
Safety engineering
Device modules
Safe inputs
33
EDS94AYAF EN 1.0
1.2.5.3
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 or category 4.
Drive−based safety does not provide for line monitoring.
These errors are detected:
ƒ
Non−equivalent input signals after the discrepancy time.
1.2.5.4
Example circuits
G x
I
IxB
IxA
SM...
S
SSP94SM352
Fig. 1−9
Example circuit − active sensor
G x
I
IxB
IxA
SM...
S
M
P
SSP94SM352
Fig. 1−10
Functional example of PN−switching sensor
S
Sensor
P
Positive path
M
Negative path