A communications system and method are provided for digitally connecting a
plurality of data channels, such as sensors, actuators, and subsystems,
to a controller using a network bus. The network device interface
interprets commands and data received from the controller and polls the
data channels in accordance with these commands. Specifically, the
network device interface receives digital commands and data from the
controller, and based on these commands and data, communicates with the
data channels to either retrieve data in the case of a sensor or send
data to activate an actuator. Data retrieved from the sensor is converted
into digital signals and transmitted to the controller. Network device
interfaces associated with different data channels can coordinate
communications with the other interfaces based on either a transition in
a command message sent by the bus controller or a synchronous clock
signal.