JP2000316008A - Atm bus system to which power is feedable and branching device used for the atm bus system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ATM bus system where it is not required to register a terminal available on the occurrence of a power failure to a system in advance and to connect the terminal to a specific port. SOLUTION: The ATM bus system is a system where a plurality of branching devices 30 are connected to incoming and outgoing buses connected to a master unit 10. Each branching device 30 is provided with a plurality of terminal ports, a feeding necessity discrimination means that discriminates whether or not a terminal 50 connected to the terminal port receives power required for its operation from the branching device and a feeding control means that controls feeding to each terminal port. Then power is temporarily supplied to each terminal port at start via the feeding control means, whether or not the terminal connected to the terminal port receives the power required for its operation from the branching device is discriminated and the feeding control means supplies power only to the terminal ports being feeding objects.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM bus system in which a plurality of branching devices communicate using ATM (asynchronous transfer mode) cells which are connected in a subordinate manner or connected in a branch (tree shape) to a common bus. The present invention relates to a method for efficiently supplying power for driving a terminal from a branching device accommodated in the ATM bus system.

[0002]

2. Description of the Related Art In a conventional ATM communication system, power supply (power supply) for operating a terminal is not considered from the system itself as in a key telephone system, and each terminal is independently provided with a commercial power supply. Powered by In such a system, when the commercial power supply to the terminal is cut off (power failure), it is necessary for the terminal to independently provide a backup power supply. Also, like the key phone system, the number of connected terminals is limited,
In particular, terminals that can be used even during a power failure provided a port configured to supply power and connect a communication line to the branch device at the time of a power failure, and connected to this specific port to supply power from the branch device. .

However, in the conventional system, the terminals available at the time of a power failure must be registered in the system in advance, or the terminals available at the time of a power failure must be connected to a specific port. Was not available if the connection was made incorrectly,

Further, in the ATM bus system, since branching devices are connected in cascade, when a terminal that can be used at the time of a power failure is arranged in a branching device connected to a location near the end of the bus, a branching device in the middle is Must be set to the operating state to transmit a communication signal, it is necessary to provide power for operating the intermediate device located in the middle, and a large-capacity backup power source must be prepared.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in an ATM bus system capable of supplying power at the time of a power outage. It is an object of the present invention to provide an ATM bus system in which there is no need to connect a specific terminal to a specific port, and the location of the terminal is not limited.

Further, the present invention provides an ATM bus system in the above-described ATM bus system, which reduces the power consumption and the power consumption of a branching device that relays ATM cells when power is supplied to a branching device near the end of the bus at the time of a power failure. The purpose is to:

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device. And power supply necessity determining means for determining whether or not the terminal connected to the terminal port operates by receiving power from the branching device necessary for operation and controlling power supply to each terminal port. Power supply control means for temporarily supplying power to each terminal port via the power supply control means at the time of startup, and receiving power from the branching device side necessary for the operation of the terminal connected to the terminal port. It is determined whether or not the terminal operates in accordance with the power, and only the terminal port to be supplied with power is supplied with power via the power supply control means.

According to a second aspect of the present invention, in an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, the branching device is connected to a plurality of terminal ports and a terminal port. Power supply necessity determining means for determining whether or not the terminal operates by receiving power from the branch device side necessary for operation of the terminal; an upstream power supply line and a communication line; and a downstream power supply line and a communication line. A bypass circuit for directly connecting a line is provided, and it is determined whether or not the terminal required to operate the terminal operates by receiving power from the branching device side, and all terminal ports of the branching device are connected from the branching device side. When it is determined that power supply is unnecessary, the power supply line and the communication line on the upstream side and the power supply line and the communication line on the downstream side are connected by the bypass circuit at the time of a power failure.

According to a third aspect of the present invention, in an ATM bus system in which a plurality of branch devices are connected to an upstream bus and a downstream bus connected to a main device, a power receiving interface for receiving power, a power receiving interface, A power transmission interface for transmitting to the downstream side and a power supply interface for supplying power to itself and a terminal accommodated therein are provided, and the power received from the power reception interface is distributed to the branch device itself, the power transmission interface, and the power supply interface. did.

Further, according to a fourth aspect of the present invention, in the ATM bus system according to any one of the first to third aspects, one of the buses used as a downstream bus of the ATM bus is downstream of the farthest end branching device. The ATM-M bus system was connected to the other bus used as an up bus by turning back on the side.

According to a fifth aspect of the present invention, there is provided an ATM bus system according to any one of the first to third aspects, wherein one of the upstream bus and the downstream bus of the ATM bus starts from the main unit and starts from the main unit. AT which returns to the main unit after returning from the main unit to the bus for transmitting ATM cells
An M cell receiving bus was used.

According to a sixth aspect of the present invention, in the ATM bus system according to any one of the first to third aspects, the branch device is connected to the main device in a tree-like (branch-like) manner by an upstream of the ATM bus. Connected to bus and down bus.

According to a seventh aspect of the present invention, in the ATM bus system according to any one of the first to sixth aspects, the branch device includes a terminal that operates during a power failure among terminal accommodation ports provided in the branch device. Power supply necessity determining means for determining which port is connected or which terminal is to be supplied with power is provided.

According to an eighth aspect of the present invention, in the ATM bus system according to the seventh aspect, in the ATM bus system or the ATM-M bus system, the power supply necessity determining means provided in the branching device includes: A function is provided to determine how much power required for the connected terminal to operate is received from the branching device, and power is supplied to each port (terminal) within the range of the power capacity previously allocated as the branching device. Was controlled.

According to a ninth aspect of the present invention, in the ATM bus system according to any one of the first to sixth aspects, when it is determined that a terminal operated at the time of a power failure is not connected to any of the terminal accommodation ports, The power receiving interface and the power transmission interface are connected by a bypass circuit, and the power is relayed to another branch device.

Further, according to a tenth aspect of the present invention, in a branching device used in an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, a power receiving interface for receiving power, Power transmission interface for transmitting the generated power to the downstream side, a power supply interface for supplying power to itself and the terminals accommodated therein, and which of the terminal accommodating ports provided in the branching device is connected to a terminal operated during a power outage Or, a power supply necessity determining means for determining which terminal is to be supplied with power is provided,
The power received from the power receiving interface is distributed to the branch device itself, the power transmission interface, and the power supply interface.

According to an eleventh aspect of the present invention, in a power supply control method in an ATM bus system in which a plurality of branch devices are connected to an upstream bus and a downstream bus connected to a main device, the branch device includes a plurality of terminal ports; Power supply necessity determining means for determining whether or not the terminal connected to the terminal port operates by receiving power required for operation from the branching device side, and power supply for controlling power supply to each terminal port A control means is provided, and a power failure operation command is sent from the main unit to each branch device to confirm whether power needs to be supplied from a power supply in the event of a power failure. It is characterized in that power is supplied temporarily through the control means, and a response as to whether or not power is to be received from the branch device in the event of a power failure is transmitted.

