Principle Of Ss1 In A Safety Function - Siemens 6SN1123-1AA00-0DA2 Configuration Manual

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05.01
9.3Safety of machinery – safety–related parts of controls according to EN ISO 13849–1:2008
9.3.7

Principle of SS1 in a safety function

SRP/CS
a
SENSE
Fig. 9-13 Principle of SS1, two–channel structure
The SS1 safety function can also be achieved by using the STO safety function
as basis and then adding a supplementary circuit. Also in this case, a basic
two–channel architecture is configured.
SENSE
The SENSOR subsystem can have the same structure as described in
Chapter 9.3.6.
Activating the safety function using the SENSE subsystem immediately initiates
that the drive is stopped through a single channel. At the same time, a safe tim-
er is started in EVALUATE.
The drives can be stopped, for example, by ramping–down the drives in a con-
trolled fashion via the NC program, by inhibiting the drive enable terminal 64 or
the axes–specific control enable, terminal 65.
The OFF delay of the timer should be set so that the drive has come to a stand-
still along the fast stopping ramp before this delay time has expired. After the
timer has expired, the drive is safely switched into a no–torque condition accor-
ding to Chapter 9.3.6.
EVALUATE
The EVALUATE subsystem must be expanded by a safety–related OFF–delay.
© Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
t
v
SRP/CS
b
EVALUATE
9 Cabinet Design and EMC
–K2
Line contactor
Line infeed
–K1
M
Safety relay
RF
Control module
Power module
M
3
SRP/CS
c
RESPOND
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