JPH06335036A - Subscriber circuit switching control circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding a system switching control circuit of a subscriber circuit in a digital exchange having a channel network of a duplex configuration that can operate independently, and to prevent malfunction of the subscriber circuit at system switching. And A subscriber circuit common section 11 for controlling a plurality of subscriber circuits 21 is provided corresponding to a duplicated speech path network 1, and a control signal sent from an operating speech path network is stored in the subscriber circuit common section. A system switching control circuit for a subscriber circuit of an exchange, which is temporarily stored in the section 12 and then sent to the subscriber circuit, wherein the content of the storage section when a system switching signal is received from the communication network in the subscriber circuit common section. A system switching control means 12 for sending an operation stop signal for stopping the operation according to the control signal to the subscriber circuit until it is updated, and for switching the subscriber circuit common part for controlling the subscriber circuit after the transmission is completed. The subscriber circuit is provided with the control signal suppressing means 22 for stopping the operation according to the control signal while the operation stop signal is being received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system switching control circuit for a subscriber circuit in a digital exchange having a duplexed speech path network which can operate independently.

In order to improve the reliability of a digital exchange, a control system and a communication path system that are commonly used have a dual structure, but a subscriber circuit and a circuit related circuit do not have a dual structure. Is normal.

As a method of mounting a subscriber circuit, a method of mounting a plurality of subscriber circuit packages each having a plurality of subscriber circuits on one subscriber circuit shelf is generally used. In many cases, a common control unit (hereinafter, referred to as a subscriber circuit common unit) that distributes or aggregates signals to a plurality of mounted subscriber circuit packages is provided.

The common part of the subscriber circuit is a signal to the subscriber circuit when a host device is switched between a duplex switch network (hereinafter referred to as a call network) and a single subscriber circuit. It also has a role of switching the route of the above, and is provided corresponding to the duplicated communication path network.

The above-mentioned signals include a voice signal and a control signal, both of which are signals in the direction from the subscriber circuit to the communication network (referred to as upstream) and in the direction from the communication network to the subscriber circuit. (Downward) signal. The control signal is called SCN signal in the up direction and SD signal in the down direction.
The SCN signal is a scanning signal for monitoring the status of the subscriber, and the SD signal is a signal for controlling the subscriber. The SD signal includes a call signal transmission instruction signal and the like, and if a wrong SD signal is transmitted to the subscriber circuit, an unnecessary call signal or the like is transmitted to the subscriber, causing annoyance. Particular attention is paid.

On the other hand, many subscriber circuit common parts have a structure in which voice signals and control signals are temporarily stored in a memory and then sent to the subscriber circuit (details will be described later). It is necessary to switch so that the contents of the memory being rewritten from the common part of the subscriber circuit will not be sent to the subscriber circuit as an erroneous SD signal when the system switching is performed.

[0007]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional bus type subscriber circuit signal system, and FIG. 6 is a diagram showing a multiplexing configuration of voice signal lines in a subscriber circuit shelf having the signal system configuration of FIG. 7 is a multiplexing configuration diagram of control signal lines in a subscriber circuit shelf of the same configuration, FIG. 8 is a configuration diagram of a conventional individual connection type subscriber circuit signal system, and FIG. 9 is a signal line configuration of FIG. Multiplexing configuration diagram of voice / control shared signal line in subscriber circuit shelf
10 is a time chart of the system switching operation of the subscriber circuit having the signal system configuration of FIG.

First, the signal system configuration of the subscriber circuit shown in FIG. 5 will be described with reference to FIGS. 6 and 7. In FIG. 5, the communication network is duplicated, and a signal line from the communication network to the subscriber circuit, that is, a voice signal highway (hereinafter referred to as a voice highway) and a control signal highway (hereinafter referred to as a control highway) are provided. 1 shows a signal line configuration of a subscriber circuit shelf connected to a plurality of subscriber circuit packages in a bus form.

