X20(c)SC2212
Data sheet V1.141 X20(c)SC2212 Translation of the original documentation
15
7.4 Connecting multi-channel sensors with contacts
Input 2
Pulse 2
Pulse 1
Input 1
Input n
Pulse m
Input 2
Pulse 2
Pulse 1
Input 1
Input n
Pulse m
Input 2
Pulse 2
Pulse 1
Input 1
Input n
Pulse m
Figure 8: Connecting multi-channel sensors with contacts
Multi-channel switches (mode selector switches, switching devices with "shift key" capability) can be connected
to multiple safe digital input modules.
If signals are evaluated internally in the module (see image to the left), the same pulse must be configured for all
of the inputs being used. If signals are evaluated across all modules (see image to the right), all of the inputs must
be configured to use an external pulse. In this type of application, pulse evaluation with the "default" pulse is not
suitable; therefore, a separate pulse signal with approx. 4 ms low-phase is available.
In this case, multi-channel evaluation must be handled in the safety application (PLCopen function block
"SF_ModeSelector"). The category achieved per EN ISO 13849-1:2015 in this way depends on the error models
of the switching element (e.g. mode selector switch) and must be examined in combination with the error detection
present in the PLCopen function block.
7.5 Connecting electronic sensors
OSSD2
OSSD1
24 VDC
OSSD
24 VDC
Input 2
Pulse 2
Pulse 1
Input 1
Input 2
Pulse 2
Pulse 1
Input 1
Figure 9: Connecting electronic sensors
Electronic sensors (light curtains, laser scanners, inductive sensors, etc.) can be connected directly to safe digi-
tal input modules. The switching thresholds of the input channels must be taken into account for these types of
applications.
With single-channel wiring (see image on the left), the module satisfies Category 3 requirements in accordance
with EN ISO 13849-1:2015. With two-channel wiring (see image on the right), the module satisfies Category 4
requirements in accordance with EN ISO 13849-1:2015. Be aware that this statement applies only to the module
and not the wiring or connected electronic sensor. You are responsible for wiring the sensor in accordance with
the required category and within the specifications set forth by the manufacturer of the electronic sensor.