According to a twelfth aspect of the present invention, in the power supply control method in the ATM bus system according to the eleventh aspect, the power consumption of the branch device is included in a response from the branch device, and the main device operates within the range of the power supply capacity. A power supply control switch of a port that can be operated is operated.

According to a thirteenth aspect of the present invention, in the power supply control method for an ATM bus system according to the eleventh or twelfth aspect, one of the buses used as the down bus of the ATM bus is located downstream of the farthest branch device. It is characterized in that the ATM-M bus system is connected to the other bus which is turned back and used as an up bus.

According to a thirteenth aspect of the present invention, in the power supply control method in the ATM bus system according to the eleventh or twelfth aspect, one of the upstream bus and the downstream bus of the ATM bus starts from the main unit and returns to the main unit. It is characterized in that the bus is an ATM cell transmission bus, and the other bus is an ATM cell reception bus starting from the main unit and returning to the main unit.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an ATM bus system according to the present invention will be described below with reference to the drawings. This ATM
The bus system is configured as an ATM-M bus system, in which a power receiving unit and a power transmitting unit are provided in a branching device, and the power received by the branching device is distributed to its own device and other interfaces.

Referring to FIG. 1, an ATM-M according to the present invention will be described.
The configuration of the bus system will be described. The ATM-M bus system 1 includes a main device 10, a plurality of cascaded branch devices 30-1 to 30-3, and terminals 50-1A to 50- accommodated in the branch devices 30-1 to 30-3. 3B and branching device 3
0-2, a power supply that operates with a commercial power supply that supplies operating power to the branching device 30-2 itself, the subordinate branching device 30-3, and the terminals 50-2A to 50-2B accommodated in the branching device 30-2. An adapter 90 is provided.

The main unit 10 includes an M bus connection unit 11 for terminating a branch device of the M bus system, a power supply circuit 19 that can be backed up, and the like.

The main unit 10 and the first branching device 30-1 are connected by a signal line (M bus) 70-1.
The intermediate branching device 30-2 is connected by a signal line 70-2, and the intermediate branching device 30-2 and the terminal branching device 30-3 are connected by a signal line 70-3.

The signal line 70-1 connecting the main unit 10 and the branching device 30-1 and the branching device 30-1 and the branching device 30-
2 and the signal line 70-3 connecting the branching device-2 and the farthest branch device 30-3 are respectively composed of a downstream bus and an upstream bus, and the farthest end branch device 30-b. On the downstream side of 3, the downstream bus is turned back and connected to the upstream bus. The ATM cells sent out from the main unit 10 onto the down bus are turned back downstream of the farthest branching device 30-3 and sent up the up bus toward the main unit. The ATM cells sent from the main device 10 to the branching device are sent to the downstream branching device as empty cells after receiving the information at the branching device. Each branch device puts information on an empty cell on the downstream bus or upstream bus and transmits the information to the main device. Such an ATM bus system in which an ATM cell is turned back at the farthest branch device is referred to as A in this specification.
It is called a TM-M bus system.

Further, the main device 10 and the leading branch device 30
Reference numeral -1 denotes a power supply line 75-1, and the intermediate branch device 30-2 and the terminal branch device 30-3 are connected by a power supply line 75-3.

The branching device 30-1 and the terminals 50-1A and 50-1
-1B is the interface cable 77-1A, 77-1
B, the branching device 30-2 and the terminals 50-2A and 50-2B
Are interface cables 77-2A and 77-2B.
The branching device 30-3 and the terminals 50-3A and 50-3B are connected by interface cables 77-3A and 77-3B, respectively.

Terminals 50-1A, 50-1B, 50-2
B, 50-3A, and 50-3B are each supplied with power from a commercial power supply. The terminal 50-2A is supplied with power from the branching device 30-2.

In this embodiment, the backup power supply circuit 19 mounted on the main device 10 supplies power to the leading branch device 30-1 via the power supply line 75-1 via the M bus connection unit 11. Has been supplied.

In this embodiment, the leading branching device 30
-1 is supplied with power from the power supply circuit 19 of the main device 10 via the feed line 75-1, and the intermediate branching device 30-2
, Power is supplied from the power supply adapter 90 via the power supply line 75-2. Further, power is supplied to the terminal branch device 30-3 from the intermediate branch device 30-2 via the feed line 75-3.

Also, a power adapter 9 operating on commercial power supply
0 is the intermediate branching device 30- via the feed line 75-2.
2 is powered. The branching device 30-2 receives the power received from the power adapter 90, and
-2 itself, and drives the internal circuit of the terminal 50-2A housed in the branching device 30-2 via the power supply line 77-2PA of the interface cable 77-2A.
To the subsequent branching device 3 via the feed line 75-3.
It relays to 0-3.

Further, the succeeding branching device 30-3 drives the branching device 30-3 itself with the power received from the preceding branching device 30-2, and also feeds the power supply line 77-3PA of the interface cable 77-3A. To the terminal 50-3A accommodated in the branching device 30-3.

With this configuration, power can be supplied to the branching devices 30-1 and 30-3 that are not connected to the power supply, and the power can be supplied to the terminal 50-2A that is not connected to the commercial power supply. Can be supplied. Power supply to the terminal 50-3A connected to the commercial power supply is as follows.
It can be used as a backup power supply in the event of a commercial power failure.

Referring to FIG. 2, an ATM-M according to the present invention will be described.
A communication signal interface, a power transmission interface, and a power transmission interface between a power transmission interface of a main device and a power reception interface of a branch device, that is, a connection configuration between the main device 10 and the leading branch device 30-1 in FIG. A mode in which the power receiving interface is provided separately will be described.

The main unit 10 includes a transmitter 121 and a receiver 12
2, transmission pulse transformer 123, reception pulse transformer 1
It has an M bus connection unit 11 having a communication signal interface circuit 12 consisting of 24 and a power transmission interface 14 connected to a power supply circuit 19.

The branching device 30-1 comprises an upstream communication signal interface 32 comprising a transmitter 321, a receiver 322, a transmission pulse transformer 323 and a reception pulse transformer 324.
And a power receiving circuit 37 serving as a power receiving interface.

Communication signal interface 12 of main unit 10
And upstream communication signal interface 3 of branching device 30-1
2 are connected by a signal line 70-1. The signal line 70-1 has a down line 701 and an up line 702. The power supply (power transmission) circuit 19 of the main device 10 and the power receiving circuit 37 of the branching device 30-1 are connected to a power supply line 75-1.
Connected by The feed line 75-1 is connected to the line 7
51, 752. As described above, in this embodiment, the communication signal interface 12 and the power transmission interface 14 and the communication signal interface 32 and the power reception interface (power reception circuit) 37 are configured to use independent (separated) lines.

