User Documentation

7 Example applications | Dual-channel safety door monitoring with automatic reset and emergency stop
79u-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
– Automatic reset
– Monitoring of external contactors
(EDM)
Safety sensor / operating
mechanism
– Emergency stop button
– Position switch
Notes The application must be compatible with
the automatic start-up function.
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
UR20-PF-O-xDI-SIL UR20-4DO-P
K4
K3
K4K3
S1
S3
S2
L+(+24V)
M (0V)
Reset
M
K4
K3
Emergency stopSafety door (closed)
Example application for dual-channel safety door monitoring with automatic reset and emergency
stop
1)
Switchable modules see section4.3
When the emergency stop button is pushed or the safety
door is opened, the UR20-PF-O-2DI-DELAY-SIL switches off
the 24V supply for the modules
1)
within the safety segment
and thus also contactors K3 and K4. The failure of a switch-
ing element in the emergency stop button or the safety door
contacts as well as a cross-circuit in their supply lines does
not result in the failure of the emergency stop mechanism
and is detected within the fault-reaction time.
The UR20-PF-O-2DI-DELAY-SIL switches on the 24V supply
for the following modules
1)
within the safety segment if:
– the emergency stop button is unlocked
– and the safety door is closed
– and the feedback circuit (NC contacts of K3 and K4) is
closed.
Contactors K3 and K4 are controlled by the PLC and can
switch on as soon as the UR20-PF-O-2DI-DELAY-SIL module
has switched on the 24V supply. To reset the system, press
the reset button for 0.1 to 2s after switching on the power
supply, even when automatic reset is used.
7.5 Dual-channel safety door monitoring with automatic reset and emergency stop