Interfacing Safety Instrumented Systems (SID)

sinha,

I understand from your comment that , HIPPS and ESD are in separate systems.You will be interfacing the both , only when u r in need of exchanging the tags between the two systems.The impact between each systems depends on the program, like fails states u implement.If it is a crucial tag and u dont want to take risk bcoz of communication failure, u can also go for hardwire.

Strictly speaking this can defeat independence. Careful engineering at the interface between HIPPS, &ESD and your combining system can mitigate this to an acceptable level though.