Siemens Sinamics S120 Function Manual page 377

Safety Integrated Extended function uses the rotating motor encoder. The gearbox is
parameterized using p9521/p9522. The spindle pitch is parameterized in p9520. To calculate
the load-side absolute position, EPOS directly uses the load-side linear scale. In this
example, EPOS does not have to take into account the gearbox ratio and spindle pitch.
Example 3:
Safety Integrated Extended functions monitor the linear axis using the rotating motor
encoder. EPOS referenced using the same rotary motor encoder.
● p2506 = 10000, p9520 = 5 mm/revolution => a position of 10000LU (r2521) corresponds
● p2506 = 5000, p9520 = 5 mm/revolution => a position of 10000LU (r2521) corresponds to
Using the spindle pitch parameterized in parameter p9520, rotary motion is converted into
linear motion. EPOS does not take into account spindle pitch. Instead, the LUs are defined in
the number of load revolutions in p2506. The load revolutions refer to the movement of the
ball screw, that is, the motion after the gearbox. The ratio for the gearbox used must be
parameterized in p9521/p9522 for Safety Integrated Extended functions and in p2504/p2505
for EPOS. For a gearbox to convert from 4 motor revolutions to 3 load revolutions, set:
● p9521 = 3
● p9522 = 4
● p2504 = 4
● p2505 = 3
Drive functions
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Gear unit
Motor
Encoder
Figure 7-21 Example 2: EPOS and safe referencing_linear
to 5 mm (r9708)
10 mm (r9708)
Gear unit
Motor
Encoder
Figure 7-22 Example 3: EPOS and safe referencing_linear
Function modules
7.8 Basic positioner
375