Abstract: In a method for superimposed conveyance of data and electrical power, a first switch can cycle to convey the electric power and data from a first device. Binary digits of the data from the first device can be represented by transitions, of a voltage at a node of a second device, between a first voltage and a second voltage. A second switch can cycle to convey data from the second device. Binary digits of the data from the second device can be represented by transitions, of a current through a component of the first device, between being less than a threshold and being greater than the threshold. A voltage regulator of the second device can provide, in response to the voltage at the node being within a range of voltages that includes the first voltage and the second voltage, the electrical power to one or more components.

Abstract: In a method for superimposed conveyance of data and electrical power, a first switch can cycle to convey the electric power and data from a first device. Binary digits of the data from the first device can be represented by transitions, of a voltage at a node of a second device, between a first voltage and a second voltage. A second switch can cycle to convey data from the second device. Binary digits of the data from the second device can be represented by transitions, of a current through a component of the first device, between being less than a threshold and being greater than the threshold. A voltage regulator of the second device can provide, in response to the voltage at the node being within a range of voltages that includes the first voltage and the second voltage, the electrical power to one or more components.

Abstract: A device (100) that includes a communications port (130), a first processor (135), at least a second processor (140), and a multiplexer (105). The multiplexer can selectively communicatively link the communications port to the first processor or the second processor. The multiplexer can include at least one switch (110, 115) and a switch controller (120) that controls operation of the switch. The switch controller can be responsive to at least one control signal (125) generated by the first processor. The first processor can generate the control signal in response to a command received from an external device (155) connected to the communications port. The command can be an attention command or a test software command. The switch controller also can be responsive to at least one control signal generated by the second processor.