Safety Integrated - Industry - Siemens

Ex. No.
2
Timing diagram
The timing diagram below (explanation is provided after the
diagram) illustrates the following case: While the hazardous
machine is active, the door is opened (by force); during this
process, the actuator breaks off the door and gets stuck in the
safety position switch.
RELEASE
START
SEP_ACT
HINGED_SW
ACTUATOR
ACT_PAS
COIL
t1
t2 t3 t4 t5
192 Functional Example No. AS-FE-I-002-V10-EN
t
t
t
t
t
t
t
G_FB_XX_093
Time t1 t2 t3 t4 t5
Bit
RELEASE Enable
given
START Start
request
SEP_ACT Door
closed
Alternative
Enable
reset
Door
open,
howeveractuator
breaks
and
stays in
the
position
switch
HINGED_SW Door
open,
ACTUATOR "Machine"rotates
„Machine“
stops
ACT_PAS Slowing
down
movement
"Machine"
in
standstill
COIL Door locked Door unlocked
Door
closed
Stays
reset
Start
request
For
enable,
the door
must be
completely
opened
(error
uncovered)
No start
of the
"machine"
In the case of the principle of interlock by spring force used
here, the safety door remains locked in case of a power failure.
This is the reason why professional associations prefer
spring-actuated lock.
An alternative is the principle according to which the safety
door remains closed due to magnetic force. A voltage must be
applied to the magnet of the safety position switch to keep
the door interlocked. This principle is described in the Safety
Integrated Functional example No. 3 „Safety Door with Magnetic
Engagement in Category 4 acc. to EN 954-1“.