System for defining data transmission protocols in a multiplexing system
AssigneeThe Whitaker Corporation
InventorsKeith J. McKechnie, Lee W. Steely, Paul S. Chang
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Abstract
A system for defining and controlling data transmissions in a multiplexing system having a host controller in bi-directional communication with a plurality of remote stations or nodes. The system includes a series of simple frame flags generally defined as varying periods of inactivity on the bi-directional transmission line.
Claims6
In a data transmission system including a control unit, a plurality of remote stations, a bi-directional transmission line, and means for coupling said control unit and said plurality of remote stations to said transmission line, wherein the control unit sends data to an addressed One of said plurality of remote stations in the form of a first group of data digits each having a defined bit sequence
- apparatus in each of the remote stations comprising:
- means for receiving signals on the transmission line;
- means for validating the received signals as valid data digits when the received signals have the defined bit sequence of each data digit;
- first detecting means for detecting a first period of inactivity during which no valid data digits are received on the transmission line;
- means responsive to detection of said first period of inactivity for thereafter accepting data on the transmission line and determining whether said each of the remote stations has been addressed by the control unit;
- second detecting means for detecting a second period of inactivity during which no valid data digits are received on the transmission line, said second period having a duration different from the duration of said first period of inactivity;
- and
- means responsive to detection of said second period of inactivity when said each of the remote stations has been addressed for thereafter transmitting data to the control unit in the form of a second group of data digits each having said defined bit sequence.
Dependencies are inferred from the claim text.