Sensor Connection Using The 4--Terminal Concept - Siemens Sinumerik 840D sl Function Manual

Connecting Sensors/Actuators
7.1 Safety- -relevant input/output signals
IM 151--1
High Feature
PROFIBUS
with PROFIsafe
Figure 7-5 Sensor connection using fail--safe inputs according to the 3--terminal concept
7.1.4 Sensor connection using the 4- -terminal concept
For the 4--terminal concept, four terminals are required at the fail--safe input
module to connect a sensor that utilizes a contact (e.g. Emergency Stop push-
button). Faults/errors in the sensors and actuators can be detected in conjunction
with the SPL--CDC and forced checking procedure or the forced checking as a
result of the process itself. The connecting cables are generally monitored autono-
mously by the fail--safe input module.
The following applies to the safety--related sensor connection:
2 safety inputs + 2 standard test outputs
Example
2 inputs (to read--in the 2--channel sensor signals via SGE) and 2 standard test
outputs (for the forced checking procedure) are required for the fail--safe connec-
tion of a sensor. The test outputs are supplied from the two power supply voltages
(VS1, VS2) of the safety input module. For the connection concept with 4 termi-
nals, both equivalence (NC contact/NC contact, NO contact/NO contact) as well as
non--equivalence (NC contact/NO contact) contact versions are possible.
7-200
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
F--DI
ET 200S PROFIsafe
VS
To activate and
e.g. user
deactivate
agreement
Non--equivalence
contacts (NC contact/
NO contact) with the
3--terminal concept
Remark: In this case, it is not possible
to connect the pushbuttons in series!
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10/15