Electrical device command system, single wire bus and smart single controller arrangement therefor

• US 4,920,532 A
• Filed: 12/07/1988
• Issued: 04/24/1990
• Est. Priority Date: 12/07/1988
• Status: Expired due to Term

• Current Assignee: Chrysler LLC (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Wroblewski, Thomas R.
• Primary Examiner(s): Olms, Douglas W.
• Application Number:
  US07/280,917
• Time in Patent Office: 503 Days
• Field of Search: 370/85, 370/94, 370/89, 370/96, 370/90, 370/24, 340/825.5, 340/825.51, 340/825.52, 340/425.5
• US Class Current: 370/276
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: H04J 3/26 in which the information and the address are simultaneously transmitted

Abstract

A multiplex system for addressing, commanding and monitoring the status of a plurality of electrical devices disposed throughout a motor vehicle. A dual-duty cycle type voltage waveform generated by a microcomputer provides address signals for enabling individual controllers connected to a bi-directional single wire bus coupled at one end to a driver and receiver circuit of the microcomputer. After the individual controller is addressed, another portion of the waveform provides information for operating the electrical device in response to a polarity control data bit portion of the same voltage signal to turn the connected element either ON or OFF. Circuits within the addressed controller provides current signal indicative of the ON or OFF statues of the electrical device.

Claims

1. A multiplex system within a motor vehicle for commanding and monitoring the status of a plurality of electrical devices or elements disposed throughout the motor vehicle, each of the elements having command terminals for receiving commands in the form of a discrete voltage signal for activating or deactivating each of the elements, one of the command terminals also being used to provide a status indication of each of the elements in the form of a current signal upon being commanded, said system comprising:

(a) a bi-directional, single wire bus for transmitting in a first direction a series of square wave double duty cycle voltage signals used for commanding ON or OFF the plurality of elements and for transmitting in a second direction, a series of current signals used for indicating the ON or OFF status of the plurality of elements;

(b) a plurality of smart single controllers disposed throughout the motor vehicle, each one of said single controllers being disposed near one of the elements for commanding the element ON or OFF, each one of said single controllers having;

1. a single input/output terminal connected by a single wire to a single point along said bus for receiving the square-wave voltage signal;

2. integration means for converting the square-wave voltage signal into a dual-amplitude, sawtooth-pulse waveform containing address and data information wherein a first amplitude pulse represents LOW bit and a second amplitude pulse represents HIGH bits;

3. detection means for detecting an address code of said sawtooth-pulse waveform in order to enable said single controller to command the accompanying element when the detected address code matches a preprogrammed address of said single controller;

4. means for detecting a data bit code from said sawtooth-pulse waveform in order to determine whether to turn ON or OFF the accompanying element;

5. means for commanding the accompanying element ON or OFF, said commanding means including means for transmitting a current signal back over said bus indicative of the status of the element after commanding the element ON or OFF;

c. a driver and receiver means, receiving power from a power source of the vehicle and connected to said single-wire bus, for generating the series of square-wave, double-duty cycle voltage signals used by each of said single controllers;

said driver and receiver means also including means for receiving the status of the elements indicating current signals transmitted over said bus;

d. display means for displaying the status of the plurality of elements; and

e. a microcomputer means interconnecting said driver and receiver means and said display means for (1) writing logic commands to said driver and receiver means for controlling the generating of the series of square-wave, double-duty cycle voltage signals used for placing address and command information on said bus;

(2) reading the current signals indicative of the status of the commanded element;

(3) establishing a history of performance of each of the commanded elements; and

(4) transferring updated status information to said display means.

2. Apparatus in accordance with claim 1 wherein each of the series of square-wave voltage signals contain five independent duty-cycle, address pulse signals, and a data pulse signal, the five address pulses being used to address one of said single controllers by matching the predetermined address fixedly assigned to said single controller and to enable said addressed single controller to command ON or OFF, with a voltage signal, the accompanying element, and the data pulse being used to determine the polarity of the command voltage signal going to the accompanying element.

3. Apparatus in accordance with claim 2 wherein said single controller includes:

(1) means for converting said address and command pulses into address and command binary bits;

(2) means for detecting said address and data bits;

(3) means for providing an acknowledgement to said microcomputer of the addressing of said single controller;

(4) means for commanding the accompanying element ON or OFF in response to the polarity of the detected data bit; and

(5) means for detecting a status indicating current signal from the commanded element and then transmitting the current signal over said bus to said driver and receiver means.

4. In a vehicle multiplex system for both controlling and monitoring the status of a plurality of electrical devices or elements disposed throughout the motor vehicle, the elements containing control and status indication terminals, the system comprising:

a. microcomputer means having a predetermined program which controls addressing, commanding and monitoring the system and which produces therefrom a series of logic signals from at least a pair of output ports that represent the address and command information needed for operating the plurality of elements;

b. driver and receiver means adapted to receive the series of logic signals from said microcomputer means and to selectively convert the series of input logic signals into a series of dual-duty cycle output voltage signals of a chosen format containing address and data information needed to operate the plurality of elements;

c. a bi-directional, single wire bus connected to the driver and receiver means at one end for transmitting the voltage signals in a first direction needed to operate the plurality of elements and for transmitting status information concerning the operated element in the form of a current signal from the element in a second direction, said bus being routed throughout the vehicle; and

d. a plurality of single controllers, each of which being connected at an output end to one of the plurality of elements so as to permit commanding ON or OFF the connected element and to permit obtaining a current signal from the connected element indicative of the operational status, each of said plurality of single controllers having means for (a) forming a single point input connection with said bus and for (b) forming a power connection across a vehicle battery to receive battery power;

each of said plurality of single controllers having a preprogrammed address which must match the address information in order to address one of said plurality of single controllers, after being addressed, said addressed controller returning an acknowledgement signal back to said driver and receiver circuit, said addressed controller using a voltage command of a polarity indicated by the data information contained in the series of dual-duty cycle voltage signals for turning ON or OFF the connected element;

each of said plurality of controllers also containing circuits responsive to status signals emanating from the status indication terminals of the connected element.

5. Apparatus in accordance with claim 4 wherein said microcomputer means includes means for reading the status information of each commanded element transferred by said addressed controller, and wherein said microcomputer means also includes means for transferring the status information to said display means for display.