This was initially proposed as a talk on vulnerabilities Alexander's research had found in the more than 100 DTM components. The DTM provides a unified structure for accessing field device parameters, configuring and operating the field devices, and diagnosing problems. Mostly, DTMs are COM, ActiveXor .Net components. And you will still see a lot of vulns. However, identifying basic security flaws is no longer an S4 topic. After further discussion we found that Alexander's techniques for efficiently testing the DTM components and the developed tools that solved a number of testing problems would be highly interesting to the S4 attendee. He will show the path through his research. From planning fuzzing infrastructure and developing new tools, to proof-of-concept exploit development. He will discuss how Alexander and his fellow researchers evaded or solved the testing problems. Finally, he will present some new tools for DTM component security assessments.