While some may find this as a break thru, it’s what I view as a direction of the industry.  Siemens and other automation suppliers (Emerson, Yokogawa) have introduced and have been offering for several years now, “updated” safety systems, that don’t require redundancy to achieve high levels of safety.  In the past, safety systems required dual, triple or even quadruple redundancy just to achieve high levels of safety.  So what happened?

For starters, you need to have a clear understanding on what this means.  These systems are designing safety into their core design.  They no longer “need” additional hardware to internally compare with in order to achieve high safety levels.  They utilized special designs with dedicated internal circuitry that can provided diagnostic coverage levels that had previously been not conceivable.

These advanced safety designs provide user benefits by increasing safety while allowing redundant architectures to perform the way they were intended to, prevention against nuisance trips.  An additional benefit is that these systems are immune to system degradation where a conventional “voting” system, needed its redundant partner(s) to help provide high safety.

Another common misunderstanding is how these systems address field redundancy (sensors and final control elements).  While I can’t speak for the Emerson or Yokogawa system, I do know for a fact that the new Siemens HART analog input module handles redundant field devices just like any dual, triple or quadruple redundant system would.