This grant supports the 2nd CPS National Principal Investigators Meeting, held August 1-2, 2011, at the Gaylord National Hotel, National Harbor, Maryland. The purpose of this meeting is to review research progress, enhance research interaction among projects funded under the NSF Cyber-Physical Systems program, and to provide a forum for stakeholders in academia, industry and federal agencies to review new developments in CPS foundations and domains. It provides an opportunity for the CPS community to promote new, emerging applications, and to collectively identify technology gaps and barriers.