Although only two sets of subscriber circuit shelves 30 out of a plurality of subscriber circuit shelves are shown in FIG.
Ten subscriber circuit packages (SLC) 40 are mounted on each subscriber circuit shelf 30. Each subscriber circuit package 40 is equipped with a plurality of, for example, 12 subscriber circuits (not shown), and one of the subscriber circuits is connected to the subscriber line, but the subscriber line side is not shown in the figure. However, only the exchange (call path network) side is shown. The subscriber circuit shelf 30 is provided with a subscriber circuit common unit (COM) 31 for commonly controlling a plurality of subscriber circuit packages 40 in association with both the 0-system and 1-system communication path networks 1.

In the above example, a voice highway for transmitting a digital voice signal of at least 120 time slots is required in the subscriber circuit shelf 30 for each direction.
34 is a voice highway for that purpose. This voice highway 34 is connected to the corresponding communication path network 1 via the 0-system and 1-system subscriber circuit common unit 31, but the subscriber circuit common unit 31
Since the line may be concentrated between the communication line network 1 and the voice network 1, the voice highway (H
WV) 4 and voice highway 34 in subscriber circuit shelf 30
Does not always have the same multiplexing configuration.

FIG. 5 shows a state in which the voice highway 4 from the communication network 1 is connected to a plurality of subscriber circuit shelves 30 in multiple ways. This shows the communication network 1 and the subscriber circuit shelves. An example of a case where a voice signal is concentrated between 30 is shown. However, since the method of concentrating the audio signal is not directly related to the present invention, detailed description will be omitted.

On the other hand, the control highway includes the control highway for the SCN signal (downward direction) for monitoring the state of the subscriber circuit and the control highway for the SD signal (downward direction) for controlling the subscriber circuit as described above. . One control highway is set to a plurality of subscriber circuit shelves 30 (for example, 16 shelves), and a control highway (HWS) 2 between the subscriber circuit common section 31 and the communication network 1 and the subscriber circuit shelves. The control highway 32 in 30 is generally of the same multiplexing configuration.

FIG. 6 is a diagram for explaining the structure of the voice highway (HWVL) 34 in the subscriber circuit shelf 30 in the structure of FIG. The subscriber circuit shelf 30 having the configuration shown in FIG. 5 has a total of 120 subscriber circuits when 10 subscriber circuit packages each having 12 subscriber circuits are mounted, so that the voice highway is 2 Mbit / sec. 4 highways (32 time slots each) for each direction
You will need a book.

FIG. 6 shows four audio highways HWVL _{0 to} HWVL _{3 each} having 32 time slots (TS) 120.
This is a configuration example in which the voice of the subscriber circuit of the circuit is multiplexed, and is common to the upstream and downstream directions. In this example, in addition to the subscriber circuit package 40, a total of 8 time slots are allocated to the time slot numbers 0 and 16 for voice signals required for testing in the subscriber circuit common section 31. The number 0 is the common part 31 of the subscriber circuit.
Shows the package.

FIG. 7 is a diagram for explaining the structure of the control highway (HWSL) 33 in the subscriber circuit shelf 30 in the structure of FIG. Unlike voice, the control signal can have a long period, so that the control signals of a large number of subscriber circuit shelves 30 can be multiplexed on one control highway. In FIG. 7, one control highway 2 is commonly used for 16 shelf (SH _{0 to} SH ₁₅ ) subscriber circuit shelves, but the control highway (HWS) between the communication network 1 and the subscriber circuit shelf 30 is used. 2 and the control highway 32 in the subscriber circuit shelf 30 have the same configuration.

As shown in FIG. 7C, the control signal is 4 bits for each subscriber circuit (C _{0 to} C ₁₁ indicate the number of a subscriber circuit (not shown) in each subscriber circuit package 40). Same subscriber circuit package using (a to d bits)
40 (P _{1 to} P _{10 in} FIG. 7 (b) indicate the numbers of the subscriber circuit packages 40) are continuously sent to 12 subscriber circuits. The package number P _{0 in} FIG. 7B is the package of the subscriber circuit common unit 31, but 8 sets (C _{0 to} C ₇₎ corresponding to the voice channel of FIG. ) Control signals (4 bits each) are assigned.

