Safety Integrated - Industry - Siemens

Ex. No.
7
If you want to read data from the standard user program (flags
or PII of standard I/O) in the safety program (here: COND),
which can be changed by the standard user program or an operator
control and monitoring system during the runtime of
an F run-time group, it is required to use separate flags (here:
COND1). Data from the standard user program have to be
written to these flags immediately before calling the F runtime
group. Only these flags may then be accessed in the
safety program.
This has already been implemented in this example. In general,
however, the following applies
Note
If the above section is not observed the F CPU may go to
STOP mode.
The failsafe program has the following program sequence:
F-CALL
(FC1)
FB"F_PRG"
(FB1,DB1)
FB"F_FDBACK"
(FB216,DB216)
From the
Distributed Safety
library
FC"REINTEGRATION"
(FC2)
F-CALL (FC1)
The obligatory F-CALL (FC 1) is called from the cyclic interrupt
OB (OB 35). This OB calls the F runtime group (here FB 1).
256 Functional Example No. AS-FE-I-007-V10-EN
G_FB_XX_149
FB "F_PRG" (FB 1, DB 1) und FB "F_FDBACK" (FB 216, DB
216)
Network 1
FB "F_PRG" (FB1, DB1) first calls FB "F_FDBACK" (FB216, DB216).
FB 216 is a certified block from the Distributed Safety library; this
block is available from version 5.3.
"ACK"
"ESTP"
#ERROR
#N #EN
N
SR
S
>=1
R Q
"COND1"
&
"FEEDBACK K1"
"F00009_
4_F_DO_
DC24V_
2A".QBAD
"ACK_NEC"
"ACK"
T#100MS
"INSTANZ_
FB216"
"F_FDBACK"
The acknowledgement signal ACK is responsible for the acknowledgement
after activating and unlocking the emergency
stop as well as after exceeding the feedback time
FDB_TIME (on FB 1). The latter is indicated by #ERROR="1".
The status of the flip-flop is stored in the static variable #EN
and read as switch-on condition in OB 1.
"1" signal on the formal parameter ACK_NEC indicates that a
manual acknowledgement is required to set release (formal
parameter Q). The bit #ACK_NEC is a static variable with initial
value "0".
Output Q is set to 1 as soon as input ON = 1. It is required that
readback input FEEDBACK = 1 and no readback error must be
stored.
A readback error ERROR = 1 is detected if the signal state of the
readback input FEEDBACK (to output Q) does not follow the
signal state of the input ON within the maximum tolerable
readback time FDB_TIME. K1_K2 is the bit from the F-output
module, which sets the contactors K1 and K2.
To ensure that no readback error is detected and that no acknowledgement
is required in a passivation of failsafe the I/O
modules controlled by output Q you have to supply the input
QBAD_FIO with the variable QBAD of the corresponding failsafe
I/O module DB.
Note
Before inserting the F application block F_FDBACK, you
have to copy the F application block F_TOF from the
block container F-Application Blocks\Blocks of the F library
Distributed Safety (V1) into the block container of
your S7 program if it is not available in this container
(has already been done in this example project).
EN
ON
FEEDBACK
QBAD_FIO
ACK_NEC
ACK
FDB_TIME
Q "K1_K2"
ERROR #ERROR
ACK_REQ #ACK_REQ
DIAG ...
ENO
G_FB_XX_150