Safety Function And Safe State - Pepperl+Fuchs SJ2-SN Manual

Functional Safety SJ2-SN, SJ3,5-S(1)N
Planning
3.3

Safety Function and Safe State

Safe State
The safe state of the device is the high impedance state (low current).
Applications with control units or safety functions where the safe state is the low impedance
state (high current) were not evaluated.
Safety Function
Figure 3.1
a Length of the reference object
b Width of the reference object
c Thickness of the reference object
d Distance to the slot base
s Current operating distance (immersion depth)
S Assured operating distance (immersion depth) of a PDDB
ao
S Assured release distance (immersion depth) of a PDDB
ar
s Rated immersion depth (lateral)
n
The SN sensor signals the safe state when the reference object is inside of the slot (s > S
The assured operating distance S
The S1N sensor signals the safe state when the reference object is outside of the slot (s < S
The assured release distance S
These distances are valid when using the following reference objects:
Sensor
Dimensions of the reference
object (a x b x c)
Distance to the slot base (d)
Material of the reference
object
Table 3.1
To ensure the safety of the safety loop according to SIL 2, only use control units according
to EN 60947-5-6 (NAMUR).
12
Lateral immersion of the reference object
a
S s s
0
ar
Slot length
Distance values for the design of the safety function (abstract figure)
for the SN sensor is 8.0 mm.
ao
for the S1N sensor is 0.0 mm.
ar
SJ2-SN
5 mm x 8 mm x 0.5 mm
 0.5 mm
Aluminum 3.0255.10
Distance to the slot base
S
n ao
b
d
ao
SJ3,5-S(1)N
10 mm x 7 mm x 0.3 mm
2.5 mm
Aluminum 3.0255.10
).
).
ar