BECKHOFF TwinSAFE - Manual (Page 116)

Circuit examples
114 Application Guide TwinSAFE
2.19 Networked plant (Category 4, PL e)
In this case, 2 plants are connected via Ethernet. The path can also be implemented by a Wireless
Ethernet connection. Each station switches the outputs K1 / K2 on only if the second machine does not
signal an emergency stop. The signals from the emergency stop button, the restart and the feedback loop
are wired to safe inputs. The output of the ESTOP block is linked to an AND block and additionally
signalled to the other machine via the network. The ESTOP output of the other machine is linked to an
AND block and the AND output then switches the contactors on the safe output terminal.
Testing and checking for discrepancy are activated for the input signals. The testing of the outputs is also
active.
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