A new whitepaper about cybersecurity on DeltaV process safety systems is available. This whitepaper can help you in understanding and developing a coordinated cybersecure architecture between a safety instrumented system (SIS) and the Basic Process Control System (BPCS). Key among those considerations is that protection against cybersecurity threats on safety systems should not depend solely on architecture considerations (interfaced SIS vs integrated SIS).
To download this white paper, go here:
http://www.emerson.com/documents/automation/1262078.pdf