Siemens SIMATIC S7 Configuration And Programming Manual page 67

Section 5.3.3, Fully Qualified DB Access
In contrast to the information in the manual, Section 5.3.3 access to F I/O DBs of
the F I/O of which no channel is used in the safety program, does not lead to an
F-CPU STOP. The safety program can be compiled.
Section 5.3.4 to 5.3.7, Signal Chart Figures
The signal charts presented in the "Signal Chart ..." figures in Sections 5.3.4 to
5.3.7 of the manual represent typical signal charts for the indicated behavior.
Actual signal charts and, in particular, the relative position of the status change of
individual signals can deviate from the given signal charts within the scope of
known distortion for cyclic program execution, depending on the following:
•
Type of F I/O used
(F I/O with inputs, F I/O with outputs, F I/O with inputs and outputs, S7-300
F-SMs, ET 200S F-modules, or fail-safe DP standard slaves, version of
PROFIsafe bus profile for the F I/O)
•
Cycle time of OB of safety program
•
Target rotation time of PROFIBUS-DP
Note
The signal charts refer to the status of signals in the user's safety program. If the
signals are evaluated in the standard user program before or after the safety
program is called in the same OB, the status change of the signals can be
displaced by one cycle.
Contrary to what is shown in the status charts, status changes between process
and fail-safe values that are transmitted to the fail-safe outputs ("To Outputs"
signal chart) can occur before the status change of the associated QBAD signal,
if necessary. The timing of the status change is dependent on whether F I/O with
outputs or F I/O with inputs and outputs were used.
Section 5.3.8 omitted
Section 5.4, Programming of Safety-Related Communication by Means of DP/DP
Coupler
Note
A separate instance DP must be used for each call of an F SENDDP or F_RCVDP
block.
Product Information for the S7 Distributed Safety, Configuring and Programming Manual
A5E00169432-02
67