The connection configuration between the branching device 30 and the terminal 50 accommodated in the branching device will be described with reference to FIG.
In this embodiment, the interface cable (signal line) 77
To transmit a communication signal and power, that is, a mode in which a communication signal interface, a power transmission interface, and a power reception interface are shared. Branching device 3
0 terminal side communication signal interface 34
1, a receiver 342, a transmission pulse transformer 343, and a reception pulse transformer 344. The branching device 30
In the example, the power from the power receiving circuit 37 is supplied to the middle point of the output side winding of the transmission pulse transformer 343 and the middle point of the input side winding of the receiving pulse transformer 344 via the power supply control switch circuit 38.

The terminal 50 comprises a transmitter 511 and a receiver 51
2, a communication signal interface 51 including a transmission pulse transformer 513 and a reception pulse transformer 514, and a power receiving circuit 58. The terminal 50 is configured to extract power from the midpoint of the output side winding of the transmission pulse transformer 513 and the midpoint of the input side winding of the reception pulse transformer 514 and supply the extracted power to the power receiving circuit 58.

Here, the power supply control switch circuit 38 on the branching device 30 side and the power receiving circuit 58 of the terminal 50 are not connected by an independent power supply line 75 as shown in FIG. The output via the power supply control switch circuit 38 is supplied to the midpoint between the output side winding of the transmission pulse transformer 343 and the input side winding of the reception pulse transformer 344, and is superimposed and transmitted on the interface cable 77. This power is received from the midpoint of the input side winding of the receiving pulse transformer 514 on the terminal 50 side and from the midpoint of the output side winding of the transmitting pulse transformer 513, and is input to the power receiving circuit 58 of the terminal 50.

The method of supplying power through a signal line (interface cable) using the communication signal interface as a power supply (power transmission / reception) interface in this manner is generally called a phantom power supply method. In the present invention, the transmission method of the communication signal and the transmission method of the power are, as shown in FIG.
As shown in FIG. 3, any of the methods of transmitting the communication signal and the electric power together on the signal line can be adopted.

FIG. 4 shows an ATM-M according to the present invention.
The configuration of the branching device 30 used in the bus system will be described.
The branching device 30 includes an upstream communication signal interface 32
A downstream communication signal interface 33, a terminal communication signal interface 34, an M bus control circuit 35, a terminal control circuit 36, a power receiving circuit 371 from the upstream side, a power receiving circuit 372 from the power adapter 90, Power supply control switch circuit 3 for transmitting the received power to the downstream side or the terminal side
And 8.

The power receiving circuit 372 is connected to the external power adapter 9.
It has a function of receiving the operating power by being connected to the terminal 0 and constitutes a power receiving interface. The circuit including the transmitter 321, the receiver 322, the transmission pulse transformer 323, the reception pulse transformer 324, and the power receiving circuit 371 is:
The power receiving interface shown in FIG. 3 that receives power transmitted from the preceding branch device or the M bus connection unit 11 by sharing the signal line 70 is realized, and the branch device 30 can be also supplied by a commercial power supply. Main unit 1 during power outage
This indicates that any of the backup power supplies supplied from 0 is operable.

In the branching device 30, the power obtained by the power receiving circuit 371 or 372 is used by the branching device 3.
In addition to driving the upstream communication signal interface 32, the downstream communication signal interface 33, and the terminal communication signal interface 34, the operating power is supplied to the M bus control circuit 35 and the terminal control circuit 36. Power receiving circuit 37
1 or the power received via the power receiving circuit 372 is also distributed to the terminal 50 accommodated in the branch device and the downstream branch device via the power supply control switch circuit 38 for realizing the power distribution function.

The power supply control switch circuit 38 includes, for example, a power supply control switch 381 for forming a path to the downstream communication signal interface 34 and a power supply control switch 382A for forming a path to the interface port of the terminal side communication signal interface 34A. And a power supply control switch 382B that forms a path to the interface port of the terminal-side communication signal interface 34B.

Each of the power supply control switches 381, 382A, and 382B of the power supply control switch circuit 38 outputs the result obtained by the power supply necessity determination means described later to the terminal control circuit 36.
In the ON state, power supply to each interface port is enabled, and in the OFF state, power supply to each interface port is prohibited (stopped).

Referring to FIG. 5, a method for specifying a terminal to be supplied with power will be described. In the branching device having the function of specifying the power supply target terminal, the structure of the communication signal interface and the power transmission interface / power receiving interface for power supply conforms to the interface shown in FIG. Of communication signal interfaces corresponding to the maximum number of communication signals are provided. Each communication signal terminal interface is provided with a power supply necessity determining means 31 as means for determining whether power supply is necessary according to the present invention.

The power supply necessity determining means 31 includes a detection circuit 311
, A resistor 312 having one end connected to the power supply, a detection signal line 313, and a detection signal line 314 having one end grounded. The power supply necessity determination unit 31 determines whether power supply is necessary based on the presence or absence of a current loop formed by the pair of detection signal lines (313 and 314). Terminal 50 and branching device 30
The detection signal line 313 and the detection signal line 314 are accommodated via the connector 71 in the signal line 77 connecting the.

Here, in this embodiment, the case where a current loop is formed on the detection signal line (L level is detected) is regarded as the need for power supply, and the case where no current loop is formed (H level is detected) is considered. It is defined that power supply is unnecessary (No).

A loopback of the detection signal line 313 and the detection signal line 314 is formed inside the terminal device 50A that requires power supply. A detection signal line 31 serving as a detecting means is provided between the terminal 50A requiring power supply and the branching device 30.
3A and the detection signal line 314A are connected to the terminal 50A via the signal line 70A, and the detection signal line 313A and the detection signal line 314A are connected inside the terminal 50A.

The branching device 30 for determining whether or not power supply to the terminal 50A is necessary is a current loop (L level signal logic) formed by the loopback of the signal lines 313A and 314A inside the terminal 50A. Is detected by the detection circuit 311A. Thereby, the branching device 30
Recognizes that the terminal 50A is a terminal requesting power supply, and recognizes the power supply control switch circuit 3 shown in FIG. 4 and FIG.
8 is turned on, and the terminal 5 is turned on.
Power supply to 0A is started.

The terminal 50B is shown as a terminal that operates by obtaining operating power from a storage battery 59B built in the terminal 50B itself during a power failure. The terminal 50B is different from the terminal 50A described above in that the detection signal lines 313B and 314B are connected to the connector 71 of the signal line 70B connected to the branching device 30.
Loopback inside B.

