Siemens Sinamics S120 Function Manual page 81

M onitoring with an encoder
The Safety Integrated Functions with encoder are configured with p9506 = 0 (factory setting)
or p9506 = 2 in the expert list or by selecting "with encoder" in the Safety screen.
● If p9506 = 0:
Braking is monitored with the "Safe Acceleration Monitor" function.
● If p9506 = 2:
Here, also for SS1, the monitoring function "Safe Brake Ramp" is active.
More detailed information on actual value acquisition with encoder can be found in Section
"Notes regarding safe actual value sensing using an encoder system (Page 147)".
M onitoring without an encoder
The Safety Integrated functions without encoder are configured in the expert list using p9506
= 1 or p9506 = 3 or by selecting "without encoder" in the Safety screen form.
● For p9506 = 1, t he following applies:
Here, also for SS1, the monitoring function "Safe Brake Ramp" is active.
● For p9506 = 3, t he following applies:
Braking is monitored with the "Safe Acceleration Monitor" function. The behavior
corresponds to "monitoring with encoder".
Tak ing into account the slip of an induction motor
For Safety Integrated without encoder (depending on the drive load), as a result of slip
(deviations between electrical and mechanical speed), deviations can occur between the
safely determined electrical speed and the mechanical speed at the motor shaft.
Not e
Sudden changes in the current and voltage curve (e.g. sudden change in the setpoint setting
and load) and very small absolute values with a high proportion of noise generally result in
faults of the safe encoderless actual value acquisition and must be avoided.
More detailed information on actual value acquisition without encoder can be found in
Section "Notes regarding setting parameters for safe actual value sensing without encoder
(Page 154)".
Not e
S c ope of functions
There are fewer Safety Integrated Extended Functions available "without encoder" than "with
encoder" (see Section "Drive monitoring with or without encoder (Page 32)").
Not e
S af ety Integrated functions "without encoder" f or group drives
The Safety Integrated functions "without encoder" are also permitted for group drives
(several motors connected to one power unit).
Safety Integrated
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
81