Communication system, communication device and communication method

A communication system of a plurality of devices connected to a predetermined bus, said system comprising:

• a first device adapted to transmit data as a periodical packet to the bus;
• a second device having a status monitoring means for monitoring that status of said first device and a packet receiving means for receiving the periodical packet from said first device;
• and
• upon detecting the status of said first device read for transmitting a periodical packet, said second device starts receiving said packets by said receiving means.

A communication device to be connected to some other communication device by way of a predetermined bus, said communication device comprising:

• a packet transmission monitoring means for monitoring any transmission of a periodical packet from said other communication device by way of a bus;
• a packet receiving means for receiving a periodical packet from said other communication device;
• and
• a control means for causing said packet receiving means to receive the periodical packet from said other communication device upon detecting the packet as an available packet by said packet transmission monitoring means.

A communication device to be connected to some other communication device by way of a predetermined bus, said communication device comprising:

• a status monitoring means for monitoring the status of said other communication device;
• a packet receiving means for receiving a packet from said other communication device;
• and
• a control means for causing said packet receiving means to receive a packet by said packet receiving means upon detecting the status of said other communication device of being ready for transmitting a periodical packet.

A communication method for data communication to be conducted among devices connected to each other by way of a predetermined bus, said method comprising:

• a packet transmittimg step of transmitting data to the data transmission bus as a periodical packet;
• a monitoring step of monitoring the periodical packet being transmitted in said first step;
• and
• a packet receiving of starting to receive the packet upon detecting the transmission of the packet as a packet available to it.

A communication method for data communication to be conducted among devices connected to each other by way of a predetermined bus, said method comprising:

• a packet transmitting step of transmitting data to a data transmission bus as a periodical packet;
• a status detecting step of monitoring the status of said packet transmitting step and detecting the status ready for transmitting a periodical packet in said packet transmitting step;
• and
• a packet receiving step of starting to receive the packet upon detecting the status of said first step of being ready for transmitting a periodical packet.

A communication system of a plurality of communication devices connected to a predetermined bus, said communication system comprising:

• a first communication device adapted to transmit data as a periodical packet to said bus;
• a second communication device having a packet receiving means for receiving the periodical packet transmitted from said first device;
• said first transmission device having:
• a receiving means for receiving the notification request transmitted from said second device and requesting a notification of the status of said first communication device of being ready to start transmitting packets;
• a notification command transmitting means for transmitting a notification command for notifying the status of being ready to start transmitting packets upon receiving said notification request command and coming into a status of being ready to start transmitting a packet;
• and
• a data transmitting means for transmitting data to said second communication device as a packet;
• said second transmission device having:
• a notification request command transmitting means for generating a notification request command for requesting a notification of the status of said first communication device of being ready to start transmitting a packet and transmitting it to said first communication device;
• a notification command receiving means for receiving a notification command transmitted from said first communication means to notify the status of said first communication device of being ready to start transmitting a packet in response to said notification request command;
• and
• a packet receiving means adapted to start receiving a packet from said first device according to the received notification command.

A communication device to be connected to some other communication device adapted to transmit a packet by way of a predetermined bus, said communication device comprising:

• a notification request command transmitting means for generating a notification request command for requesting a notification from said other communication device of the status thereof of being ready to start transmitting a packet and transmitting it to said other communication device;
• a notification command receiving means for receiving the notification command transmitted from said other communication device for notifying the status of said other communication device of being ready to start transmitting a packet in response to said notification request command;
• and
• a packet receiving means adapted to start receiving a packet from said other communication device according to said received notification command.

A communication device for transmitting data to some other communication device, said communication device comprising:

• a receiving means for receiving the notification request command transmitted from said other communication device for requesting a notification of the status of said communication device of being ready to start transmitting a packet;
• a notification command transmitting means for transmitting a notification command for notifying the status thereof of being ready to start transmitting a packet upon receiving said notification request command and becoming ready to start transmitting a packet;
• and
• a data transmitting means for transmitting data to said other communication device as a packet.

A communication method for communicating with some other communication device adapted to transmit a packet by way of a predetermined bus, said communication method comprising:

• a notification command transmitting step of generating a notification request command for requesting a notification of the status of said other communication device of being ready to start transmitting a packet and transmitting said request to said other communication device;
• a notification command receiving step of receiving the notification command transmitted from said other communication device for notifying the status thereof of being ready to start transmitting a packet in response to said notification request command;
• and
• a packet receiving step of starting to receive a packet from said other communication device according to said received notification command.

A communication method for transmitting data from a communication device to some other communication device as packet, said communication method comprising:

• a receiving step of receiving the notification request command transmitted from said other communication device for requesting a notification of the status of said communication device of being ready to start transmitting a packet;
• a notification command transmitting step of receiving said notification request command and transmitting a notification command for notifying the status of said communication device of being ready to start transmitting a packet upon becoming ready to start transmitting a packet;
• and
• a data transmitting step of transmitting data to said other communication device as a packet.