The branching device 30 turns on the power supply control switch 382B by detecting that the signal is at the L level signal logic by the detection circuit 311B in the same manner as the terminal 50A described above. It operates without using the power transmitted via the line 70B.

The terminal 50C that does not operate at the time of a power failure driven by only the commercial power supply (does not require power supply from the branching device 30) is connected to either the terminal 50C or the interface cable 77C connected to the branching device 30 or the connector 71C. In this case, the detection signal line 313C and the signal line 314C are not looped back.

The branching device 30 determines that the signal is the H level signal logic in the detection circuit 311C and that power supply to the terminal 50C is unnecessary, and the power supply control switch 38
2C is turned off, and power supply to terminal 50C is stopped.

In this way, it is possible to determine whether or not power supply to the terminals 50A, 50B, 50C accommodated in the branching device 30 is necessary.

Referring to FIGS. 6 and 7, a second example of a method for specifying a terminal to be supplied with power according to the present invention will be described. This method uses the branching device 30 and the terminal 50 transferred on the communication signal interface shown in FIGS.
The power failure operation command C shown in FIG.
100, power supply request response R154 at power failure, active response R155 at power failure, inactive response R15 at power failure
6 in the terminal control circuit 36 of the branching device 30,
This is a method of executing the power failure operation and the power supply necessity confirmation protocol of FIG.

The processing executed by the terminal control circuit 36 of the branching device 30 will be described with reference to the flowchart of FIG. The terminal control circuit 36 activates the terminal 50A by temporarily turning on the power supply control switch 382A for the terminal 50A (S1), and transmits a power failure operation confirmation command C100 for confirming the power failure operation and the necessity of power supply to the terminal 50A. (S
2). In the event of a power failure, the terminal 50A that wants to operate (activate) by supplying power from the branching device 30 receives the command C100
Power supply request response R154 as a response to
Will be returned. The branching device 30 receives the response R154 (S3), determines that power supply is necessary (S4),
With the power supply control switch 382A kept in the ON state, the process shifts to the confirmation of the next terminal port.

For the next terminal 50B, the power supply control switch 382B is temporarily turned on (S6), and the power failure operation confirmation command C for confirming the power failure operation and the necessity of power supply is provided.
100 is transmitted to the terminal 50B (S7). The terminal 50B that wants to operate in the event of a power failure but does not require power supply from the branching device 30 returns a power failure activation response R155 as a response to the command C100. The branching device 30 receives the response R155 (S8), determines that power supply is unnecessary (S9), turns off the power supply control switch 382B, stops power supply to the terminal 50-2B, and stops the next terminal port. Move on to confirmation.

The same processing (S11 to S15) is performed for the next terminal 50C.

In this embodiment, the terminal 50 and the terminal control circuit 36 in the branching device 30 are provided with a protocol processing function. The main device 10 and the branching device 30 are provided with a message code for controlling a dedicated power supply control switch.
It is also possible to determine the necessity of power supply between the two.

A third example of a method for specifying a terminal to be supplied with power will be described with reference to FIGS. 8 and 9. In this example, unlike the method shown in FIGS. 5 to 7 described above, the power supply control switch for each terminal is temporarily turned on to determine whether or not the terminal is operated by the power supply from the branch device. And an inspection is performed, and an energization necessity determination unit using an energization detection circuit that determines whether each terminal is actually consuming power is provided.

FIG. 8 shows a case where the terminal 50 is a terminal that requires power supply. The branching device 30 includes a power supply necessity determination unit 31, a terminal-side communication signal interface 34,
It has a terminal control circuit 36 and a power supply control switch 382. The power supply necessity determination unit 31 includes a power supply detection circuit 317 that detects a power consumption state of the terminal.

The terminal 50 has a communication signal interface 51
The terminal itself is operated by receiving the power taken out from the power receiving circuit 58.

The branching device 30 temporarily turns on the power supply control switch 382 connected to the interface port of the terminal for which power supply is required, and supplies power to the terminal 50 via the interface cable 77. In this state, the terminal 50 inputs the supplied power to the power receiving circuit 58 and actually consumes the power. The power supply detection circuit 317 of the power supply necessity determination means 31 in the branching device 30 detects that the terminal 50 is consuming power and notifies the terminal control circuit 36 of the power supply state. Therefore, the terminal control circuit 36 determines that the terminal 50 is a terminal that requires power supply, and continuously turns on the power supply control switch 382 that has been temporarily turned on first to continue power supply. The terminal 50 is driven.

The terminal 50 shown in FIG. 9 is an example of a device in which the terminal 50 is driven by a power supply circuit 57 operated only by a commercial power supply. Similarly to the example of FIG. 8, the power supply control switch 382 connected to the interface port of the terminal whose power supply is required is determined to be temporarily turned on for this terminal device 50 via the interface cable 77. Supply to terminal 50. At this time, the terminal 50 is driven by the power from its own power supply circuit 57 and
Does not consume the power supplied from the interface cable 77 via the interface cable 77.

The power supply detection circuit 317 of the power supply necessity determination means 31 in the branching device 30 detects that the terminal 50 is not consuming power and notifies the terminal control circuit 36 of the non-power supply state. Therefore, the terminal control circuit 36 determines that the terminal 50 does not require power supply, turns off the power supply control switch 382 that was temporarily turned on first, and stops power supply to the terminal device 50.

Next, a system in which the power consumption of each terminal is determined and power is supplied within the range of the allocated power amount will be described with reference to FIG. FIG.
The system shown in (A) increases the number of detection signal lines of the system shown in FIG. 5 and divides the content (whether a power failure operation or power supply is required) indicated by the signal and analyzes the request of the terminal. This is a system with a sophisticated detection circuit.

The power supply necessity determining means 31 of the branching device 30
Detection signal line 315, detection signal line 316, detection signal line 31
3 has a detection circuit 311 to which signals from three lines are input. The detection signal line 314 is grounded, and the signal line 3
13, 315 and 316 are connected to a power supply via separate resistors 312, respectively.

The terminal 50 sets the connection of the connector 52 according to the power failure and the power consumed by the terminal 50, and selectively loops back the detection signal line from the power supply necessity determining means 31.

Since the detection circuit 311 of the branching device can indicate the power consumption of the terminal 50 by a 3-bit logical level, in the example shown in FIG. 5, only the necessity of power supply is shown in binary. On the other hand, in FIG. 10, a criterion of the amount of power required at the time of power supply can be transmitted to the terminal control circuit 36 via the detection circuit 311 as eight values.

