Siemens SINUMERIK 840D Function Manual page 553

Availability
The "CP SW limit monitoring" function can only be activated for following axes from:
● Generic couplings, type "Freely programmable (CPSETTYPE[FAx] = "CP")
● Couplings (generic coupling with CPSETTYPE[FAx] not equal to "CP", coupled motion,
electronic gearbox, master value coupling or synchronous spindle) with a maximum of one
active leading axis/spindle
In all other cases (and when "CP SW limit monitoring" is not activated) the previous function of
the software limit switch monitoring is active (see Chapter "Limit switch monitoring" in the
Function Manual, Basic Functions, A3: Axis Monitoring, Protection Areas).
Monitoring and setting the brake
The "CP-SW limit monitoring" function checks, in every IPO cycle, as to whether the movement
of the following axis/spindle can be enabled for the following IPO cycle, so that the axis can
always stop in plenty of time before the software limit switch. If this is not the case, for the
following axis, a "CP-SW limit stop" is set; this signifies unconditional direction-specific braking
along the contour.
Transferring the brake to the axes
Setting the brake means that the coupling-independent motion component (CMD and CORR
component) of the following axis is stopped. On the other hand, the coupling-dependent motion
component (DEP component) of the following axis can only be braked by braking the leading
axes.
For couplings (generic coupling with CPSETTYPE[FAx] not equal to "CP", coupled motion,
electronic gearbox, master value coupling or synchronous spindle) with a maximum of one
active leading axis/spindle, the brake is also set for the (only) active leading axis in the collision
direction (depending on the coupling factor).
For generic couplings, type "freely programmable (CPSETTYPE[FAx] = "CP"), the brake is only
transferred to all of the active leading axes, if the coupling property CPMBRAKE[FAx] Bit 0 = 1
has been programmed (see "Reaction to stop signals and commands (CPMBRAKE)
(Page 535)").
The collision direction depends on the coupling factor for the specific leading axis: With a
negative coupling factor, the collision direction reverses, there is no transfer for a coupling
factor of "zero". For non-linear couplings (e.g. curve table), the coupling factor is derived from
the gradient, determined as linear approximation.
Note
A brake set for a following axis can only influence its leading axes as long as the coupling is
active.
Braking behavior
The normal acceleration ramp is used when braking the axes towards the software limit switch
along the contour, maintaining the coupling definition.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
M3: Coupled axes
14.5 Generic coupling
553