A data communications system in an electrically noisy environment, comprising: a plurality of communication devices, said communication devices including a host and a number N of clients, N greater than 1, communicated to said host using a first unidirectional daisy-chain loop wherein said first unidirectional daisy-chain loop originates and terminates at said host and wherein said first unidirectional daisy chain-loop comprises a number N+1 of conductor segments, each particular one conductor segment of said first unidirectional daisy-chain loop communicating an upstream communications device to a downstream communications device; characterized in that each communications device includes a printed circuit board, PCB, having a connector with a plurality of electrical couplers, a plurality of PCB components, and a plurality of traces (325, 330) communicating said plurality of electrical couplers to one or more of said plurality of PCB components, and wherein a particular one conductor segment of said first unidirectional daisy-chain loop joins a first particular one coupler of said connector of said upstream communications device to a first particular one coupler of said connector of said downstream communications device, wherein said plurality of PCB components includes a data processing system and wherein each said PCB includes an isolator electrically disposed between said connector and said data processing system and wherein for each particular PCB said isolator includes a plurality of isolator channels, one isolator channel associated with each coupler of said plurality of couplers of said connector, and wherein the electrically noisy environment includes an electric vehicle including an electric propulsion motor generating a time-varying magnetic field, said electric vehicle having an energy storage system that includes a management system and a battery pack comprised of said number N of inter-coupled battery modules with said host associated with said management system and each said client associated with one of said inter-coupled battery modules and wherein each said PCB includes an electrical interface, said electrical interface electrically communicating said PCB to said associated battery module. a plurality of communication devices, said communication devices including a host and a number N of clients, N greater than 1, communicated to said host using a first unidirectional daisy-chain loop wherein said first unidirectional daisy-chain loop originates and terminates at said host and wherein said first unidirectional daisy chain-loop comprises a number N+1 of conductor segments, each particular one conductor segment of said first unidirectional daisy-chain loop communicating an upstream communications device to a downstream communications device; each communications device includes a printed circuit board, PCB, having a connector with a plurality of electrical couplers, a plurality of PCB components, and a plurality of traces (325, 330) communicating said plurality of electrical couplers to one or more of said plurality of PCB components, and wherein a particular one conductor segment of said first unidirectional daisy-chain loop joins a first particular one coupler of said connector of said upstream communications device to a first particular one coupler of said connector of said downstream communications device, wherein said plurality of PCB components includes a data processing system and wherein each said PCB includes an isolator electrically disposed between said connector and said data processing system and wherein for each particular PCB said isolator includes a plurality of isolator channels, one isolator channel associated with each coupler of said plurality of couplers of said connector, and wherein the electrically noisy environment includes an electric vehicle including an electric propulsion motor generating a time-varying magnetic field, said electric vehicle having an energy storage system that includes a management system and a battery pack comprised of said number N of inter-coupled battery modules with said host associated with said management system and each said client associated with one of said inter-coupled battery modules and wherein each said PCB includes an electrical interface, said electrical interface electrically communicating said PCB to said associated battery module.