FIG. 10B shows an example of the signal logic value. In FIG. 10B, the levels of the respective detection signal lines 313, 315, and 316 input to the detection circuit 311 are shown in the signal logic value column in the state of whether or not to operate at the time of power failure and the operation state at the time of energization ( (Power consumption) is shown in the power failure / power on operation column.

For example, the branching device 30 having a plurality of terminal ports adds necessary power consumption using the signal detection level (logical value), and adds the required power consumption to each terminal port until a predetermined value is reached. By controlling so that the corresponding power supply control switch 382 is turned on, power can be effectively distributed.

Referring to FIG. 11 and FIG.
In addition, a description will be given of a method in which, in a process similar to that of FIG. 7, an information element serving as a measure of power required by a terminal is added to the message code from the terminal to the branching device shown in FIG.

FIG. 11 shows a command and response format used in this method. Commands and responses used in this method include an operation environment confirmation command C110, a power failure inactive response R160, and a power failure active response R160.
170 is shown. Active response at power failure R170
Contains data on power consumption.

The process executed by the terminal control circuit 36 of the branching device 30 using the message code shown in FIG. 11 will be described with reference to FIG. The terminal control circuit 36 controls the terminal 5
The power supply control switch 382A for 0A is temporarily turned on (S21), the terminal 50A is started, and an operation environment confirmation command C11 for confirming the power failure operation and the necessity of power supply.
0 is transmitted to the terminal 50 (S22). In response to the command C110, the terminal 50A desiring to operate (activate) by power supply from the branching device 30 at the time of a power failure receives a power failure activation response R170 including information indicating a measure of power consumption shown in FIG. I will send it back.

The branching device 30 receives the response R170 (S23), stores the power consumption based on the information element (S24), turns off the power supply control switch 382A again (S25), and resets the remaining terminal ports. The confirmation processing is sequentially performed (S26 to S35).

The branching device 30 receives the response R170 (S23), stores the power consumption based on the information element (S24), turns off the power supply control switch 382A again (S25), and resets the remaining terminal ports. The confirmation processing is sequentially performed (S26 to S35).

Here, the purpose of integrating the power consumption for each terminal port and then turning off the power supply control switch 382 once (S25, S30, S35) is as follows.
If the total amount of power supply capacity for the terminals managed by the branching device 30 is not enough to drive all the terminals, the power supply control switch is turned on to sequentially supply power to the terminals that are determined to require power supply. The priority is assigned in the order in which the determination process is performed for the determination of the terminal port where the communication is performed, which may impair the object of the present invention (efficient power distribution). This is because, after totaling the powers to be supplied, comprehensive judgment processing is performed, and the power supply control switches 382A to 382C of the appropriate terminal ports are selected and turned on (S36).

The message code C shown in FIG.
It is also conceivable to add an information element indicating a terminal type (division such as voice terminal or data communication terminal) to 110, and to manage the priority to be supplied with power according to the terminal type / type in step S36.

As means for detecting the power required by the terminal, it can be realized by subdividing the analysis function of the conduction detection circuit 317 shown in FIGS. 8 and 9 to detect a plurality of power instruction values. .

Further, as shown in FIG. 4, in a branching device having a plurality of power receiving interfaces, such as a power receiving circuit 371 and a power receiving circuit 372, when the power receiving circuit 371 is operated as a power supply, the backup power supply operating state at the time of a power failure is determined. Judgment, when the power receiving circuit 372 is operated as a power source, the operation state is determined to be the commercial power supply, and the total amount of available power is changed to increase or decrease the number of terminal ports to be supplied with power. A configuration suitable for the power supply capacity of the power supply circuit outside the device can be taken.

Next, referring to FIG. 13, when it is assumed that all the terminals accommodated in the branching device do not need to supply power and do not need to form a communicable state at the time of a power failure, the branching device is set to a low level. A description will be given of a system in which the power supply mode and the communication signal are bypassed to the branch device and relayed to a subsequent branch device or terminal in the power consumption mode.

FIG. 13 shows a branching device 30 having a function of detecting the operating environment of a terminal (whether power is required or not during a power failure) and the aforementioned power supply and communication signal bypass means.
FIG. 3 is a diagram showing the configuration of FIG. The branching device 30 having bypass means includes an upstream communication signal interface 32, a downstream communication signal interface 33, a terminal communication signal interface 34, an M bus control circuit 35, a terminal control circuit 36, and power receiving circuits 371 and 372. And a power supply control switch circuit 38, an upstream bypass switch 391, and a downstream bypass switch 392.

The upstream bypass switch 391 connects the signal line 70 connected to the upstream branching device or main device to
The switch selectively connects to the upstream communication signal interface 32 or the downstream bypass switch 392.
The downstream bypass switch 392 is a switch that selectively connects the signal line 70 connected to the downstream branching device to the downstream communication signal interface 33 or the upstream bypass switch 391.

The means (technique) shown in FIGS. 5 to 12 detects the operating environment of the terminal (whether it is necessary to supply power or whether there is an activation request at the time of a power failure) and the like. As a result, all of the terminals accommodated in the branching device 30 are detected. If the power supply is determined to be unnecessary in the event of a power outage and that there is no need to establish a communicable state,
Switch 38 of power supply control switch circuit 38 for terminal
2A and 382B are turned off, and the downstream bypass switch 392 is switched to the BP side in a bypass state (a state in which the communication line 70 is not connected to the transmission pulse transformer 333 and the reception pulse transformer 334 of the branch device 30). 30 to a deactivated state (standby state), the power supply from the upstream side and the communication signal are relayed to the downstream (subsequent) branching device, and the communication signal from the downstream side is transmitted to the upstream signal line. Relay to

The outline of the processing of the terminal control circuit 36 of the branching device 30 for controlling the above operation will be described with reference to FIG. The branching device 30 is powered on (POR) (S4
If there is 1), peripheral circuits and the like are initialized as initial settings (S42). Next, the drive power supply of the branching device 30 is:
It is determined whether the power source is a commercial power source or a backup power source during a power failure (in this embodiment, whether or not there is an output from the power receiving circuit 372) (S43). For example, the operating environment of the terminal (necessity of power supply or presence / absence of an activation request at the time of power failure) is detected by means (method) shown in FIGS. 5 to 12 (S44), and the result is transmitted to a power failure activation request as a non-volatile memory. Store in memory.

Further, based on the detection result, a power supply control switch 382A and a power supply control switch 382B for the terminal are provided.
Is controlled (S45). Next, the bypass switch 392 is turned off, that is, the transmission pulse transformer 333 and the reception pulse transformer 334 of the branching device 30 are connected to the communication line for the subsequent branching device (AC side) (S46). Branching device 30 and branching device 3
The terminal accommodated in 0 becomes available.

