK (monitoring PLC acknowledgements for travel
to fixed stop)
is set correspondingly, the system waits for the acknowledgement of the PLC using the IS
DB31, ... DBX3.1 ("Enable travel to fixed stop").
The programmed target position is then approached from the start position at the programmed
velocity. The fixed stop must be located between the start and target positions of the axis/
spindle. A programmed torque limit (clamping torque specified via FXST[<axis>]) is effective
from the start of the block, i.e. the fixed stop is also approached with reduced torque. Allowance
for this limitation is made in the NC through an automatic reduction in the acceleration rate.
If no torque has been programmed in the block or since the start of the program, then the value
is valid in the axis-specific machine data:
MD37010 $MA_FIXED_STOP_TORQUE_DEF (default for fixed stop clamping torque)
is entered.
296
Example of travel to fixed stop
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions