Safety Integrated - Industry - Siemens

The sample code with the given configurations enables the
following:
■ Resetting a failsafe digital output after actuating the emergency
stop push button
■ Renewed setting (= start of the application) of the failsafe
digital output requires the following:
1. User acknowledgement (does not automatically start
the application)
2. Starting the application (only possible in case of previous
acknowledgement)
Program procedure
FC "START_AND_STOP" (FC10)
The (non-failsafe) FC "START_AND_STOP" (FC 10) is called
from OB 1 (see following figure).
...
"START"
"STOP"
EN
START
STOP
"START_AND_STOP"
Parameter Adress Explanation
COND
ENO
"COND"
START E 0.1 Push button (NO) for the start requirement.
STOP M 90.5 Dummy. If the operation related stop
is to be implemented, replace the
memory bit by an input Ex.y.
COND M 90.0 Saves the information start/ stop of
the "machine".
The information of the memory bit "COND" is read as memory
bit COND1 in the safety program. This allocation occurs in the
cyclic interrupt OB35 for the following reason:
When reading data, which may be changed by the standard
user program or an operation control and monitoring system
during running of an F runtime group, from the standard user
program (memory bits or PAE of standard I/O), in the safety
program, it is necessary to use separate memory bits (here
COND1). Data from the standard user program have to be
written to these memory bits immediately before calling the F
runtime group. Only these memory bits may then be accessed
in the safety program.
G_FB_XX_078
In this example it has already been implemented. Generally,
however, the following applies:
Note
If the above section is not observed the F CPU may go to
STOP mode.
The FC "START_AND_STOP" (FC 10) in the following figure
sets/resets #COND whose signal status ("0" or "1") starts or
stops the "machine" in the failsafe program. #COND can only
become "1" if the emergency stop button has been unlocked
and acknowledged prior to the start (occurs in the safety program).
This is ensured by the "Instanz_FB1".EN_ESTP bit from
the instance data block DB 1 of FB 1 (from the safety program).
This bit must have been set for a possible start. If this
bit is "0" the "1" signal lies at the R entry of the flipflop, which
makes the output Q always "0", even if with #START the S entry
receives the "1" signal (resetting has priority with the used
flipflop).
#START
#STOP
"INSTANZ_
FB1".
EN_ESTP
"P" "SR"
P
SR
>=1
#COND
=
The failsafe program has the following program sequence:
F-Call
(FC1)
Functional Example No. AS-FE-I-001-V10-EN 177
S
FC"COORDINATION"
(FC2)
R Q
FB"ESTOP"
(FB1,DB1)
FC"REINTEGRATION"
(FC3)
G_FB_XX_079
G_FB_XX_080
Ex. No.
1