Siemens 6SN1123-1AA00-0DA2 Configuration Manual page 350

02.12
05.01
9.3Safety of machinery – safety–related parts of controls according to EN ISO 13849–1:2008
Function
The power unit controls the power feed to the individual motor windings.
The gating logic on the control module clocks the 6 power transistors using a
specific pattern to generate a rotating field. An optocoupler is connected bet-
ween the gating logic and each control amplifier of a power transistor to provide
electrical isolation. Power supply P5 of the optocoupler is fed via the NO contact
of safety relay K1. When the Safe Torque Off function is activated, the NO con-
tact of the safety relay is opened and the NC contact (= feedback contact) is
closed. The NO and NC contacts in the safety relay are positively driven. The
state of the safety relay (NO contact) must be evaluated via the feedback signal
contact AS1/AS2.
Control
When the Safe Torque Off function is active (in the normal state without fault)
the contacts of the NO contact –K1 are open and the power supply to the opto-
couplers is interrupted.
In order that the control module of the SIMODRIVE 611 identifies the state Safe
Torque Off, and processes it in the sequence control, the logical signal level of
terminal 663 is signaled to the control module via an optocoupler. If the Safe
Torque Off function is active, this input immediately generates a pulse inhibit via
the control logic.
The feedback signal contact of the safety relay must be evaluated in every case
and must be used to directly control a second shut off signal path.
Fig. 9-10
Table 9-2 Value integrated safety relay
Terminal Designation
AS1 Contact 1
AS2 Contact 2
663 Control input "start inhibit"
9 Enable voltage FR+ (internal)
19 Reference FR– (external)
B value of the integrated safety relay: 20,000,000 operating cycles,
10d
service life: 20 years
© Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
FR+
P5LT
FR–
Supply
Optocoupler/LWL
SIMODRIVE closed–loop control STO control block diagram
Description
Relay feedback signal contact
Start inhibit
Nominal resistance of the ex-
citation coil at 20 _C
w 500 Ω
9 Cabinet Design and EMC
AS1
AS2
9
663
19
Type Area
Ö 30 V DC/ max. 2 A
250 V AC/ max. 1 A
E 21 ... 30 V DC, maximum
switching frequency: 6/min ope-
rating cycles: min. 20000 me-
chanical lifetime: 10 million ope-
rating cycles
V +24 V
V Ground
9
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