Abstract: Disclosed is a fieldbus communication system, comprising: a field device to transmit data; a receiving device to receive the transmitted data; and a data management apparatus which is connectable to a communication system in which the field device and the receiving device are connected to a fieldbus, wherein the receiving device comprises a processing section to perform a transmission request regarding the transmitted data to the data management apparatus, and wherein the data management apparatus comprises: a transmitting/receiving section which is connectable to the fieldbus; a storage section to store the data transmitted from the field device; and a control section to read the stored data corresponding to the transmission request, from the storage section so as to transmit the read data to the receiving device, when the transmission request is received from the receiving device.

Abstract: Disclosed is an instrumentation control system, including: a first field device; and a second field device coupled to the first field device via a fieldbus. The first field device includes: a transmitting buffer to store data to be transmitted; a transmitter; and an inquiry processing section to cause the transmitter to retransmit the data stored in the transmitting buffer to the second field device in response to a request from the second field device. The second field device includes: a receiving buffer to store the data transmitted from the first field device; a checking section to determine whether the data stored in the receiving buffer is normal or not, and to make a data retransmission request to the first field device if the data stored in the receiving buffer is not normal; and a processing unit to perform predetermined processing based on the data which is determined to be normal.

Abstract: A network system wherein it is possible to reduce the amount of load on the mobile node and the amount of traffic from the mobile node to the IPv4/IPv6 translator and it is possible for the IPv4/IPv6 translator to know the node's current position within the IPv6 network in which the mobile node is moving. The network system having an IPv4/IPv6 translator for bilaterally translating packets between IPv6 and IPv4 protocols, where the translator is equipped with an address table for storing home addresses and care-of addresses in pairs for each MIPv6 mobile node and the translator is made to behave as a correspondent node of the MIPv6 mobile node in question after the mobile node has moved out of the home link thereof.

Abstract: There is provided an IP network system. The IP network system includes: a plurality of relays making up a ring network; a source host for transmitting a packet and connected to the ring network; and a destination host which conducts a packet communication with the source host through the ring network. Each of the relays is operable to transfer received packets containing a transfer direction information to the destination host through a right-handed route of the ring network and through a left-handed route of the ring network, based on the transfer direction information.

Abstract: In a field control system in which a plurality of field equipments that are operated in a previously set schedule and constitute a control loop perform a packet communication via a network, there is provided a configurator for collecting measured result packets to which a time stamp of each field equipment is affixed respectively, grasping at least any one of communication times between respective field equipments based on the time stamp, and adjusting operation schedules of respective field equipments in response to the communication times.

Abstract: A multiple logical node apparatus includes: an OS operated in the multiple logical node apparatus; an application operated under the OS; a physical network device for performing communication with a network medium, which is mounted on the multiple logical node apparatus; a virtual network device implemented by software; a first device driver for controlling the physical network device, being incorporated in the OS; and a second device driver for controlling the virtual network device, being incorporated in the OS.

Abstract: A network system using an IPv4/IPv6 translator for bilaterally translating packets between IPv6 and IPv4 protocols, wherein the IPv4/IPv6 translator is equipped with an address table for storing home addresses and care-of addresses in pairs for each MIPv6 mobile node. The IPv4/IPv6 translator functions as the correspondent node of the MIPv6 mobile node in question after the MIPv6 mobile node has moved out of the home link thereof.