Siemens SINAMICS S120 Function Manual page 499

Fixed stop is reached
As soon as the axis comes into contact with the mechanical fixed stop, the closed-loop
control in the drive raises the torque so that the axis can move on. The torque increases up
to the value specified in the task and then remains constant. The status bit r2683.12 "Fixed
stop reached" is set depending on the binector input p2637 (Fixed stop reached):
● If the following error exceeds the value set in parameter p2634 (fixed stop: maximum
● If the status is set externally via the signal at binector input p2637 (fixed stop reached)
In travel to fixed stop, the clamping torque or clamping force in the traversing block is
configured via the task parameter. It is specified in the units 0.01 Nm or 1 N (rotary / linear
motor). The function module is coupled to the torque limit of the basic system via the
connector output r2686[0] (torque limit upper) or r2686[1] (torque limit lower), which are
connected to the connector input p1528 (torque limit upper scaling) or p1529 (torque limit
lower scaling). The connector outputs r2686[0] (torque limit upper) and r2686[1] (torque limit
lower) are set to 100% when fixed stop is not active. During active fixed stop, r2686[0]
(torque limit upper) or r2686[1] (torque limit lower) are evaluated as a percentage of
p1522/p1523 in such a way that the specified clamping torque or clamping force is limited.
When the fixed stop is acknowledged (p2637), the "Speed setpoint total" (p2562) is frozen,
as long as the binector input p2553 (fixed stop reached message) is set. The speed control
holds the setpoint torque due to the applied speed setpoint. The setpoint torque is output for
diagnosis via the connector output r2687 (torque setpoint).
If the parameterized clamping torque is reached at the fixed stop, the status bit r2683.13
"Fixed stop clamping torque reached" is set.
Once the "Fixed stop reached" status has been detected, the traversing task "Travel to fixed
stop" is ended. The program advances to the next block depending on the task
parameterization. The drive remains in fixed stop until the next positioning task is processed
or the system is switched to jog mode. The clamping torque is therefore also applied during
subsequent waiting tasks. The continuation condition CONTINUE_EXTERNAL_WAIT can be
used to specify that the drive must remain at the fixed stop until a step enabling signal is
applied externally.
As long as the drive remains in fixed stop, the position setpoint is adjusted to the actual
position value (position setpoint = actual position value). Fixed stop monitoring and controller
enable are active.
Note
If the drive is in fixed stop, it can be referenced using the control signal "Set reference point".
If the axis leaves the position that it had at detection of the fixed stop by more than the
selected monitoring window for the fixed stop p2635, then the status bit r2683.12 is reset. At
the same time, the speed setpoint is set to 0, and fault F07484 "Fixed stop outside of the
monitoring window" is triggered with the reaction OFF3 (quick stop). The monitoring window
can be set using the parameter p2635 ("Fixed stop monitoring window"). It applies to both
positive and negative traversing directions and must be selected such that it will only be
triggered if the axis breaks away from the fixed stop.
Drive functions
Function Manual, (FH1), 04/2014, 6SL3097-4AB00-0BP4
following error) (p2637 = r2526.4) or
(for p2637 ≠ r2526.4)
Function modules
8.8 Basic positioner
499