| 主权项 |
1. A network unit, in a control system including a plurality of programmable logic controllers and a plurality of control networks respectively allocated with a network number, that can create diagnosis information
used in a connection between the programmable logic controllers and the control networks, allocated with a station number, and indicating a state of a control network connected with the network unit, the network unit comprising: a diagnosis-information transmission request unit that transmits a diagnosis-information transmission request while assuming a destination station number to be a value other than the station number and designating a destination network number; a routing control unit that stores routing information indicating correspondence between a destination control network and identification information on a network unit that is a relay station for the destination control network, and relay-controls the diagnosis-information transmission request received from the diagnosis-information transmission request unit in the network unit,
another network unit connected to same programmable logic controller as the network unit, ora control network connected to the network unit, in accordance with the routing information; and a diagnosis-information creation unit that creates the diagnosis information when having received the diagnosis-information transmission request having a network number of the control network connected to the network unit as the destination network number, and transmits the created diagnosis information to a sender of the diagnosis-information transmission request. |
