Communications system having an authentication function

A communications system having an authentication comprising:

• a plurality of communications terminals communicating individually with external communications apparatuses, the communications terminals being provided individually with local authentication sections for checking whether the external communications apparatuses are authentic or not;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a switching portion for selectively connecting one of the communications terminals to the central control apparatus and a central authentication circuit for checking whether the individual communications terminals are authentic or not,
• wherein local authentication processes performed by the local authentication sections provided in the individual communications terminals to check whether the external communications apparatuses are authentic or not are performed independently of central authentication processes performed by the central authentication circuit provided in the relaying apparatus to check whether the individual communications terminals are authentic or not,
• wherein the central authentication circuit provided in the relaying apparatus checks whether a communications terminal is authentic or not by detecting an authentication signal that is added, for use in a central authentication process, to a signal transmitted from the communications terminal, and
• wherein the relaying apparatus performs a predetermined calculation operation on this authentication signal to produce and feed to the communications terminal a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not, and
• wherein the external communications apparatuses communicate with the central control apparatus through the communications terminals selected by the relaying apparatus and the relaying apparatus itself.

A communications system having an authentication comprising:

• a plurality of communications terminals communicating individually with external communications apparatuses, the communications terminals being Provided individually with local authentication sections for checking whether the external communications apparatuses are authentic or not;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a switching portion for selectively connecting one of the communications terminals to the central control apparatus and a central authentication circuit for checking whether the individual communications terminals are authentic or not,
• wherein, when an external communications apparatus has been found to be authentic by the local authentication section provided in a communications terminal, a signal indicating that the external communications apparatus is authentic is transmitted from the communications terminal to the relaying apparatus,
• wherein, on a basis of this signal transmitted from the communications terminal, the central authentication circuit provided in the relaying apparatus checks whether the communications terminal is authentic or not,
• wherein, in the relaying apparatus, the central authentication circuit checks whether the communications terminal is authentic or not by detecting the signal indicating that the external communications apparatus is authentic, and performs a predetermined calculation operation on this detected signal to produce a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not,
• wherein, when the central authentication circuit has found the communications terminal to be authentic, the switching portion connects the communications terminal to the central control apparatus to permit them to communicate with each other, and
• wherein the external communications apparatuses communicate with the central control apparatus through the communications terminals selected by the relaying apparatus and the relaying apparatus itself.

A communications system having a authentication function, comprising:

• a plurality of communications terminals for communication individually with external communications apparatuses;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a level shifter for converting a voltage level of signals transmitted from the central control apparatus to a voltage level that can be received by communications terminals and for converting a voltage level of signals transmitted from the communications terminals to a voltage level that can be received by the central control apparatus, a central authentication circuit for checking whether the individual communications terminals are authentic or not, and a switching portion for connecting or disconnecting data transfer lines between the central control apparatus and the communications terminals on a basis of outputs from the authentic circuit,
• wherein
• first the central authentication circuit of the relaying apparatus checks whether the communications terminals are authentic or not to prohibit whichever of the communications terminals is found unauthentic from being connected to the central control apparatus for communication therewith,
• then the relaying apparatus selects, as communications terminals to be connected to the central control apparatus, those of the communications terminals which have been found authentic by the central authentication circuit, and
• then the external communications apparatuses communicate with the central control apparatus through communications terminals selected by the relaying apparatus and the relaying apparatus itself.

A communications system having an authentication function, comprising:

