Siemens SINUMERIK 828D Function Manual page 306

F1: Travel to fixed stop
6.2 General functionality
Depending on the machine data:
MD37060 $MA_FIXED_STOP_ACKN_MASK
the acknowledgement of the PLC is awaited through resetting of the NST
DB31, ... DBX3.1 ("Enable travel to fixed stop") and/or
DB31, ... DBX1.1 ("Acknowledge fixed stop reached").
The axis will then change to position control. The follow­up mode of the position setpoints is ended and a
synchronization to the new actual position is carried out.
A programmed traverse motion can then be executed. This motion must lead away from the fixed stop or else the
stop or even the machine may sustain damage.
A block change is executed after the target position has been reached.
Multiple selection
A selection may only be carried out once. If the function is called once more due to faulty programming
(FXS[Axis]=1) the alarm 20092 "Travel to fixed stop still active" is initiated.
Block­related synchronized actions
By programming a block­related synchronized action, travel to fixed stop can be connected during an approach
motion.
Programming example:
N10 G0 G90 X0 Y0
N20 WHEN $AA_IW[X]>17 DO FXS[X]=1
N30 G1 F200 X100 Y110
Changing the clamping torque and fixed stop monitoring window
The clamping torque and the monitoring window can be changed with the commands FXST[x] and FXSW[x].
The changes take effect before traversing movements in the same block.
Programming of a new fixed stop monitoring window causes a change not only in the window width but also in
the reference point for the center of the window if the axis has moved prior to reprogramming. The actual position
of the machine axis when the window is changed is the new window center point.
Terminal EP (Enable Pulses) can be controlled using MD37002
With the machine data:
MD37002 $MA_FIXED_STOP_CONTROL
the response in the case of pulse inhibit at the stop is controlled.
Deleting the pulses using terminal EP or using IS DBX31, ...DBX21.7 ("Pulse enable") does not cancel the
function. As a result, the drive will press against the fixed stop again without any further operating action when
the machine is restarted.
306
; If X reaches a position greater
; 17mm FXS is activated
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions