Abstract: A communication apparatus acquires current load information including at least one current load value each indicating magnitude of a type of load that is currently imposed on the communication apparatus. A monitoring terminal transmits, to the communication apparatus, a request signal for acquiring an operational state of the communication apparatus. The communication apparatus determines a usable transmission method that is to be used for receiving the request signal and transmitting information on the operational state of the communication apparatus, based on the acquired current load information, and notifies the monitoring terminal about the determined usable transmission method. The monitoring terminal transmits the request signal to the communication apparatus using the usable transmission method notified by the communication apparatus.

Abstract: A remote maintenance repeater is used in a remote monitoring system. A command receiving unit receives a command from the monitoring apparatus. A destination selecting unit selects a transfer destination device to which the command received is transferred. A command transmitting unit transmits the command to the transfer destination device selected, at a specific frequency specific to the transfer destination device. A result receiving unit receives a result of execution of the command from the transfer destination device at the specific frequency. A result transmitting unit transmits the result to the monitoring apparatus.

Abstract: Disclosed is a communication control device whose configuration is capable of being changed flexibly without being affected by a computer's internal bus specifications, etc. Externally to the computer, a plurality of communication adapters are connected to a serial bus. This serial bus is compliant with the USB or the IEEE 1394 standard. A program for implementing part of protocol layer functions is downloaded from the computer to each communication adapter. The computer, using an application, implements the function of an upper layer in the protocol layer stack, and the adapters each implement part of the protocol layer functions using the downloaded program, and together they support a communication protocol.

Abstract: A remote maintenance repeater is used in a remote monitoring system. A command receiving unit receives a command from the monitoring apparatus. A destination selecting unit selects a transfer destination device to which the command received is transferred. A command transmitting unit transmits the command to the transfer destination device selected, at a specific frequency specific to the transfer destination device. A result receiving unit receives a result of execution of the command from the transfer destination device at the specific frequency. A result transmitting unit transmits the result to the monitoring apparatus.

Abstract: A computer in a system includes a storage area request unit for notifying a storage device of the request size of a storage area in the storage device and the identification information of the apparatus; a storage device access unit for accessing an area assigned to the apparatus in the storage device using the identification information of the apparatus and specified by the identification information of the area; and a storage area assignment unit for notifying the apparatus of the identification information of an area to be assigned by the storage device to the apparatus according to the notification from the storage area request unit. With the above described configuration of the system in which a plurality of apparatuses share a storage device, a process can be easily inherited using the storage device when an optional apparatus in the system becomes inoperable.

Abstract: A LAN terminal equipment comprises a plurality of slots, each capable of accommodating a LAN control board, at least one ROM socket capable of holding a MAC ROM, and an input/output control unit. The input/output control unit determines a correspondence between the LAN control board and the MAC ROM, thereby ensuring the uniqueness of MAC address and also making a primary/spare dual configuration possible.

Abstract: A LAN terminal equipment comprises a plurality of slots, each capable of accommodating a LAN control board, at least one ROM socket capable of holding a MAC ROM, and an input/output control unit. The input/output control unit determines a correspondence between the LAN control board and the MAC ROM, thereby ensuring the uniqueness of MAC address and also making a primary/spare dual configuration possible.

Abstract: A system comprised of multiplexed communication control units and a communication control unit for such multiplexing, where the switching between the stand-by unit and the active unit at the time of an abnormality can be performed in a short time and the cause of a breakdown obstructing operation can be grasped from the condition of the transmission line and the switching made conditional on that condition, thereby enabling highly reliable communication. The communication control units are connected in a multidrop configuration and both of the active unit and the stand-by unit are kept activated (communicable in state). The stand-by communication control unit transmits a frame through the transmission line at a timing not obstructing the communications, so it is possible to detect an abnormality in the active unit and rapidly switch to the stand-by unit at the time of an abnormality using the unit switching processing unit.