• a plurality of communications terminals communicating individually with external communications apparatuses, the communications terminals being provided individually with local authentication sections for checking whether the external communications apparatuses are authentic or not;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a level shifter for converting a voltage level of signals transmitted from the central control apparatus to a voltage level that can be received by communications terminals and for converting a voltage level of signals transmitted from the communications terminals to a voltage level that can be received by the central control apparatus, a central authentication circuit for checking whether the individual communications terminals are authentic or not, and a switching portion for connecting or disconnecting data transfer lines between the central control apparatus and the communications terminals on a basis of outputs from the authentic circuit,
• wherein local authentication processes performed by the local authentication sections provided in the individual communications terminals to check whether the external communications apparatuses are authentic or not are performed independently of central authentication processes performed by the central authentication circuit provided in the relaying apparatus to check whether the individual communications terminals are authentic or not,
• wherein the central authentication circuit provided in the relaying apparatus checks whether a communications terminal is authentic or not by detecting an authentication signal that is added, for use in a central authentication process, to a signal transmitted from the communications terminal,
• wherein the relaying apparatus performs a predetermined calculation operation on this authentication signal to produce and feed to the communications terminal a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not, and
• wherein the external communications apparatuses communicate with the central control apparatus through the communications terminals selected by the relaying apparatus and the relaying apparatus itself.

A communications system having an authentication function, comprising:

• a plurality of communications terminals communicating individually with external communications apparatuses, the communications terminals being provided individually with local authentication sections for checking whether the external communications apparatuses are authentic or not;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a level shifter for converting a voltage level of signals transmitted from the central control apparatus to a voltage level that can be received by communications terminals and for converting a voltage level of signals transmitted from the communications terminals to a voltage level that can be received by the central control apparatus, a central authentication circuit for checking whether the individual communications terminals are authentic or not, and a switching portion for connecting or disconnecting data transfer lines between the central control apparatus and the communications terminals on a basis of outputs from the authentic circuit,
• wherein, when the external communications apparatus has been found to be authentic by the local authentication section provided in a communications terminal, a signal indicating that the external communications apparatus is authentic is transmitted from the communications terminal to the relaying apparatus,
• wherein, on a basis of this signal transmitted from the communications terminal, the central authentication circuit provided in the relaying apparatus checks whether the communications terminal is authentic or not, and
• wherein, in the relaying apparatus, the central authentication circuit checks whether the communications terminal is authentic or not by detecting the signal indicating that the external communications apparatus is authentic, and performs a predetermined calculation operation on this detected signal to produce a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not,
• wherein, when the central authentication circuit has found the communications terminal to be authentic, the switching portion connects the communications terminal to the central control apparatus to permit them to communicate with each other, and
• wherein the external communications apparatuses communicate with the central control apparatus through the communications terminals selected by the relaying apparatus and the relaying apparatus itself.

A communications system having an authentication function, comprising:

• a plurality of communications terminals for communicating individually with external communications apparatuses;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a switching portion for selectively connecting one of the communications terminals to the central control apparatus and a central authentication circuit for checking whether the individual communications terminals are authentic or not,
• wherein the central authentication circuit provided in the relaying apparatus checks whether a communications terminal is authentic or not by detecting an authentication signal that is added, for use in a central authentication process, to a signal transmitted from the communications terminal, and
• wherein the relaying apparatus performs a predetermined calculation operation on this authentication signal to produce and feed to the communications terminal a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not.

A communications system having an authentication function, comprising:

• a plurality of communications terminals for communicating individually with external communications apparatuses;
• a central control apparatus for controlling the communications terminals and for exchanging data related to the communications terminals and the external communications apparatuses with the communications terminals;
• and
• a relaying apparatus composed of a level shifter for converting a voltage level of signals transmitted from the central control apparatus to a voltage level that can be received by communications terminals and for converting a voltage level of signals transmitted from the communications terminals to a voltage level that can be received by the central control apparatus, a central authentication circuit for checking whether the individual communications terminals are authentic or not, and a switching portion for connecting or disconnecting data transfer lines between the central control apparatus and the communications terminals on a basis of outputs from the authentication circuit,
• wherein the central authentication circuit provided in the relaying apparatus checks whether a communications terminal is authentic or not by detecting an authentication signal that is added, for the use in a central authentication process, to a signal transmitted from the communications terminal, and
• wherein the relaying apparatus performs a predetermined calculation operation on this authentication signal to produce and feed to the communications terminal a signal on a basis of which the communications terminal checks whether the relaying apparatus is authentic or not.