Several thousand multi-vendor installations worldwide have proven the interoperability of SERCOS controls, drives and I/Os. This provides impressive evidence that SERCOS is a stable and accepted technology. Although the SERCOS interface has been improved with new functions and better performance over the years, the SERCOS protocol has remained compatible since the very beginning. Thus, even devices from the first generation in the early 90s are able to communicate with new generation SERCOS products. In 2001 SERCOS International introduced a new conformance test based on the SERCOS Conformizer. This powerful test detects even small incompatibilities in master & slave implementations. Many companies are already using the SERCOS Conformizer as a pre-test tool for quality assurance and intend to undergo the official conformance test in the authorized testing laboratories in the near future.  Here is a list of SERCOS I/II devices that have successfully passed the new Conformance Test.