Communication Options
3.6 Safety-Related CPU-CPU Communication
Safety Engineering in SIMATIC S7
3-14
System Manual, 04/2006, A5E00109529-05
Communication Overview
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Figure 3-7
S7 Distributed Safety: Safety-related master-master communication
Master-Master Communication
Safety-related communication takes place with the aid of two fail-safe application blocks: the
F_SENDDP block for sending data and the F_RCVDP block for receiving data. These blocks
are called by the user in the respective safety program of the F-CPU. They can be used to
transfer a fixed number of fail-safe data of data types BOOL and INT in a fail-safe manner.
Required User Steps
The user performs the following steps for safety-related master-master communication:
1. Set up hardware with a DP/DP coupler
2. Configure the DP/DP coupler in
HW Config
3. Call F_SENDDP and F_RCVDP from the
Distributed Safety F-library in the safety
program of the respective F-CPU
4. Assign parameters for F_SENDDPs and F_RCVDPs
5. Once the safety programs have been created, compile and download them to the
appropriate F-CPU
Additional Information
For information on the DP/DP coupler, refer to the documentation for the DP/DP coupler and
the
SIMATIC NET, PROFIBUS Networks manual. For detailed information on configuring
and programming safety-related
master-master communication, refer to the
S7 Distributed Safety Configuring and
Programming manual.
See also
Structure of the Safety Program in S7 Distributed Safety (Page 7-4)
