Network system, communication method, and computer readable medium

A communication method employed in a network system formed of a plurality of communication stations,

• wherein the plurality of communication stations include a master station having one or more communication ports and a slave station having two or more communication ports, and
• wherein each communication station of the plurality of communication stations comprises a relay device which relays two or more communication ports of the communication station and which can be put to a relay-disconnected status,
• the communication method comprising:
• by the slave station, in an initial state, putting the relay device to the relay-disconnected status and transmitting an assignment request requesting address assignment for the slave station,
• by the master station, in response to an assignment request from an adjacent slave station, performing address assignment for the slave station, and transmitting an assignment request response containing the assigned address,
• by the slave station, upon reception of the assignment request response, storing the address contained in the assignment request response to a memory, and putting the relay device to a relay status, and
• by the slave station, if receiving the assignment request after address assignment for the slave station is completed, performing address assignment for a slave station being a sender of the assignment request instead of relaying the assignment request, and transmitting an assignment request response containing an assigned address.

A non-transitory computer readable medium storing a communication program employed in a network system formed of a plurality of communication stations,

• wherein the plurality of communication stations include a master station having one or more communication ports and a slave station having two or more communication ports, and
• wherein each communication station of the plurality of communication stations comprises a relay device which relays two or more communication ports of the communication station and which can be put to a relay-disconnected status,
• the communication program causing a computer to execute:
• a process by the slave station, in an initial state, of putting the relay device to the relay-disconnected status and transmitting an assignment request requesting address assignment for the slave station,
• a process by the master station, in response to an assignment request from an adjacent slave station, of performing address assignment for the slave station, and transmitting an assignment request response containing an assigned address,
• a process by the slave station, upon reception of the assignment request response, of storing the address contained in the assignment request response to a memory, and putting the relay device to a relay status, and
• a process by the slave station, if receiving the assignment request after address assignment for the slave station is completed, of performing address assignment for a slave station being a sender of the assignment request instead of relaying the assignment request, and transmitting an assignment request response containing an assigned address.