On the other hand, if the result of the determination in the step S43 is that there is no commercial power supply, that is, if a power failure has occurred, the power failure activation request, which is the content of the non-volatile memory stored in the power-on processing (S44), is checked ( S48) As a result of the determination, there is a power failure activation request, that is, as a result of inspection by the means (method) shown in FIGS. 2 to 12 in the energized state, one of the terminals requests activation or power supply at the time of power failure. Then, the power supply control switch 382 for the terminal is turned on to activate the terminal (S49).

Then, the bypass switch 392 is turned off, that is, the transmission pulse transformer 333 of the branching device 30 is turned off.
And the receiving pulse transformer 334 is connected to the communication line for the subsequent branching device (AC side) (S
46), the branching device 30 and the terminal accommodated in the branching device 30 can be used.

On the other hand, in step S48, as a result of the judgment of the power failure activation request memory, if none of the terminals has been activated at the time of the power failure or has not requested power supply, the power supply control switch circuit 38 is turned off (terminal Is stopped), and the bypass switch 392 is set to the BP side in a bypass state (a state in which the communication line is not connected to the transmission pulse transformer 333 and the reception pulse transformer 334 of the branching device 30) (S5).
0).

Further, since it is not necessary to activate the branching device 30, the operation of each functional unit in the branching device 30 is stopped to reduce the power consumption (S51) and shift to the standby state (S52). .

In this way, the power supplied from the upstream side and the communication signal are relayed to the subsequent branch device, and the power consumption of the inactive branch device 30 is greatly reduced. Further, communication in the power failure state is performed by a terminal connected to the branch device 30 other than the inactive state.

As described above, the description of the present invention is based on the assumption that a plurality of branching devices are connected in cascade to the upstream bus and the downstream bus connected to the main device, and communication is performed between the main device and the branching device using ATM cells. The ATM bus system according to the present invention employs such an ATM-M bus system.
Not only the M bus system, but also a bus for transmitting ATM cells starting from the main unit and returning to the main unit, and a bus for transmitting ATM cells.
The present invention can also be applied to an ATM bus system composed of two buses and having a plurality of branch devices connected to two buses.

The configuration of such an ATM bus system will be described with reference to FIG. The ATM-M bus system 1
A main device 10, a plurality of branching devices 30-1 to 30-3 connected to the ATM bus 70, and branching devices 30-1 to 30-
3 and the terminals 50-2A to 50-3A connected to the branching device 30-2, and the terminals 50-2A to 50-3A to be housed in the branching device 30-3 and the branching device 30-2. And a power adapter 90 that operates with a commercial power supply that supplies operating power to the power supply 50-2B.

The main unit 10 includes a connection unit for terminating the branching device of the ATM bus, a power supply circuit that can be backed up, and the like. The main device 10 includes the branching device 3
ATM bus (signal line) 7 comprising an up bus from 0 to the main unit 10 and a down bus from the main unit to the branch unit
0 is connected.

The first port P1 of the main unit 10 and the first branching device 30-1 are a signal line 70-1, and the first branching device 30-1 and the second branching device 30-2 are a signal line 70-1. -2
Thus, the second branching device 30-2 and the third branching device 30-3
Is a signal line 70-3, and the third branch device 30-3 and the second port P2 of the main device 10 are connected by a signal line 70-4. The signal line 70 has an up bus and a down bus, and is formed in a ring shape that exits from the main device and returns to the main device.

A signal line 70-1 connecting the main device 10 to the first branching device 30-1, a signal line 70-2 connecting the first branching device 30-1 to the second branching device 30-2, and A signal line 70-3 connecting the second branching device 30-2 and the third branching device 30-3, and a third branching device 30-
The signal line 70-4 connecting the device 3 and the main device 10 has a down bus and an up bus, respectively. The ATM cell loaded with the data for the branching device sent out from the main unit 10 on the down bus is sent to the main unit 1 downstream of the third branching device 30-3.
Returned to 0. From the main device 10 to the third branch device 30-3
Sent to the main unit 10
The ATM cell transferred to the first branching device 30-1 is returned to the main device 10 from the first branching device 30-1.

Further, the main device 10 and the first branch device 30
-1 is a feed line 75-1, and the second branch device 30-2 and the third branch device 30-3 are connected by a feed line 75-3, respectively.

The branching device 30-1 and the terminals 50-1A and 50-1
-1B is the interface cable 77-1A, 77-1
B, the branching device 30-2 and the terminals 50-2A and 50-2B
Are interface cables 77-2A and 77-2B.
The branching device 30-3 and the terminals 50-3A and 50-3B are connected by interface cables 77-3A and 77-3B, respectively.

Terminals 50-1A, 50-1B, 50-2
B and 50-3B are each supplied with electric power from a commercial power supply. The terminal 50-2A is transmitted from the branching device 30-2 to the terminal 50-2A.
-3A is supplied with power from the third branch device 30-3.

In this embodiment, the power supply circuit that can be backed up and mounted on main device 10 is connected to first branching device 30- via power supply line 75-1 via the connection unit.
1 is supplying power.

In this embodiment, the first branching device 30
-1 is supplied with power from the power supply circuit of the main device 10 via the power supply line 75-1, and the second branch device 30-2 is supplied with power from the power supply adapter 90 via the power supply line 75-2. You. Further, the third branch device 30-3 is supplied with electric power from the second branch device 30-2 via the feed line 75-3.

A power supply adapter 9 that operates on commercial power supply
0 is the second branching device 30- via the feed line 75-2.
2 is powered. The second branching device 30-2 uses the power received from the power adapter 90 to
0-2 itself is driven and its power is supplied to the power supply line 77-2PA of the interface cable 77-2A.
Terminal 50-2 accommodated in the branching device 30-2 via the
A, and is relayed to the third branching device 30-3 via the feed line 75-3.

Further, the third branching device 30-3 is connected to the second branching device 30-3.
The terminal 50 accommodated in the branch device 30-3 via the power supply line 77-3PA of the interface cable 77-3A while driving the branch device 30-3 itself with the power received from the branch device 30-2. -3A.

According to this embodiment, as in the first embodiment, by controlling the branching device by using the ATM cells of the ATM bus, not only the ATM-M bus but also the ATM is used.
Realizing that operating power is supplied to a branching device and a terminal connected to the branching device even in a bus in which the buses are connected in a ring, and whether power supply is necessary or not and a power capacity is managed for each branching device or terminal. Accordingly, the limited power supply power can be appropriately and effectively distributed and used in the communication system.

