Communication system, communication apparatus and communication method of communication system

• US 8,495,162 B2
• Filed: 06/24/2008
• Issued: 07/23/2013
• Est. Priority Date: 07/10/2007
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Suzuki, Noriyuki
• Primary Examiner(s): Patel, Ashok
• Assistant Examiner(s): GOLDBERG, ANDREW C
• Application Number:
  US12/145,173
• Publication Number:
  US 20090019129A1
• Time in Patent Office: 1,855 Days
• Field of Search: 709/208
• US Class Current: 709/208
• CPC Class Codes: H04N 21/4223 Cameras H04N23/00 takes precedence
• CPC Class Codes: H04N 21/4363 Adapting the video stream to a specific local network, e.g. a Bluetooth® network
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices
• CPC Class Codes: H04N 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A communication system in which a plurality of communication apparatuses and a communication control apparatus are daisy chained. The communication control apparatus transmits control data to the plurality of communication apparatuses, and receives data transmitted by the plurality of communication apparatuses. Each communication apparatus receives data from another communication apparatus on a different side from a communication control apparatus side, in synchronous with receipt of the control data, and transmits data to one of the communication control apparatus and another communication apparatus on the communication control apparatus side, and following the transmission, to transmit data received to the one of the communication control apparatus and the other communication apparatus on the communication control apparatus side, in synchronous with receipt of the control data.

Claims

1. A communication system in which a plurality of communication apparatuses and a communication control apparatus provided in a daisy chain configuration, and each communication apparatus relays data from one side of the communication system to another side, wherein

the communication control apparatus comprises:

a transmission unit to transmit, to the plurality of communication apparatuses, a command message comprising a plurality of command fields, each of the command fields having a command code and a parameter code, each of said command codes including respective operation delay information for each communication apparatus; and

a reception unit to receive communication data transmitted by the plurality of communication apparatuses, and

each communication apparatus comprises;

a command reception unit to receive the command message from an upstream side of the daisy chain configuration;

a communication data generation unit to generate communication data at a timing being based on the operation delay information included in the received command message;

a command transmission unit to transmit the received command message to a downstream side of the daisy chain configuration;

a communication data reception unit to receive communication data generated by another communication apparatus from the downstream side; and

a communication data transmission unit to sequentially transmit, to the upstream side, communication data generated by the communication data generation unit and the communication data received by the communication data reception unit;

each of the communication apparatuses further comprises a command data extraction unit to extract a command code and a parameter code contained in a first one of the command fields in the received command message sent by the communication control apparatus, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective one of the communication apparatuses, each of the parameter codes defining a respective parameter directly relating to the respective command code;

each of the communication apparatuses, upon processing the command identified by the respective extracted command code, deletes or changes to an invalid code said command code within the respective command field of the command message, prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

2. The communication system according to claim 1, wherein the operation delay information for each communication apparatus is designated according to the number of communication apparatuses in the daisy chain configuration.

3. A communication system in which a plurality of communication apparatuses and a communication control apparatus provided in a daisy chain configuration, and each communication apparatus relays data from one side of the communication system to another side, wherein

the communication control apparatus comprises:

a transmission unit to transmit, to the plurality of communication apparatuses, a command message comprising a plurality of command fields, each of the command fields having a command code and a parameter code, each of said command codes including respective operation delay information for each communication apparatus; and

a reception unit to receive communication data transmitted by the plurality of communication apparatuses, and

each communication apparatus comprises;

a determination unit to determine whether the respective communication apparatus is positioned at an end of the daisy chain configuration;

a command reception unit to receive the command message from an upstream side of the daisy chain configuration;

a communication data generation unit to generate communication data at a timing being based on the operation delay information included in the received command message;

a command transmission unit to transmit the received command message to a downstream side of daisy chain configuration;

a communication data reception unit to receive communication data generated by another communication apparatus from the downstream side; and

a communication data transmission unit to transmit, to the upstream side, communication data generated by the communication data generation unit, if the communication apparatus is determined to be the communication apparatus positioned at the end of the daisy chain configuration by the determination unit, and

wherein the communication data transmission unit sequentially transmits, to the upstream side, the communication data received by the communication data reception unit and then transmits, to the upstream side, the communication data generated by the communication data generation unit, if the communication apparatus is not determined to be the communication apparatus positioned at the end of the daisy chain configuration by the determination unit,

each of the communication apparatuses further comprises a command data extraction unit to extract a command code and a parameter code contained in a first one of the command fields in the received command message sent by the communication control apparatus, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective one of the communication apparatuses, each of the parameter codes defining a respective parameter directly relating to the respective command code;

each of the communication apparatuses, upon processing the command identified by the respective extracted command code, deletes or changes to an invalid code said command code within the respective command field of the command message, prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

