Siemens SIMATIC ET 200eco PN, Operating Instructions Manual

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ET 200eco PN
Operating Instructions, 06/2022, A5E01250250-AN
262
Fail-safe shutdown of ET 200eco PN standard
modules
G
G.1 Back-up oriented shutdown of ET 200eco PN standard modules
Introduction
The following structure describes how to perform a fail-safe shutdown of ET 200eco PN
standard modules.
In the configuration shown in the diagram below (e.g. with the safety shutdown device
3SK1), all digital outputs that are connected to the 2L+ and 2M supply (24 V switched) of the
ET 200eco PN standard modules are switched to the safe OFF state. This step achieves the
safety class SIL2/category 3/PL d.
Principle of operation
The higher-level safety shutdown device (e.g. 3SK1) disconnects the supply 2L+ and 2M
switched. The digital outputs of the ET 200eco PN standard modules operated at the 2L+ and
2M (24 V switched) supply are switched to the safe state. The digital outputs connected to
the supply 1L+ and 1M (24 V non-switched) are not intended for switching under normal
operating conditions and cannot be safely shutdown.
There is no opposite influence of the outputs.
WARNING
Pay attention to the potential groups
When a digital output is connected to a digital input, pay attention to the respective poten­
tial groups. Depending on the configuration, 1M and 2M can then be connected, resulting in
elimination of the electrical isolation between 1L+ and 2L+. In this case, a safety-oriented
shutdown is not possible.