Siemens SINUMERIK 840D sl Function Manual page 174

Connecting Sensors/Actuators
7.1 Safety-relevant input/output signals
Note
Cross-circuit fault detection in the input module is not required. Measures against
cross-circuit faults are required only for equivalence contacts (NC contact/NC
contact, NO contact/NO contact) if the cable has been routed so that it is very
exposed, e.g. for cables connecting handheld terminals. This can be mechanically
implemented in the cable, e.g. using the appropriate shielding.
IM 151-1
High Feature
PROFIBUS
with
PROFIsafe
Fig. 7-7 Sensor connection using the 4-terminal concept
7-174
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
F-DI
VS 1
VS 2
Two circuit
Closed-circuit
principle (de-activation)
VS 1
VS 2
Double open
conductor loops
(activating)
ET 200S PROFIsafe
Test outputs
e.g.
Emergency
Stop
e.g. user
agreement
© Siemens AG, 2006. All rights reserved
03.06
Equivalence
contacts (NC
contact/NC
contact) with the
4-terminal
concept
Equivalence
contacts (NO
contact/NO
contact) with the
4-terminal
concept