Safety Integrated - Industry - Siemens

Ex. No.
9 Flowchart
The following flow chart shows the functionality at the example
of group 1 (motor M1) and the group shutdown. The same
procedure applies to group 2 (motor M2); only M1 and M2
need to be exchanged and K1, K2 be replaced with K3, K4.
N
N
N
J
N
Start
M1 running?
Common emergency
stop unlocked?
J
Emergency stop1
unlocked?
J
Readback signal K1
and K2 OK?
J
Acknowledgement
necessary?
N
Start command M1?
J
M1 starts
J
Common emergency
stop unlocked?
Time sequence for single/group shutdown
To illustrate the process, the time sequence during a single
and a group shutdown is shown below. The names at the ordinates
correspond to the names in the program code.
Designation Explanation
START_M1 Start command for motor 1 (group 1).
START_M2 Start command for motor 2 (group 2).
ACK_ALL Acknowledgement for all groups
ESTP1 Emergency stop for motor M1 (group 1)
ESTP2 Emergency stop for motor M2 (group 2)
ESTP_ALL Emergency stop for all groups
M1 Motor 1 (group 1)
M2 Motor 2 (group 2)
278 Functional Example No. AS-FE-I-009-V10-EN
J
Emergency stop1
unlocked?
J
N
N
M2 stops
J
Readback signal K1
and K2 OK?
N
Time
t1 t2 t3
Explanation
t4 t5 t6 t7 t8 t9 t10
M1 stops
G_FB_XX_083
START_M1
(NO)
START_M2
(NO)
G_FB_XX_164
ACK_ALL
(NO)
ESTP1
(NC)
ESTP2
(NC)
ESTP_ALL
(NC)
M1
M2
t1 An acknowledgement is required before starting for the
first time.
t2 Start command for motor M1. Motor M1 starts.
t3 Start command for motor M2. Motor M2 starts.
t4 Emergency stop triggered for group 1 Motor M1 stops.
t5 Emergency stop triggered for group 2 Motor M2 stops.
t6 Unlocking both pressed emergency stop buttons.
t7 Acknowledgement is necessary prior to every restart.
t8 Start command for motor M1. Motor M1 starts.
t9 Start command for motor M2. Motor M2 starts.
t10 Emergency stop, applying to all groups, is activated and
switches all groups off.
Note
Apart from the acknowledge button applying to all
groups, each group as a respective acknowledge button
(not displayed in the above time sequence).
Advantages/customer benefits
■ Wiring reduced to a minimum due to use of failsafe S7-CPU
and distributed I/O. Dieser Vorteil kommt um so mehr zum
Tragen, je mehr Sicherheitsfunktionen realisiert werden.
■ 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.
t
t
t
t
t
t
t
t