Safety Integrated - Industry - Siemens

Ex. No.
6
Emergency stop
Pressing the emergency stop push button resets the indicator
light (simulated stop of the "machine"). Prior to a restart of the
"machine" start it is required to unlock and acknowledge the
emergency stop push button.
Flowchart
The flowchart below once again illustrates the relations.
Parametrized in the
hardware configuration of
STEP 7
Programmed in the safety
program of STEP 7
N Was machine
in RUN?
Y
"Machine" in STOP
Time sequence
Die in der nachfolgenden Tabelle genannten Zeiten werden
im weiteren in einem Zeitdiagramm gezeigt.
Time Explanation Note
∆t1 Discrepancy time between
make contact and
break contact at exclusive
OR sensor 1
∆t2 Discrepancy time between
make contact and
break contact at exclusive
OR sensor 2
∆t3 Discrepancy time between
exclusive OR sensor
1 and 2
N
Y
N
Parameterized in the hardware
configuration of STEP 7.
Programmed in the failsafe F
program of STEP 7.
t1 Start of the "machine" Simulated by indicator light.
Start
First start?
Emergency
stop tripped?
Discrepancy time
exceeded between make
contact and break
contact?
Both exclusive OR
sensors pressed?
Y
Diskrepanzzeitüberschreitung
zwischen
Antivalentsensor 1
und 2?
N
"Machine" in RUN
End runtime
"Machine"?
"Machine" in STOP
Acknowledgement?
234 Functional Example No. AS-FE-I-006-V10-EN
N
N
N
Y
Y
Y
Y
Y
N
"Machine" in STOP
Acknowledgement?
Y
N
The runtime of the
"machine" is
simulated by a
constant time during
which the indicator
light is ON.
G_FB_XX_134
Time Explanation Note
t2 Stop of the "machine" Possible reasons:
■ End of "machine time"
■ At least one exclusive OR
sensor was released
■ Emergency stop was actuated
■ Passivation of the failsafe
input module of ET 200S
(F-DI)
Exclusive OR
sensor 1
Make contact 1
Exclusive OR
sensor 1
Break contact 1
Exclusive OR
sensor 2
Make contact
Exclusive OR
sensor 2
Break contact
"Machine"
1
1
1
Advantages/customer benefits
t1
t3
t3
t1 t2
■ Wiring reduced to a minimum due to use of failsafe S7-CPU
and distributed I/O. The more safety functions are implemented,
the more useful this advantage is.
■ Programming the failsafe program with STEP 7 engineering
tools.
■ Only one CPU is required since failsafe and standard program
parts run on a coexistent basis in the CPU.
■ Use of prefabricated (and certified) failsafe blocks from the
Distributed Safety library.
■ Design of the two-hand control with integrated control
devices including emergency stop.
■ Additional control devices can be mounted.
■ All relevant standards are complied with.
■ The metal version of the two-hand control is also suitable for
harsh industrial conditions.
t
t
t
t
t
G_FB_XX_135