Figure 27: Connection 2 X Emergency-Off Switch, Dual Channel, Equivalent - WAGO -I/O-SYSTEM 750 Manual

68 Connect Devices
Alternative measures for fault detection!
You can take alternative measures (e.g., antivalent evaluation) for fault detection
to achieve the required risk reduction for your application (e.g., SIL3/Cat.4/PL e).
The safety parameters of the F I/O module do not change.
Figure 27: Connection 2 x Emergency-Off Switch, Dual Channel, Equivalent Evaluation
For emergency off applications that require single fault security, you can connect
two digital inputs via two switching elements (two-channel emergency off
switches with two break contacts) to the F I/O module.
Use the WAGO parameterization tool to set the parameters. For more information
about configuring the F I/O module, read section "Parameterization of the
F I/O module with the WAGO Parameterization Tool".
Set the Dual channel evaluation parameter to "yes" for the digital inputs used
and the Valence evaluation parameter 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 "active" or
"not active". Please note that the Short circuit test parameter must be set the
same for both digital inputs.
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 "not active" because otherwise the
F I/O module detects a short circuit and outputs the "Short circuit" diagnostic
message.
Manual
Version 1.4.2, valid from HW/SW Version 01/02
750-667/000-003 4FDI/4FDO 24V/2A PROFIsafe V2 iPar
WAGO-I/O-SYSTEM 750