The control signals are SCN signals in the up direction and SD signals in the down direction, but the multiplexing structure is common. Hereinafter, an SD signal related to the present invention will be described.
In the configuration of FIG. 7, one subscriber circuit shelf 30, for example 0
Since the SD signal for the subscriber circuit shelf 30 (SH _{0 in} FIG. 7A) is input every 4 ms from the channel network 1 side, the SD signal once received by the subscriber circuit common section 31 is 4 ms later. It is valid until a new control signal is input.

In the above configuration, for example, when the 1-system communication path network 1 is set as the operating system, the SD signal is transmitted from the 1-system communication path network 1 to the control highway 2 having the multiplexing structure shown in FIG.
From each subscriber circuit shelf 30 1-system subscriber circuit common section
30 and is sent to each subscriber circuit package 40 from the control highway 32 in the same multiplexing shelf.

In this state, when the active communication network 1 is switched from the 1-system to the 0-system, the SD signal from the 1-system communication network 1 is stopped, and each subscriber starts from the 0-system communication network 1. The SD signal is sent to the 0-system subscriber circuit common section 30 of the circuit shelf 30. Some exchanges send SD signals of the same content from both the active communication path network 1 and the standby communication path network 1 to the corresponding subscriber circuit common part 31, but in this case, of course, SD only from the communication network
Even in a switching system that sends a signal, the system switching in the communication path network 1 is instantaneously performed, so that there is no risk that an erroneous SD signal is sent to the subscriber circuit when switching.

However, in the configuration of the signal line of FIG. 5, the control highway shown in FIG. 7 is connected to each subscriber circuit package 40 in a bus form, so that one of the subscriber circuit packages 40 is inserted or removed for some reason. Then control highway 32
Noise may occur on the top. If this noise is input to another subscriber circuit package 40, the worst case is 4 ms.
During the period, malfunctions such as sending a calling signal or locking the operation may occur to the subscribers connected to the subscriber circuit on the subscriber circuit package. Further, due to a failure of the control signal input section or output section (neither shown) of one subscriber circuit package 40,
It is also conceivable that the control highway 32 in the form of a bus will be stuck at the H level or the L level and all the subscriber circuit packages 40 of the subscriber circuit shelf 30 will be out of control.

That is, in the bus configuration shown in FIG. 5, there is a high possibility that the subscriber circuit will malfunction when the subscriber circuit package 40 is inserted or removed with power being supplied. Therefore, maintenance such as subscriber circuit package replacement is required. There is a drawback that the work is troublesome.

FIG. 8 is a signal line configuration diagram of a subscriber circuit of the prior art in which this drawback is prevented. In the case of FIG. 8, the control highway in the subscriber circuit shelf 50 is not provided as a bus type but is individually provided for each subscriber circuit package 60 from the subscriber circuit common section 51. In this way, the signal line is connected to the subscriber circuit package.
With the configuration provided separately for each 60, even if one of the subscriber circuit packages 60 is inserted or removed, or a control highway stack failure occurs, the control signals supplied to the other subscriber circuit packages 60 will be affected. There is no.

On the other hand, in this format, if the control highway and the voice highway are provided separately for each subscriber circuit package 60, the wiring amount in the subscriber circuit shelf 50 increases, so that the control signal and the voice signal are transmitted on the same highway. In general, the signal highway 55 in FIG. 8 is a highway in which a control signal and a voice signal are multiplexed on the same highway.

FIG. 9 shows a multiplexing structure of the signal highway 55. As shown in the figure, the voice signal (V) and the control signal (S) for the twelve subscriber circuits (C _{0 to} C ₁₁ ) in each subscriber circuit package 60 are arranged in consecutive 8-bit time slots. ing. The control signal is normally composed of 4 bits a to d for both the SCN signal and the SD signal, but in the configuration shown in the figure, the remaining 4 bits are used for a spare or other purpose signal.

