Yokogawa Electric Corporation

Masahito Endo

Hiroshi Miyata

Kensuke Hosoya

Yukiyo Akisada

Hiroki Endo

Shin-ichi Fujisawa

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.

Field control system and field control method

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.

IP network system

The invention is to solve the problem in that mutual communication between an IPv6-capble device and an IPv4-capble device has not been carried out in a system wherein the IPv6-capble device and the IPv4-capble device are mixed. An entry of a live list is retrieved when SM Device Annunciation is received from the IPv6-capble device, and a transmission IPv4 address is acquired from an IPv4 address pool if the entry is not found, thereby preparing translation rules so as to be stored in a translation rules storage section, while preparing an entry to be registered in the live list, whereby an IP address in a message is translated with reference to the translation rules. Further, a timestamp of the entry is updated every time when the SM Device Annunciation is received. Even if the address is contained in the message, the mutual communication between the IPv6-capble device and the IPv4-capble device can be carried out, and devices connected to the system can be controlled.

Gateway unit

A client to utilize a translator without changing the DNS server specification, when a service targeted at general clients is provided. An IPv6/IPv4 translator which reciprocally translates packets between IPv6 and IPv4 protocols and is configured so that a DNS query from a client reaches a translator DNS proxy using a dedicated domain effective as a specific DNS domain, the translator DNS proxy specifying an operation by entering a defined character string in FQDN.

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Musashino, Japan

Masahito Endo