Allowable F Control Block Comparison Changes - Siemens SIMATIC S7 F Manual

Programming
Procedure
To compare two Safety Programs, proceed as follows:
1. Select the program folder (e.g. "S7 Program") in SIMATIC Manager.
2. Choose the Options > Edit Safety Program menu command. The "Safety
Program – S7 Program" dialog box appears.
3. Select the "Compare..." button. The "Compare Programs" dialog box appears.
4. Select the programs you want to compare. If necessary, use the "Browse..."
button to enter the path.
5. Select the "Start" button.
The result is displayed in a dialog box at block or chart level and can be printed out
using the "Print" button. The signatures of the individual blocks are displayed in the
block view. The changes to charts, blocks and run-time groups are displayed in the
chart view. You can also see here if the signatures of the F-Blocks have changed.
Safety Note – Allowable F Control Block comparison changes
!
At the F_CNT_W input of the F_TESTC block, the number of F code blocks (FB
and run-time group FC) in working memory is displayed. If changes are made to
the Safety Program, changes to this parameter can be expected in the section of
the program that has already been accepted.
The differences in the chart comparison of the following block I/Os can be ignored
because they are due to internal changes in the Safety Program. These changes
can be caused, for example, by compressing the data blocks in CFC.
The overall signature still changes, of course, and differences must be taken into
consideration at acceptance.
The overall signature is visible at the F_SHUTDN function block's F_PRG_SIG
input.
Fail-Safe Systems
A5E00085588-03
Block I/O
F_TESTC TESTM_DB, CYC_DB
F_PLK SIG, SIG_I, CYC_DB, TEST_DB, TESTC_DB,
TESTM_DB
F_PLK_O SIG_O, SIG_O_I
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