The control signal and the voice signal are transmitted and received via the voice highway 4 and the control highway 2 from the communication network 1, respectively. The control highway 2 has the same multiplexing structure as that shown in FIG. is there. As shown in FIG. 7, the period of the control signal for one subscriber circuit is 4 ms, while the period of the voice signal is 125 μs.
In order to arrange the control signal and the voice signal for the same subscriber circuit as shown in FIG. 9, it is necessary to temporarily store the control signal and the voice signal in the memory and rearrange them. The memory (MEM) 52 in the subscriber circuit common unit 51 of FIG. 8 is provided for that purpose, but the control signal multiplexed on the signal highway 55 by this memory 52 must be updated every 125 μs. Therefore, even if a momentary noise occurs due to lightning or the like input from the subscriber line side (not shown), the relay in the subscriber circuit will not malfunction.

Next, the operation of the control signal when the communication channel network 1 of the operating system is switched from the 1 system to the 0 system in the configuration of FIG. 8 will be described. In the conventional duplex system having the configuration shown in FIG. 8, signals of the same contents are sent from the communication path network 1, which is a higher-level device, to the subscriber circuit shelf 50 to the operating control highway 2 and the standby control highway 2. There is. That is, the memory 52 of the 0-system subscriber circuit common unit 51 and the memory 52 of the 1-system subscriber circuit common unit 51 always have the same SD contents.
The subscriber circuit common unit 51, which stores the signal and is connected to the active communication network 1, is set to the operating state and sends the SD signal to each subscriber circuit package 60. Therefore, when the 1-system channel network 1 is switched from the operating system to the standby system, the 1-system subscriber circuit common unit 51 becomes the standby system,
Even if the 0-system subscriber circuit common unit 51 becomes the operating system, the control signals supplied to the respective subscriber circuit packages 60 do not lose continuity and malfunction does not occur.

However, in the duplex configuration of such a system, the standby communication channel network 1 must also perform the same operation as the active communication channel network 1, so that it is newly accommodated in the communication channel network 1. When a device is tested in advance, a loopback test or the like cannot be performed from the test device by using the backup communication channel network 1. For this reason, it is necessary to provide a duplex configuration in which the standby communication channel network 1 can be freely tested by separating it from the operation of the active communication channel network 1.

However, if the communication path network 1 of the operation system and the protection system is made to be able to operate independently, the contents of the control signal stored in the memory 52 of the subscriber circuit common part 51 of the operation system and the protection The contents of the control signals stored in the memory 52 of the subscriber circuit common unit 51 of the system cannot always be matched. Hereinafter, this point will be described with reference to FIG.

FIG. 10 is a time chart of the system switching operation when the communication path network 1 of the operating system and the protection system is operated independently in the configuration of FIG. 8 from the operation system 1 of the communication path network 1 to the protection system. This is illustrated in the case of switching. In the figure, ACT and SBY show the states of the operating system and the standby system, respectively, and a _{11 to} a ₁₄ and b _{11 to} b ₁₄ show the operating states of the parts indicated by the same symbols in FIG. .

When the 1-system communication network 1 (NW1) is set as the active system and the 0-system communication network 1 (NW0) is set as the standby system, the 0-system communication network 1 is set to the 0 system. Subscriber circuit common section
SBY as the system status information for 51 is the communication network 1 of the 1 system
System status information ACT for the 1-system subscriber circuit common section 51
Has been sent (a ₁₁ , b ₁₁ ).

In this state, the 1-system subscriber circuit common section 51 and the signal highway 55 in the subscriber circuit shelf 30 are connected to the connection section 54.
(B ₁₃ ), the control signal (SD signal) sent from the 1-system communication path network 1 to the memory 52 of the 1-system subscriber circuit common section 51 via the control highway 2 is the memory 52. (B ₁₂ ) after being temporarily stored in the voice highway 4
It is multiplexed with the audio signal input to the memory via the signal shown in FIG. The multiplexed SD signal is sent from the connection section 55 to each subscriber circuit package 60 via the signal highway 55.

