On-vehicle data communication system and method

• US 6,021,308 A
• Filed: 06/18/1997
• Issued: 02/01/2000
• Est. Priority Date: 10/20/1994
• Status: Expired due to Term

• Current Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Original Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Inventors: Kimura, Toshiyuki
• Primary Examiner(s): FLYNN, NATHAN J
• Application Number:
  US08/878,287
• Time in Patent Office: 958 Days
• Field of Search: 348/6, 348/7, 348/8, 348/9, 348/10, 348/11, 348/12, 348/420, 348/476, 348/567, 348/909
• US Class Current: 725/75
• CPC Class Codes: H04B 1/205 with control bus for exchanging commands between units
• CPC Class Codes: H04H 20/62 for transportation systems, e.g. in vehicles
• CPC Class Codes: H04H 20/82 using signals not modulated onto a carrier
• CPC Class Codes: H04H 60/80 characterised by transmission among terminal devices
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04N 7/106 for domestic distribution
• CPC Class Codes: H04N 7/108 the cable being constituted by a pair of wires
• CPC Class Codes: H04N 7/16 Analogue secrecy systems; Analogue subscription systems
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal

Abstract

An on-vehicle data communication system is provided with at least one master unit, a plurality of slave units and a communication bus. Each of the slave units is provided with: a first receiving device for receiving broadcast communication data through the communication bus; a first judgement device for judging whether or not the first receiving device failed to normally receive the broadcast communication data; and a first transmission device for transmitting acknowledge data to indicate a failure in reception of the first receiving device, if the first judgement device judges that the first receiving device failed to normally receive. The master unit is provided with: a second transmission device for transmitting the broadcast communication data to the slave units; a second receiving device for receiving the transmitted acknowledge data; a second judgement device for judging whether or not the acknowledge data corresponding to the transmitted broadcast communication data are received by the second receiving device; and a process control device for performing a predetermined process to cope with the failure of the first receiving device.

Claims

1. An on-vehicle data communication system comprising at least one master unit, a plurality of slave units and a communication bus for connecting said master unit with said slave units, said system performing a broadcast communication, in which said master unit simultaneously transmits first communication data to all of said slave units, and an ordinary communication, in which said master unit transmits second communication data to specific one of said slave units,

each of said slave units comprising:

a first receiving means for receiving said first communication data through said communication bus in case of said broadcast communication, and for receiving said second communication data through said communication bus in case of said ordinary communication; and

a first transmission means for transmitting first acknowledge data to indicate a failure in reception of said first receiving means if said first receiving means fails to normally receive said first communication data in case of said broadcast communication, and for transmitting second acknowledge data to indicate a success in reception of said first receiving means if said first receiving means normally receives said second communication data in case of said ordinary communication,

said master unit comprising;

a second transmission means for transmitting said first communication data to all of said slave units in case of broadcast communication, and for transmitting said second communication data to said specific one of said slave units in case of said ordinary communication;

a second receiving means for receiving said transmitted first acknowledge data in case of said broadcast communication, and for receiving said transmitted second acknowledge data in case of said ordinary communication; and

a process control means for performing a first predetermined process to cope with the failure of said first receiving means if said second receiving means receives said first acknowledge data corresponding to said transmitted first communication data in case of said broadcast communication, and for performing a second predetermined process to cope with a failure of said first receiving means if said second receiving means fails to receive said second acknowledge data corresponding to said transmitted second communication data in case of said ordinary communication.

2. An on-vehicle data communication system according to claim 1, wherein:

each of said first communication data and said second communication data comprise a data block of control data and a data block of substantial data; and

said process control means controls said second transmission means to transmit said data block of substantial data of said first communication data again as said first predetermined process if said second receiving means receives said first acknowledge data while said data block of substantial data of said first communication data are transmitted in case of said broadcast communication, and controls said second transmission means to transmit said data block of substantial data of said second communication data again as said second predetermined process if said second receiving means fails to receive said second acknowledge data while said data block of substantial data of second communication data are transmitted in case of said ordinary communication.

3. An on-vehicle communication system according to claim 1, wherein each of said first communication data and said second communication data have data to differentiate said first communication data and said second communication data from each other.

4. An on-vehicle communication system according to claim 1, wherein each of said master unit and said slave units comprises a controller for each on-vehicle audiovisual component.

5. A method of communicating data in an on-vehicle data communication system comprising at least one master unit, a plurality of slave units and a communication bus for connecting said master unit with said slave units, said system performing a broadcast comnmunication, in which said master unit simultaneously transmits first communication data to all of said slave units, and an ordinary communication, in which said master unit transmits second communication data to specific one of said slave units, said method comprising the steps of:

firstly transmitting said first communication data from said master unit to all of said slave units in case of broadcast communication, and transmitting said second communication data from said master unit to said specific one of said slave units in case of said ordinary communication;

firstly receiving said transmitted first communication data through said communication bus by each of said slave units in case of said broadcast communication, and receiving said transmitted second communication data through said communication bus by said specific one of said slave units in case of said ordinary communication;

secondly transmitting first acknowledge data to indicate a failure in reception of at least one of said slave units if at least said one of said slave units fails to normally receive said transmitted first communication data in case of said broadcast communication in said firstly receiving step, and transmitting second acknowledge data to indicate a success in reception of said specific one of said slave units if said specific one of said slave units normally receives said transmitted second communication data in case of said ordinary communication in said firstly receiving step;

secondly receiving said transmitted first acknowledge data by said master unit in case of said broadcast communication, and receiving said transmitted second acknowledge data by master unit in case of said ordinary communication; and

performing a first predetermined process to cope with the failure in said firstly receiving step if said master unit receives said first acknowledge data corresponding to said transmitted first communication data in case of said broadcast communication in said second receiving step, and performing a second predetermined process to cope with a failure in said firstly receiving step if said master units fails to receive said second acknowledge data corresponding to said transmitted second communication data in case of said ordinary communication in said second receiving step.

6. A method according to claim 5, wherein:

each of said first communication data and said second communication data comprise a data block of control data and a data block of substantial data; and

in said performing step, said data block of substantial data of said first communication data are transmitted again as said first predetermined process if said master unit receives said first acknowledge data while said data block of substantial data of said first communication data are transmitted in case of said broadcast communication in said secondly receiving step, and said data block of substantial data of said second communication data are transmitted again as said second predetermined process if said master unit fails to receive said second acknowledge data while said data block of substantial data of second communication data are transmitted in case of said ordinary communication in said secondly receiving step.