4.4.2
External device monitoring (EDM)
Overview
The external switching elements (external device monitoring, EDM) must be inspected
in line with the regulations which apply at the place of installation or the required relia‐
bility of the safety function.
External device monitoring (EDM) monitors the status of downstream contactors.
Important information
NOTE
Because the multiple light beam safety device does not have integrated external device
monitoring, this must be implemented in the external control, if required.
Prerequisites
•
Positively guided contactors are used for shutting down the machine.
If the auxiliary contacts of the positively guided contactors are connected to the
external device monitoring, the external device monitoring checks whether the
contactors drop off when the OSSDs are switched off.
4.4.3
Connection diagrams
Connection diagram for RLY3-OSSD2 with restart interlock and external device moni‐
toring
1
2
4
3
5
2) PELV
r
S
ys
te
m conne
c
ti
on
+24 V DC
OSSD1
OSSD2
0 V
n.c.
1
2
4
3
5
s
S
ys
te
m conne
c
ti
on
+24 V DC
In2
In1
0 V
n.c.
F2 F1
+24 V DC
0 V DC
K1
K2
E243749/01/2020-04-02
R1
Y1
Y2
24
A2
14
S1
I1
I2
23
A1
13
RLY3-OSSD2
k2
z
k1
k2
k1
z
x
y
x
1)
y
F0
L+
L–
deTec2 Core
deTec4 Core
k2
k1
S1
Figure 15: Connection diagram for RLY3-OSSD2 with restart interlock and external device moni‐
toring
1)
Output circuits: These contacts must be incorporated into the control such that the dan‐
gerous state is brought to an end if the output circuit is open. For categories 4 and 3, they
must be incorporated on dual-channels (x, y paths). Type 2 devices are suitable for use up
to PL c. Single-channel incorporation into the control (z path) is only possible with a single-
channel control and taking the risk analysis into account.
2)
SELV/PELV safety extra-low voltage.
PROJECT PLANNING
4
8021554/14Q7/2020-04-27 | SICK
O P E R A T I N G I N S T R U C T I O N S | deTem2 Core IP69K
23
Subject to change without notice