The subscriber circuit common section 51 is the corresponding communication network 1.
Further, when ACT is received as system status information and the common unit is sending a control signal to the subscriber circuit package 60, the system status information is sent to the subscriber circuit common unit 51 of another system. Since the system status information ACT is transmitted via the line 57, in the above-mentioned state, the system status information ACT is sent from the 1-system subscriber circuit common unit 51 to the 0-system subscriber circuit common unit 51. It is being sent (b ₁₄ ). At this time, the state of the 0-system subscriber circuit common unit 51 side is completely opposite to the 1-system side as shown in FIG. 10 (a _{11 to} a ₁₄ ).

When the active communication channel network 1 is switched from the 1-system to the 0-system in the above state, the system status information for the 0-system communication circuit network 1 to the 0-system subscriber circuit common unit 51 is changed from SBY to A.
In the CT, the common part of the subscriber circuit of the system 1 from the communication network 1 of the system 1
System status information for 51 changes from ACT to SBY (a
₁₁ , b ₁₁ ).

Since this change serves as a system switching signal for instructing system switching, the 1-system subscriber circuit common unit 51 disconnects the signal line to the subscriber circuit package 60 and the 0-system subscriber circuit common unit. 51 connects the signal line to the subscriber circuit package 60 (a ₁₃ , b ₁₃ ). At the same time, the system state information for the common circuit 51 of the other subscriber is changed (a ₁₄ , b ₁₄ ).

At the same time as system switching, the SD signal is no longer sent to the control highway 2 from the 1-system communication path network 1,
SD for control highway 2 from 0-system communication network 1
The signal will be sent. However, as apparent from FIG. 7, it takes a certain time (4 ms in the example of FIG. 7) until all the control signals of the operating system are stored in the memory 52 of the 0-system subscriber circuit common unit 51. Immediately after the switching, the information stored in the memory 52 when it is the standby system is sent from the 0-system subscriber circuit common unit 51 to the subscriber circuit package 60 (a ₁₂ ).

The information stored in the memory 52 when the system was the standby system is the S stored when the system was previously operating.
Since the content is indefinite such as the D signal, some signal or noise transmitted from the standby communication network 1, there is a high possibility that an erroneous signal is transmitted to the subscriber via the subscriber circuit. . That is, when the operating system and the standby system 1 are operated independently in the configuration of FIG. 8, there arises a problem that an erroneous signal is sent to the subscriber when the system is switched.

[0037]

As described above, in the digital exchange of the prior art, the subscriber circuit is configured so that the subscriber circuit package can be inserted / removed while the power is supplied, and the duplexer has a dual structure. If the communication network is operated independently, the subscriber circuit may malfunction when the operating system and the standby system are switched in the communication network. For this reason, it is not possible to independently operate the duplexed speech path network, and it is impossible to conduct a connection test using the standby speech path network, which hinders maintenance work.

It is an object of the present invention to prevent malfunction of a subscriber circuit at the time of system switching in a digital exchange having a redundantly constructed speech path network which can operate independently.

[0039]

FIG. 1 is a basic configuration diagram of the present invention. In the figure, 1 is a duplexed speech path network, 21 is a plurality of subscriber circuits, 11 is a subscriber circuit common section provided for the duplicated speech path network 1 and controlling a plurality of subscriber circuits 21, 12 Is provided inside the subscriber circuit common section 11 and temporarily stores the control signal sent from the call path network 1 when the corresponding call path network 1 is set to the operating system, and then sends it to the corresponding subscriber circuit 21. It is a storage unit.

13 is provided in each subscriber circuit common section 11,
When receiving a system switching signal notifying the switching between the active system and the standby system from the corresponding communication network 1, it cooperates with the subscriber circuit common section 11 of the other system to newly set the communication network. Until the control signal stored in the storage unit 12 of the subscriber circuit common unit 11 corresponding to 1 is updated, an operation stop signal for stopping the operation according to the control signal is sent to the plurality of subscriber circuits 21. , System switching control means for controlling the subscriber circuit 21 to switch between the operation system and the standby system of the subscriber circuit common unit 11 after the transmission is completed.

