Abstract: A design assistance device includes: a design information storage section configured to store design information containing at least information of slave devices and information of a topology in a network system in accordance with a design created by a user; an actual configuration information generation section configured to generate actual configuration information containing at least the information of the slave devices and the information of the topology in the actual network system; a comparison section configured to compare the design information and the actual configuration information; and an output section configured to generate a comparison screen indicating the respective configurations of the designed network system and the actual network system along with their commonalities and differences and outputting the comparison screen to a display device.

Abstract: A slave device is realized that establishes a link with a master device or another slave device such that a large link delay hardly occurs. The slave device includes a PHY unit, a COM unit, and a MPU unit. The PHY unit starts an operation according to the specification of the AutoMDI/MDI-X function when the slave device is turned on or the PHY unit itself is reset. After a predetermined time period has elapsed, the MPU unit resets the COM unit, and the PHY unit is reset in response to the reset of the COM unit.

Abstract: Delay in establishing communication is suppressed in a network system including a master device and a slave device. Provided is a setting method for performing communication setting for at least one of a master device and a slave device serving as a target device, the method including a storage step of storing a value of a communication parameter in a state in which the target device has established communication, and a setting step of, in communication setting in a preparatory stage for the target device to start communication, setting the value of the communication parameter that was stored in the storage step.

Abstract: A network system includes a master device (200), a plurality of slave devices; and a hub device including a plurality of ports on a downstream side. The master device (200) includes: a storage unit (204) in which setting information is stored, information on a device and topological information being set in the setting information; a real configuration information generating unit (202) that generates real configuration information including information on the device constituting an actual network system and topological information on the device; and a determination unit (203) that determines whether a destination of each device is correct by comparing the real configuration information to the setting information. The determination unit (203) determines that the destination of the slave device is correct, even if a position of the connected port is incorrect with respect to the slave device connected to the hub device.

Abstract: A design assistance device includes: a design information storage section configured to store design information containing at least information of slave devices and information of a topology in a network system in accordance with a design created by a user; an actual configuration information generation section configured to generate actual configuration information containing at least the information of the slave devices and the information of the topology in the actual network system; a comparison section configured to compare the design information and the actual configuration information; and an output section configured to generate a comparison screen indicating the respective configurations of the designed network system and the actual network system along with their commonalities and differences and outputting the comparison screen to a display device.

Abstract: A technique is provided for detecting a connection abnormality of a slave device, in a network system including a master device and slave devices. The technique includes a connection abnormality detection method in a network system including a master device and a plurality of slave devices. In the network system, data is transmitted from the master device and then returned to the master device through respective slave devices. Each slave device has an upstream-side port and a downstream-side port. The connection abnormality detection method includes acquiring topology information of the network system, closing or opening the port of each slave device such that a serial topology is formed to include a target slave device located on the downmost stream side, transmitting inspection data after the control of the port, and detecting a connection abnormality of the device on the basis of a status of return of the inspection data.