These industry giants —ABB , Siemens , Endress Hauser, and Fisher Controls —represent vital forces in the process sector . While all offer extensive portfolios of systems, their focus areas differ. https://rosemountcx2100dr03a206n209214.wannawiki.com/1553913/abb_siemens_endress_hauser_and_emerson_s_fisher_division_a_comparative_review