A configuration in a case where branching devices are connected to an ATM bus in a branching (tree-like) manner will be described with reference to FIG. The ATM-M bus system 1 includes a main unit 10 and an AT
A plurality of branching devices 30-1 to 30 connected to the M bus 70
-6, terminals 50-1A to 50-6B accommodated in the branching devices 30-1 to 30-6, and connected to the branching device 30-2 and accommodated in the branching device 30-2 itself and the branching device 30-2. A terminal 50-2A, a branching device 30-5, and a power adapter 90 that operates with a commercial power supply that supplies operating power to the terminal 50-5A connected to the branching device 30-5.

The main unit 10 includes a connection unit for terminating the branching device of the ATM bus, a power supply circuit that can be backed up, and the like. The main device 10 is connected to an ATM bus (signal line) 70 including an up bus from the subordinate branching device 30 to the main device 10 and a down bus from the main device to the subordinate branching device.

The first port P01 of the main unit 10 and the first branching unit 30-1 are a signal line 70-1, and the second port P02 of the main unit 10 and the second branching unit 30-2 are a signal line. 70-2. The first branch device 30-1 and the third branch device 30-3 are on a signal line 70-3, and the first branch device 30-1 and the fourth branch device 30-4 are on a signal line 7
0-4 are connected. The second branching device 30-2 and the fifth branching device 30-5 are on the signal line 70-5, and the second branching device 30-2 and the sixth branching device 30-6 are on the signal line 70-.
6 is connected. Each signal line 70 has an upstream bus from the branch device to the main device or a lower branch device to a higher branch device, and a downstream bus from the main device to a branch device or a higher branch device to a lower branch device. To form a branched (tree-shaped) ATM bus.

A signal line 70-1 connecting the main unit 10 and the first branching device 30-1, a signal line 70-2 connecting the first branching device 30-1 and the second branching device 30-2, and A signal line 70-3 connecting the second branching device 30-2 and the third branching device 30-3, and a third branching device 30-
The signal line 70-4 connecting the device 3 and the main device 10 has a down bus and an up bus, respectively.

The branching device 30-1 and the terminals 50-1A and 50-1
-1B is the interface cable 77-1A, 77-1
B, the branching device 30-2 and the terminals 50-2A and 50-2B
Are interface cables 77-2A and 77-2B.
The branching device 30-3 and the terminals 50-3A and 50-3B are interface cables 77-3A and 77-3B, and the branching device 30-4 and the terminals 50-4A and 50-4B are interface cables 77-4A and 77-4B. The branching device 30
-5 and terminals 50-5A and 50-5B are connected by interface cables 77-5A and 77-5B, and the branching device 30-6 and terminals 50-6A and 50-6B are connected by interface cables 77-6A and 77-6B. Is done.

Terminals 50-1A, 50-1B, 50-2
B, 50-3A, 50-3B, 50-4A, 50-4
B, 50-5B, 50-6A, and 50-6B are each supplied with electric power from a commercial power supply. The terminal 50-2A is supplied with power from the branching device 30-2, and the terminal 50-5A is supplied with power from the branching device 30-5.

In this embodiment, the power supply circuit that can be backed up and is mounted on the main device 10 is connected to the first branching device 30- via the power supply line 75-1 via the connection unit.
1 is supplying power.

In this embodiment, the first branching device 30
-1 is supplied with power from the power supply circuit of the main device 10 via the power supply line 75-1, and the second branch device 30-2 is supplied with power from the power supply adapter 90 via the power supply line 75-2. You. Further, the fifth branch device 30-5 is supplied with electric power from the second branch device 30-2 via the feed line 75-3.

Further, a power adapter 9 which operates on a commercial power supply
0 is the second branching device 30- via the feed line 75-2.
2 is powered. The second branching device 30-2 uses the power received from the power adapter 90 to
0-2 itself is driven and its power is supplied to the power supply line 77-2PA of the interface cable 77-2A.
Terminal 50-2 accommodated in the branching device 30-2 via the
A and is relayed to the fifth branching device 30-5 via the feed line 75-3.

Further, the fifth branching device 30-5 is connected to the second branching device 30-5.
The branching device 30-5 itself is driven by the power received from the branching device 30-2, and the terminal 50 accommodated in the branching device 30-5 via the feeder line 77-5PA of the interface cable 77-5A. -5A.

According to this embodiment, similarly to the first embodiment, by controlling the branching device using the ATM cells on the ATM bus, not only the ATM-M bus but also A
Even on a bus in which TM buses are connected in a tree shape, it is possible to supply operating power to branching devices and terminals connected to the branching devices, and manage the necessity of power supply and power capacity for each branching device and terminal. By doing so, it is possible to appropriately and effectively allocate and use the limited power supply in the communication system.

[0118]

As described above, according to the present invention,
By providing an operating power supply to a branching device or a terminal in an ATM bus system or an ATM-M bus system, and managing the necessity of power supply and the power capacity for each branching device or terminal, a communication system can be realized. The limited power supply can be allocated and used appropriately and effectively.

This has the advantage of reducing the configuration scale and operation cost of a backup power supply (such as a storage battery) in a communication system, especially during a power failure.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a connection system of an ATM-M bus system.

FIG. 2 is a block diagram showing a connection between a communication signal interface and a power transmission interface of a main device and a communication signal interface and a power reception interface of a branch device.

FIG. 3 is a block diagram illustrating an example in which a communication signal interface and a power transmission interface of a branching device, and a communication signal interface and a power reception interface of a terminal are connected by a phantom power supply method.

FIG. 4 is a block diagram showing a configuration of a branching device according to the present invention.

FIG. 5 is a block diagram illustrating a configuration of a branching device that detects an operating environment of a terminal using a detection signal line.

FIG. 6 is a diagram showing a coding example of a message signal for detecting an operation environment of a terminal.

FIG. 7 is a flowchart showing a control procedure for detecting the operating environment of the terminal using the message signal of FIG. 6;

FIG. 8 is a block diagram showing a configuration of a branching device that detects a power receiving terminal by an energization detection circuit.

FIG. 9 is a block diagram illustrating a configuration of a branching device that detects a non-power receiving terminal by an energization detection circuit.

FIG. 10 is a block diagram showing a configuration of a branching device obtained by subdividing the detection signal of FIG. 5;

FIG. 11 is a diagram illustrating an example of a message signal including a code indicating power consumption of a terminal.

12 is a flowchart showing a control procedure for collecting the operating environment of the terminal using the message signal shown in FIG. 11 and determining a power supply terminal.

FIG. 13 is a block diagram showing a configuration of a branching device that connects a power receiving interface and a power transmission interface according to the present invention and relays a communication signal and power supply to a subsequent branching device.

FIG. 14 is a flowchart showing a power outage control procedure in the branching device in FIG. 13;

FIG. 15 is a block diagram showing a connection system of an ATM-M bus system connected in a ring shape.

