Siemens SIMATIC PCS 7 Operating Manual page 91

Extract from a chart for shutdown group 1 with send block:
The connection to shutdown group 2 is established by linking output S_DB of block
F_S_BO_1 in shutdown group 1 with input S_DB on block F_R_BO_1 in shutdown group 2.
Extract from a chart for shutdown group 2 with receive block:
See also
Monitoring times and system response times (Page 133)
Compendium Part B - Process Safety (V8.2)
Operating Manual, 07/2016, A5E35031794-AB
Configuring the safety program
7.2 Creating the safety program
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