4. A communication apparatus provided in a daisy chain configuration with other communication apparatuses, the communication apparatus relaying data from one side of the daisy chain configuration to another side, comprising:

a command reception unit to receive a command message including operation delay information from an upstream side of the daisy chain configuration;

a communication data generation unit to generate communication data at a timing being based on the operation delay information included in the received command message;

a command transmission unit to transmit the received command message to a downstream side of the daisy chain configuration;

a communication data reception unit to receive communication data generated by another communication apparatus from the downstream side;

a communication data transmission unit to sequentially transmit, to the upstream side, communication data generated by the communication data generation unit and the communication data received by the communication data reception unit;

a command data extraction unit to extract a command code and a parameter code contained in a first one of command fields in the received command message sent by a communication control apparatus, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective communication apparatus, each of the parameter codes defining a respective parameter directly relating to the respective command code;

the communication apparatus, upon processing the command identified by the respective extracted command code, deletes or changes to an invalid code said command code within the respective command field of the command message, prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

5. A communication apparatus provided in a daisy chain configuration with other communication apparatuses, the communication apparatus relaying data from one side of the daisy chain configuration to another side, comprising:

a determination unit to determine whether the communication apparatus is positioned at an end of the daisy chain configuration;

a command reception unit to receive a command message including operation delay information from an upstream side of the daisy chain configuration;

a communication data generation unit to generate communication data at a timing being based on the operation delay information included in the received command message;

a command transmission unit to transmit the received command message to a downstream side of the daisy chain configuration;

a communication data reception unit to receive communication data generated by another communication apparatus from the downstream side; and

a communication data transmission unit to transmit, to the upstream side, communication data generated by the communication data generation unit, if the communication apparatus is determined to be the communication apparatus positioned at the end of the daisy chain configuration by the determination unit, and

wherein the communication data transmission unit sequentially, transmits to the upstream side, the communication data received by the communication data reception unit and then transmits, to the upstream side, the communication data generated by the communication data generation unit, if the communication apparatus is not determined to be the communication apparatus positioned at the end of the daisy chain configuration by the determination unit,

the communication apparatus further comprises a command data extraction unit to extract a command code and a parameter code contained in a first one of command fields in the received command message sent by a communication control apparatus, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective communication apparatus, each of the parameter codes defining a respective parameter directly relating to the respective command code;

the communication apparatus, upon processing the command identified by the respective extracted command code, deletes or changes to an invalid code said command code within the respective command field of the command message, prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

6. A communication method of a communication system in which a plurality of communication apparatuses and a communication control apparatus provided in a daisy chain configuration, and each communication apparatus relays data from one side of the communication system to another side, comprising:

a command reception step, in each communication apparatus, of receiving from an upstream side of the daisy chain configuration, a command message comprising a plurality of command fields, each of the command fields having a command code and a parameter code, each of said command codes including respective operation delay information;

a communication data generation step, in each communication apparatus, of generating communication data at a timing being based on the operation delay information included in the received command message;

a command transmission step, in each communication apparatus, of transmitting the received command message to a downstream side of the daisy chain configuration;

a communication data receiving step, in each communication apparatus, of receiving communication data generated by another communication apparatus from the downstream side;

a communication data transmitting step, in each communication apparatus, of sequentially transmitting, to the upstream side, communication data generated at the communication data generation step and the communication data received at the communication data reception step;

a command data extraction step, in each communication apparatus, of extracting a command code and a parameter code contained in a first one of the command fields in the received command message, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective one of the communication apparatuses, each of the parameter codes defining a respective parameter directly relating to the respective command code;

a command code change step, in each communication apparatus, of deleting or changing to an invalid code the command code within the respective command field of the command message, upon processing the command identified by the respective extracted command code and prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

8. A non-transitory computer-readable storage medium storing a computer program for causing a computer to execute the communication method claimed in claim 6.

7. A communication method of a communication system in which a plurality of communication apparatuses and a communication control apparatus provided in a daisy chain configuration, and each communication apparatus relays data from one side of the communication system to another side, comprising:

a determining step, in each communication apparatus, of determining whether the communication apparatus is positioned at an end of the daisy chain configuration;

a command reception step, in each communication apparatus, of receiving from an upstream side of the daisy chain configuration, a command message comprising a plurality of command fields, each of the command fields having a command code and a parameter code, each of said command codes including respective operation delay information;

a communication data generation step, in each communication apparatus, of generating communication data at a timing being based on the operation delay information included in the received command message;

a command transmission step, in each communication apparatus, of transmitting the received command message to a downstream side of the daisy chain configuration;

a communication data reception step, in each communication apparatus, of receiving communication data generated by another communication apparatus from the downstream side;

a communication data transmitting step, in each communication apparatus, of transmitting, to the upstream side, communication data generated at the communication data generation step, if the communication apparatus is determined to be the communication apparatus positioned at the end of the daisy chain configuration at the determination step, and of sequentially transmitting, to the upstream side, the communication data received at the communication data reception step and then transmitting, to the upstream side, the communication data generated at the communication data generation step, if the communication apparatus is not determined to be the communication apparatus positioned at the end of the daisy chain configuration at the determination step;

a command data extraction step, in each communication apparatus, of extracting a command code and a parameter code contained in a first one of the command fields in the received command message, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective one of the communication apparatuses, each of the parameter codes defining a respective parameter directly relating to the respective command code;

a command code change step, in each communication apparatus, of deleting or changing to an invalid code the command code within the respective command field of the command message, upon processing the command identified by the respective extracted command code and prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.

9. A non-transitory computer-readable storage medium storing a computer program for causing a computer to execute the communication method claimed in claim 7.