Safety engineering
Device modules
Safe inputs
1
36
EDS94AYAE EN 6.0
1.2.4.3 Connection of active sensors
The safe sensor inputs I1A ... I4B are suitable for active sensors.
PN−switched input signals are permissible.
The line monitoring must comply with the requirements of the category 3. Drive−based
safety does not provide for line monitoring.
These errors are detected:
ƒ Non−equivalent input signals after the discrepancy time.
1.2.4.4 Example circuits
GxI
IxB
IxA
SM...S
SSP94SM352
Fig. 1−9 Example circuit − active sensor
GxI
IxB
IxA
SM...S
M
P
SSP94SM352
Fig. 1−10 Functional example of PN−switching sensor
S Sensor
P Positive path
M Negative path