Abstract: A time synchronization system includes time masters and a management master. The management master includes a management master priority requester that transmits to each time master a priority request frame and a management master highest priority processor that transmits, to a time master holding a priority that is the highest among priorities of the time masters, a highest priority notification frame for changing the priority to the highest priority. Each of the time masters includes a time master priority responder that transmits to the management master a priority response frame after receiving the priority request frame from the management master (and a time master highest priority processor that changes the priority thereof to the highest priority when the highest priority notification frame is received from the management master. The grandmaster transmits, to each time master, a time notification frame for synchronization of a time of the time master.

Abstract: A communication system includes master and slave devices connectable to each other and forming a ring communication path. The master device outputs management data to manage communication along the ring communication path in a CW and CCW directions and receives the management data in the CW direction and in the CCW direction, and outputs, in the CW direction and in the CCW direction, control data to be used by the slave device to control equipment. The slave device acquires a history of transmission of the management data output from the master device and received by the slave device in the CW direction and in the CCW direction, and processes, based on the acquired history, one of the control data output from the master device in the CW direction and the control data output from the master device in the CCW direction to control the equipment.

Abstract: A communication system includes master and slave devices connectable to each other and forming a ring communication path. The master device outputs management data to manage communication along the ring communication path in a CW and CCW directions and receives the management data in the CW direction and in the CCW direction, and outputs, in the CW direction and in the CCW direction, control data to be used by the slave device to control equipment. The slave device acquires a history of transmission of the management data output from the master device and received by the slave device in the CW direction and in the CCW direction, and processes, based on the acquired history, one of the control data output from the master device in the CW direction and the control data output from the master device in the CCW direction to control the equipment.

Abstract: A time synchronization system includes time masters and a management master. The management master includes a management master priority requester that transmits to each time master a priority request frame and a management master highest priority processor that transmits, to a time master holding a priority that is the highest among priorities of the time masters, a highest priority notification frame for changing the priority to the highest priority. Each of the time masters includes a time master priority responder that transmits to the management master a priority response frame after receiving the priority request frame from the management master (and a time master highest priority processor that changes the priority thereof to the highest priority when the highest priority notification frame is received from the management master. The grandmaster transmits, to each time master, a time notification frame for synchronization of a time of the time master.

Abstract: A network system constituted by a communication device performing communication of a first communication protocol for periodically transmitting data requiring low-delay transmission, a communication device performing communication of a second communication protocol for non-periodically transmitting data requiring low-delay transmission, and a communication device performing communication of a third communication protocol for transmitting data that does not require low-delay transmission, wherein a period in which transmission with the first protocol is permitted, a period in which transmission with the second protocol is permitted, and a period in which transmission with the third protocol is permitted are allocated, and each communication device transmits data in a period in which transmission with the protocol supported by the communication device is permitted, and transfers data received from another communication device in a period in which transmission with a protocol supported by a data transmission sou

Abstract: A network system constituted by a communication device performing communication of a first communication protocol for periodically transmitting data requiring low-delay transmission, a communication device performing communication of a second communication protocol for non-periodically transmitting data requiring low-delay transmission, and a communication device performing communication of a third communication protocol for transmitting data that does not require low-delay transmission, wherein a period in which transmission with the first protocol is permitted, a period in which transmission with the second protocol is permitted, and a period in which transmission with the third protocol is permitted are allocated, and each communication device transmits data in a period in which transmission with the protocol supported by the communication device is permitted, and transfers data received from another communication device in a period in which transmission with a protocol supported by a data transmission sou