Safe Software Limit Switches (Se) - Siemens SINUMERIK 840D sl Function Manual

Safety functions integrated in the system/drive

7.7 Safe software limit switches (SE)

7.7 Safe software limit switches (SE)
Note
The function "safe software limit switches" (SE) is also known as "safe limit positions".
Description
The "safe software limit switches" function (SE) can be used to implement protective functions
for operating personnel and machinery or working zone/protection zone delimination on an
axis-for-axis basis. For example, this function can replace hardware limit switches.
Two "safe software limit switches" (SE1 and SE2) are available for each axis. If the SE function
is active, software limit switch position pair SE1 or SE2 can be selected as a function of SGE
"SE selection".
Defining the upper and lower limit values
The position limit values for the software limit switch position pairs 1 and 2 are defined in the
following machine data:
for 840D sl:
MD36934 $MA_SAFE_POS_LIMIT_PLUS[n]
MD36935 $MA_SAFE_POS_LIMIT_MINUS[n]
for SINAMICS S120:
p9534[n] SI Motion SLP (SE) upper limit values (Control Unit)
p9535[n] SI Motion SLP (SE) lower limit values (Control Unit)
Note
The upper and lower position limit values must be selected so that when the axis is traversing
in this direction, the software limit switches - that are used as standard - are first reached.
Functional features
The most important functional features include:
● Software limit switches are safely defined and evaluated as a software function
● Configurable stop response when software limit switches are passed
● The stop response is implemented internally in the software (and is therefore faster than a
hardware limit switch response) when software limit switches are passed (i.e. actuated)
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Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated