User Documentation

7 Example applications | Dual-channel emergency stop monitoring
76 1484600000/07/11.2020u-remote IP20 modules for functional safety manual
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
– Manual reset
– Monitoring of external contactors
(EDM)
Safety sensor / operating
mechanism
Emergency stop button
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
3.1
3.2
3.3
3.4
4.1
4.2
4.3
4.4
M
UR20-PF-O-xDI-SIL UR20-4DO-P
K4
K4
K3
K3Restart
K4
K3
L+(+24 V)
M(0 V)
Example application for dual-channel emergency stop monitoring
1)
Switchable modules see section4.3
When the emergency stop button is pushed, the
PF-O-xDI-SIL switches off the 24V supply for the mod-
ules
1)
within the safety segment and thus also contactors K3
and K4. The failure of a switching element in the emergency
stop button or a cross-circuit in its supply lines does not re-
sult in the failure of the emergency stop mechanism and is
detected within the fault-reaction time.
The PF-O-xDI-SIL switches on the 24V supply for the
modules
1)
within the safety segment if:
– the emergency stop button is unlocked
– 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 PF-O-xDI-SIL has switched on
the 24V supply.
7.2 Dual-channel emergency stop monitoring