Host initiated state control of remote client in communications system

摘要

A system and method for low-cost, fault tolerant, EMI robust data communications, particularly for an EV environment. A data communications method, including a) enabling a transmission of a wake signal from a host to a remote client through an isolator disposed at the remote client when the wake signal is asserted from the host at a host-portion of the isolator concurrent with a periodic enablement of a client-portion of the isolator by the remote client; and thereafter b) transmitting the wake signal from the host to the remote client through the isolator; c) controlling enablement of the client-portion responsive to the wake signal transmitted through the isolator; and thereafter d) disabling the transmission by deassertion of the wake signal at the host.

主权项

1. A data communications system, comprising:
a host including a power supply providing a supply voltage over a supply voltage line and a reference voltage over a reference voltage line with said host selectively enabling a particular one voltage line when asserting a wake signal; a client including a plurality of electrical components and an isolator disposed between said plurality of electrical components and said host, said isolator including a client portion, a host portion, and a plurality of isolator channels with said isolator having an active mode and an inactive mode wherein said active mode enables a transmission from a channel input port to a channel output port of each said isolator channel when both said client portion and said host portion are enabled and wherein said inactive mode disables said transmissions of said isolator channels when either said client portion or said host portion are non-enabled, said plurality of isolator channels including a wake channel having said channel input port coupled to said particular one voltage line with said host portion enabled whenever said wake signal is asserted; wherein said plurality of electrical components include a wake-control system, coupled to said channel output port of said wake channel, periodically enabling said client portion to test a state of said wake signal with said wake-control system maintaining said client portion enabled as long as said wake signal is asserted, wherein said wake-control system includes a pulse generator periodically generating a polling signal, a logic-OR element having a first input coupled to said pulse generator receiving said polling signal, a second input coupled to said channel output port of said wake channel, and an output coupled to an enable control of said client portion of said isolator.