Emergency Stop Connection, Dual-Channel, Equivalent Pre-Evaluation; Figure 28: Connection 2 × Emergency-Off Switch, Dual Channel, Equivalent - WAGO 750 Manual

80 Commissioning
7.5.1.2 Emergency Stop Connection, Dual-Channel, Equivalent Pre-
Evaluation
Figure 28: Connection 2 × Emergency-Off Switch, Dual Channel, Equivalent Pre-Evaluation
For applications that require single fault security, e.g., emergency off and
emergency stop, you can connect two digital inputs via two switching elements of
safe sensors to the F I/O module.
Use the WAGO parameterization tool to set the parameters.
Set the Pre-Evaluation parameter for the digital inputs used to "Equivalent." In
addition, set the Discrepancy Time parameter to the discrepancy time required
for the two switching elements.
You can set the Short Circuit Test parameter of both inputs used to "Activated"
or "Deactivated." Note that the Short Circuit Test parameter must have the
same setting for both digital inputs.
With this wiring, you can achieve a risk reduction of SIL3/Cat.4/PL e.
If you connect the digital inputs via the switching elements directly to the field
voltage of +24 V or to two semiconductor outputs of a sensor, then you have to
set the Short circuit test parameter to "Deactivated" because otherwise the
F I/O module detects a short circuit and outputs the "Short circuit" diagnostic
message.
Manual
Version 1.0.0, valid from HW/SW Version 01/01
WAGO I/O System 750
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