Siemens SIMATIC S7-1200 - 10.3.6.2 Hardware and software limit switches for motion control

Technology instructions
10.3 Motion control
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
713
10.3.6.2
Hardware and software limit switches for motion control
Use the hardware and software limit switches to limit the "allowed travel range" and the
"working range" of your axis.
①
Mechanical stop
A
Allowed travel range for the axis
②
Lower and upper hardware limits
B
Working range of the axis
③
Lower and upper software limits
C
Distance
Hardware and software limit switches must be activated prior to use in the configuration or in
the user program. Software limit switches are only active after homing the axis.
Hardware limit switches
Hardware limit switches determine the maximum travel range of the axis. Hardware limit
switches are physical switching elements that must be connected to interrupt-capable inputs
of the CPU. Use only hardware limit switches that remain permanently switched after being
approached. This switching status can only be revoked after a return to the allowed travel
range.
Table 10- 50 Available inputs for hardware limits
Description
CPU
RPS, LIM-, and LIM+
1
Built-in I/O
CPU 1211C
I0.0 - I0.5
CPU 1212C
I0.0 - I0.7
CPU 1214C, CPU 1215C, and
CPU 1217C
I0.0 - I01.3
SB I/O
All S7-1200 CPUs
I4.0 - I4.3
1
Reference Point Switch input (RPS), Negative Travel Limit input (LIM-), and Positive Travel Limit
input (LIM+)