FIG. 16 is a block diagram showing a connection system of an ATM-M bus system connected in a tree shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Main apparatus 11 M bus connection unit 12 Communication signal interface 121 Transmitter 122 Receiver 123 Transmission side pulse transformer 124 Receiving side pulse transformer 14 Power transmission interface 19 Power supply (power transmission) circuit (backup) 30 Branching device 31 Power supply necessity determination means 311 Detection circuit 312 Detection resistor 313 to 316 Detection signal line 317 Energization detection circuit 32 Communication signal interface (upstream side) 321 transmitter 322 Receiver 323 Transmission side pulse transformer 324 Receiving side pulse transformer 33 Communication signal interface (Downstream side) 331 Transmitter 332 Receiver 333 Transmission-side pulse transformer 334 Reception-side pulse transformer 34 Communication signal interface (terminal side) 341 Transmitter 342 Receiver 343 Transmission-side pulse transformer 344 Reception-side pulse transformer S 35 M bus control circuit 36 Terminal control circuit 37, 371, 372 Power receiving circuit 38 Power supply control switch circuit 381 Power supply control switch for subsequent branch device 382 Terminal power supply control switch 391 Bypass switch (upstream side) 392 Bypass switch (downstream side) Reference Signs 50 terminal 51 communication signal interface 511 transmitter 512 receiver 513 transmission-side pulse transformer 514 reception-side pulse transformer 57 power supply circuit 58 power receiving circuit 59 battery 70 signal line 701 down line 702 up line 75 feed line 751, 752 line 77 interface cable 77P Power supply line 77S Signal line 90 Power adapter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junji Asakura 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo F-term within Nippon Telegraph and Telephone Corporation (reference) 5B011 EB03 FF03 5K030 HA10 KA11 KA23 5K032 BA04 DA20 DB01 DB31

Claims (14)

[Claims] In an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, a plurality of terminal ports and terminals connected to the terminal ports operate in the branching device. Power supply necessity determining means for determining whether or not to operate by receiving necessary power from the branching device side and power supply control means for controlling power supply to each terminal port are provided. To temporarily supply power via the power supply control means, determine whether or not the terminal connected to the terminal port operates by receiving power from the branch device side necessary for operating the terminal, An ATM bus system wherein power is supplied to only terminal ports to be supplied with power via the power supply control means. 2. In an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, a plurality of terminal ports and terminals connected to the terminal ports operate in the branching device. A power supply necessity determining means for determining whether or not the power supply operates from a required power supply from the branching device side; and directly connecting the upstream power supply line and the communication line with the downstream power supply line and the communication line. A bypass circuit is provided, and it is determined whether or not the terminal operates by receiving power required for operating the terminal from the branching device side, and all terminal ports of the branching device need not supply power from the branching device side. When it is determined that there is a power supply line, an ATM bus system connects an upstream power supply line and a communication line to a downstream power supply line and a communication line by the bypass circuit when a power failure occurs. 3. In an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, a power receiving interface for receiving power and transmitting the received power to a downstream side are provided to the branching devices. Power transmission interface,
An ATM bus system, comprising: a power supply interface for supplying power to itself and a terminal accommodated therein, and distributing power received from the power reception interface to the branching device itself, the power transmission interface, and the power supply interface. . 4. An ATM-M bus system in which one bus used as a downstream bus of an ATM bus is turned back downstream of the farthest branch device and connected to the other bus used as an upstream bus. Claim 1 to Claim 3
The ATM bus system according to any one of the above. 5. An ATM cell, wherein one of an upstream bus and a downstream bus of an ATM bus is used as an ATM cell transmission bus starting from the main unit and returning to the main unit, and the other bus starting from the main unit and returning to the main unit. 4. The ATM bus system according to claim 1, wherein the ATM bus system is a reception bus. 6. The ATM bus system according to claim 1, wherein the branching device is connected to an upstream bus and a downstream bus of an ATM bus connected in a tree from the main device. 7. A power supply necessity determination for determining whether a terminal to be operated at the time of a power failure is connected to a terminal or a terminal to be supplied with power in a terminal accommodating port provided in the branch device. 7. The ATM bus system according to claim 1, further comprising means. 8. A power supply necessity determining means provided in a branching device,
A function is provided to determine how much power required for the terminal connected to each terminal accommodating port to operate from the branching device is received. 8. The ATM bus system according to claim 7, wherein whether power is supplied to the terminal is controlled. 9. When it is determined that a terminal operated at the time of a power failure is not connected to any of the terminal accommodating ports, the power receiving interface and the power transmitting interface are connected by a bypass circuit, and power is relayed to another branch device. The ATM bus system according to any one of claims 1 to 6, wherein the ATM bus system is configured as described above. 10. A branching device used in an ATM bus system in which a plurality of branching devices are connected to an upstream bus and a downstream bus connected to a main device, a power receiving interface for receiving power, and transmitting the received power to a downstream side. A power transmission interface, a power supply interface for supplying power to itself and terminals accommodated therein, and a terminal connected to a terminal operated during a power failure among terminal accommodation ports, or which terminal is to be supplied with power is determined. A branching device for use in an ATM bus system, comprising power supply necessity determining means, and allocating power received from the power receiving interface to the branching device itself, the power transmission interface, and the power supply interface. 11. A power supply control method in an ATM bus system in which a plurality of branch devices are connected to an upstream bus and a downstream bus connected to a main device, wherein the branch device includes a plurality of terminal ports, and a terminal connected to the terminal port. Power supply necessity determination means for determining whether or not the power supply is required to operate by receiving power from the branching device side and determining whether or not the power supply is operated; and power supply control means for controlling power supply to each terminal port. Transmits a power failure operation command to confirm whether or not power supply is required from the power supply to each branch device during a power failure, and temporarily transmits each branch device to the terminal port via the power supply control means to the terminal port. A power supply control method in an ATM bus system, characterized in that power is supplied to a power supply and a response as to whether or not to receive power supply from a branch device in the event of a power failure. 12. The power supply control switch according to claim 11, wherein the power consumption of the branch device is mounted on a response from the branch device, and a power supply control switch of a port that can operate within a range of the power supply capacity of the main device is operated. Power supply control method in ATM bus system. 13. An ATM-M bus system in which one bus used as a downstream bus of an ATM bus is turned back downstream of the farthest branch device and connected to the other bus used as an upstream bus. The power supply control method in the ATM bus system according to claim 11 or 12. 14. An ATM cell, wherein one of an upstream bus and a downstream bus of the ATM bus is a bus for transmitting ATM cells starting from the main unit and returning to the main unit, and the other bus starting from the main unit and returning to the main unit. The power supply control method in the ATM bus system according to claim 11, wherein the power supply control method is a reception bus.