MULTIPLEXED CURRENT LOOPS FOR ANALOG DATA TRANSMISSION
Original Publication Date: 1992-Apr-30
Included in the Prior Art Database: 2004-Apr-05
Xerox Disclosure Journal
Traditionally, the transmission of analog signals within copier/duplicator environments has resulted in problems, due to the susceptibility of the analog signals to noise. With the use of numerous high voltage and switching power supplies within such systems, the presence of this problem is not unexpected. The noise problem lead to a consideration of current loops for the transmission of analog signals within the copiers, as these techniques are frequently used in factory environments where the same electronic noise sources are generally present. However, the typical current loop system requires at least two signal wires from the controller for each input and an additional two wires for power, resulting in a total of four wires for each output or remote transceiver. Hence, the cost of such a system is relatively high, given the need for the large number of wires, in addition to the line drivers or receivers associated with each wire. Overcoming the rather large hardware requirement for each transceiver would reduce the overall cost of such a system.