User Documentation

7 Example applications | Dual-channel safety door monitoring with automatic reset and controlled shutdown and emergency stop
87u-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 1 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
Optional: brake
Notes Autostart is also possible if the NC
circuits from K3 and K4 are connected 
to 3.3 and 3.4.
As soon as the enabling on the
frequency converter is withdrawn, the 
converter must execute a controlled
shutdown.
Exclusion of fault: No external energy 
might be fed into the control line of
the brake (e.g. caused by cable fault)
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-2DI-SIL-DLY UR20-4DO-P
K4
K3
K4K3
S1
S3
S2
L+(+24V)
M (0V)
Reset
K4
K3
Emergency stop
Safety door
(closed)
Enable
Converter
Example application for dual-channel safety door monitoring with automatic reset and controlled
shutdown and emergency stop
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 the safety door contact as well as a cross-cir-
cuit in their supply lines does not result in the failure of the
emergency stop mechanism and is detected within the
fault-reaction time.
After opening the safety door and the expiration of the delay
time set in the UR20-PF-O-2DI-SIL-DELAY, the spring-oper-
ated interlock can be activated with the unlock button and
the safety door can be opened. When the power supply is
turned off, the safety door cannot be opened if the locking
mechanism is engaged. We recommend using switches with
mechanical unlocking capabilities.
The PF-O-xDI-SIL module switches the 24V power
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 PF-O-xDI-SIL has switched
on the 24V supply. To reset the system, press the reset but-
ton for 0.1 to 2s after switching on the power supply, even
when automatic reset is used.
7.13 Dual-channel safety door monitoring with automatic reset and controlled shutdown and emer-
gency stop