Siemens SIMATIC PCS 7 Operating Manual page 98

Configuring the safety program
7.3 Configuring fail-safe AS-AS communication
Procedure
Follow the steps outlined below:
1. Add the send block (F_SENDBO/F_SENDR) to the safety program from which data is to
be transmitted.
2. Add the receive block (F_RCVBO/F_RCVR) to the safety program to which data is to be
transmitted.
3. Assign the relevant IDs of the configured S7 connections to the "ID" inputs.
4. Configure the R_ID inputs. This defines the relationship between a send block and a
receive block:
The associated fail-safe blocks are assigned the same (freely selectable, uneven value
for R_ID. Please note that the R_ID+1 value is also assigned automatically.
Example: Local AS4 is sender, partner AS3 is recipient
98
Compendium Part B - Process Safety (V8.2)
Operating Manual, 07/2016, A5E35031794-AB