User Documentation

7 Example applications | Dual-channel light curtain monitoring (AOPD type 4) and emergency stop monitoring
77u-remote IP20 modules for functional safety manual 1484600000/07/11.2020
Achievable safety rating Category 4 ENISO13849-1
PLe ENISO13849-1
SIL 3 EN62061/61508
Stop category 0 EN60204-1
Features – Dual-channel monitoring
– Cross-connection detection
– Start button
– Monitoring of external contactors
(EDM)
– Self-test of the OSSD in the AOPD
Safety sensor/operating
mechanism
– Emergency stop button
– AOPD type 4 (2 semiconductor
outputs, P-switching)
Notes Autostart is possible if the NC circuits
from K3 and K4 are attached to 3.3 and
3.4.
All examples shown are proposals without
warranty. In any case the operator has to per-
form a safety review of the entire site.
1.1
1.2
1.3
1.4
3.1
3.2
3.3
3.4
4.1
4.2
4.3
4.4
1.1
1.2
1.3
1.4
2.1
2.2
2.3
2.4
2.1
2.2
2.3
2.4
3.1
3.2
3.3
3.4
4.1
4.2
4.3
4.4
M
UR20-PF-O-DELAY-SIL
LC1
S1
UR20-4DO-P
L+(+24 V)
K4
K4
K3
K3
Restart
K4
K3
M(0 V)
+ OSSD1OSSD2
–
AOPD type 4 (receiver)
Emergency stop
Example application for dual-channel light curtain monitoring (AOPD type 4) and emergency stop
monitoring
1)
Switchable modules see section4.3
When the emergency stop button is pushed or the ac-
tive optoelectronic protective device (AOPD) reacts, the
UR20-PF-O-2DI-DELAY-SIL switches off the 24V supply for
the modules
1)
within the safety segment and thus also for
contactors K3 and K4. The failure of a switching element
in the emergency stop button or the AOPD as well as a
cross-circuit in their supply lines does not result in the failure
of the corresponding safety device and is detected within
the fault-reaction time. For this purpose, the AOPD must
generate a test pulse on its safety outputs at least once per
second.
When using a UR20-PF-O-2DI-DELAY-SIL: If the DIP switch
which is assigned to the corresponding safety circuit is
switched on (in the example DIP switch 2 for LC1) so that
an AOPD generating own test pulses can be connected, it
might be necessary to have a shielded cable installation and
cross-circuit fault detection via the AOPD, depending on the
required safety level.
The UR20-PF-O-2DI-DELAY-SIL switches on the 24V supply
for the modules
1)
within the safety segment if:
– the emergency stop button is unlocked
– and the active optoelectronic protective device (AOPD) is
free
– and the feedback circuit (NC contacts of K3 and K4) is
closed
– and the start push button has been pushed and released
again.
Contactors K3 and K4 are controlled by the PLC and can
switch on as soon as the UR20-PF-O-2DI-DELAY-SIL has
switched on the 24V supply.
7.3 Dual-channel light curtain monitoring (AOPD type 4) and emergency stop monitoring