Terminal communications circuit

摘要

A terminal communications circuit that provides communication through a bus interface circuit to a network bus in accordance with the predetermined communications procedure, the terminal communications circuit including a communications interchange circuit that exchanges protocol signals with the bus interface circuit in response to commands received from a signal state controller that is resident in the terminal. The communications interchange circuit further provides communications state change information to the signal state controller to indicate the contents of the protocol signals from the bus information circuit. The signal state controller executes one of a plurality of program states to control communications over the network bus in accordance with predetermined communications procedure by providing commands to the communications interchange circuit in acordance with the program state that the signal state controller is currently executing. The signal state controller changes the program state in response to the communications state change information from the communications interchange circuit. Also provided is a single command from the signal state controller to the communications interchange circuit that results in the communications interchange circuit providing a multiple of individual protocol signal patterns to the bus interface circuit enabling multiple communications procedures to be performed on the communications network with a single command from the signal state controller.