×

Single line multiplexing system for sensors and actuators

  • US 4,311,986 A
  • Filed: 09/13/1978
  • Issued: 01/19/1982
  • Est. Priority Date: 09/13/1978
  • Status: Expired due to Term
First Claim
Patent Images

1. A system for transmitting signals between a processor and at least one remotely located device, wherein the processor generates a plurality of command signals uniquely identifying each of the remotely located device, comprising:

  • a bi-directional data transmission line;

    interrogation signal generating means interconnecting the processor with said data transmission line for generating on said data transmission line interrogation signals having pulse widths ti, the pulse width of each of said interrogation signal is uniquely associated with a corresponding command signal;

    interface means interconnecting each remotely located device with the data transmission line for selectively enabling communication between the processor and said device in response to said interrogation signals, each interface means responsive to an interrogation signal including one of said predetermined pulse widths which is different from the predetermined pulse width to which other interface means respond;

    wherein each of said interface means includes;

    a pulse width discriminator for generating a trigger signal in response to an interrogation signal having a predetermined pulse width;

    means responsive to said trigger signal for establishing direct communication between the device and said transmission line, andwherein the predetermined pulse width of said interrogation signal has a time duration t1, said pulse width discriminator comprises;

    first means responsive to the beginning of each interrogation signal appearing on said transmission line, for generating a first test pulse of duration (ti

    );

    second means, responsive to the termination of said first test pulse for generating a second test pulse having a duration 2Δ

    where 2Δ

    corresponds to a time increment smaller than t1 ; and

    third means, responsive to said interrogation signals and said second test pulse, for generating a trigger signal indicative of the condition that said interrogation signal of duration ti has terminated during the time of said second test pulse.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×