Dual-Channel Emergency Stop Monitoring - Weidmuller UR20-4DI-4DO-PN-FSOE Manual

7 Example applications | Dual-channel emergency stop monitoring
7.2

Dual-channel emergency stop monitoring

Achievable safety rating
Stop category
Features
Safety sensor / operating
mechanism
Notes
All examples shown are proposals without
warranty. In any case the operator has to per-
form a safety review of the entire site.
L+(+24 V)
M(0 V)
Example application for dual-channel emergency stop monitoring
Switchable modules see section 4.3
1)
76
Category 4 EN ISO 13849-1
PLe EN ISO 13849-1
SIL 3 EN 62061/61508
0 EN 60204-1
– Dual-channel monitoring
– Cross-connection detection
– Manual reset
– Monitoring of external contactors
(EDM)
Emergency stop button
Autostart is possible if the NC circuits
from K3 and K4 are attached to 3.3 and
3.4.
UR20-PF-O-xDI-SIL
Restart K3 K4
u-remote IP20 modules for functional safety manual
When the emergency stop button is pushed, the
PF-O-xDI-SIL switches off the 24 V supply for the mod-
ules within the safety segment and thus also contactors K3
1)
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 within the safety segment if:
1)
– 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.
UR20-4DO-P
1.1 1.1
1.2 1.2
1.3 1.3
1.4 1.4
2.1
2.2
2.3
2.4
3.1 3.1
3.2 3.2
3.3 3.3
3.4 3.4
4.1 4.1
4.2 4.2
4.3 4.3
4.4 4.4
K3 K3
K4 K4
M
1484600000/04/06.2017