Siemens SINUMERIK 840D sl Function Manual page 367

2.2 Travel to fixed stop with analog drives
2.2.1 SIMODRIVE 611 digital (VSA/HSA)
Selection
The NC detects that the function "travel to fixed stop" is selected via the command
FXS[x]=1 and signals the PLC via the interface signal DB31, ... DBX62.4 ("Activate travel to
fixed stop") that the function has been selected.
If the machine data:
MD37050 FIXED_STOP_ACKN_MASK
is set correspondingly, the acknowledgement of the PLC via the NST
DB 31, ... DBX3.1 ("Enable travel to fixed stop") is awaited.
and after that the function is started.
This acknowledgment is not required by the NC for digital drives.
The axis now traverses to the target position at the programmed velocity. At the same time,
the clamping torque (specified via FXST[x]) is transferred to the drive via the digital
interface, and this limits its effective torque. In addition, the acceleration is reduced
accordingly in the NC automatically acc. to FXST[x]).
Fixed stop reached
As soon as the axis reaches the fixed stop, the axial contour deviation increases.
If the threshold entered in the machine data:MD37030 FIXED_STOP_THRESHOLD is
exceeded or the NST signal DB31, ... DBX1.2 ("Sensor fixed stop") is set, the control system
detects that the fixed stop has been reached.
The NC will then delete the distance to go and will synchronize the position setpoint to the
current actual position value. The controller enabling command remains active.
Subsequently the NC triggers the NST DB31, ... DBX62.5 ("Fixed stop reached") on the
PLC.
If the machine data:
MD37060 FIXED_STOP_ACKN_MASK
is set correspondingly, the acknowledgement of the PLC via the NST DB31 is, ... DBX1.1
("Acknowledge fixed stop reached") is waited for.
This acknowledgment is not required by the NC for digital drives.
Then a block change is executed. The clamping torque continues to be applied.
Basic logic functions: Travel to fixed stop (F1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed Description
2.2 Travel to fixed stop with analog drives
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