Reference numeral 22 is provided in each of the plurality of subscriber circuits 21 to receive an operation stop signal, and while the operation stop signal is being received, an operation according to a control signal received from the subscriber circuit common section 11 to the own subscriber circuit 21 is performed. It is a control signal suppressing means for controlling to stop.

[0042]

FIG. 1 shows the configuration of the signal system of the subscriber circuit portion of the digital exchange in which the communication network 1 has a duplex structure and the subscriber circuit has a simple structure.

The subscriber circuit common unit 11 corresponding to the communication path network 1 set in the operating system temporarily stores the control signal received from the operating system communication path network 1 in the storage unit 12, and then a plurality of controlled objects are controlled. It is being sent to the subscriber circuit 21.

When the operating system and the standby system of the communication network 1 are switched in this state, a system switching signal is sent from the communication network 1 of both systems to the corresponding subscriber circuit common section 11, and at the same time the operating system is operated. The control signal from the communication path network 1 set to 1 is stopped, and a new control signal is sent from the communication path network 1 set to the standby system. Along with this, a new control signal is no longer stored in the storage unit 12 in the subscriber circuit common unit 11 that was the operating system up to now, and conversely the storage in the subscriber circuit common unit 11 that was the standby system. The new control signal begins to be stored in section 12.

When the system switching signal is received, the system switching control means 13 in the subscriber circuit common section 11 of both systems starts the system switching operation, but the control signal is sent to the subscriber circuit 21 in the operating system. The existing subscriber circuit common unit 11 continues for a while.
However, the storage unit 12 of the subscriber circuit common unit 11 that was the operating system
Since no new control signal is stored in, the signal sent to the subscriber circuit 21 will be incomplete.

Further, when the system switching signal is received, the system switching control means 13 of either one of the subscriber circuit common parts (for example, the subscriber circuit common part which was the operating system) 11 has a plurality of subscriber circuits. An operation stop signal is sent to the device. This operation stop signal is sent until the control signal stored in the storage section 12 of the subscriber circuit common section 11 corresponding to the speech network 1 newly set in the operation system is updated.

Control signal suppressing means 22 for a plurality of subscriber circuits 21
Receives an operation stop signal together with the incomplete control signal, and controls so as to stop the operation according to the received control signal. Therefore, the subscriber circuit 21 does not malfunction due to an incomplete control signal while receiving the operation stop signal.

Since the time until a new control signal is completely stored in the storage section 12 in the subscriber circuit common section 11 which has been switched from the standby system to the operating system is predetermined, when this time elapses, both systems are joined. System switching control means 13 in the common circuit common section 11
Controls to stop the operation stop signal by the cooperative operation, and at the same time, to send a control signal from the storage unit 12 of the subscriber circuit common unit 11 corresponding to the communication network 1 newly set in the operation system. As a result, the subscriber circuit common unit 11 that sends a control signal to the subscriber circuit 21 is switched, and the system switching operation is completed.

As described above, in the configuration of FIG. 1, even if the duplexed channel network operates independently, an erroneous control signal is sent to the subscriber circuit 21 when switching between the active system and the standby system. Never.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is a configuration diagram of a subscriber circuit signal line multiplexing embodiment of the present invention, and FIG. 4 is a system switching operation time chart of an embodiment of the present invention.

Throughout the drawings, the same reference numerals denote the same objects, 1 is a duplex communication network, 2 is a control highway,
3 is a system switching signal line, 10 is a subscriber circuit shelf, 11 is a subscriber circuit common section, 12 is a memory (a form of realization of the storage section 12 in FIG. 1), 13 is a system switching control section (system switching control in FIG. 1) Means 13), 14 is a connection portion, 15 is a signal highway in the subscriber circuit shelf 10, 16 is an operation stop signal line (DTFZ line),
Reference numeral 17 is a system status notification line, 20 is a subscriber circuit package, 21 is a subscriber circuit, 22 is a control signal suppressing unit, and 23 is a control circuit.
The function of the control signal suppressing means 22 of FIG. 1 is realized by a combination of the control signal suppressing unit 22 and the control circuit 23.

In the configuration of FIG. 2, the communication path network 1 is a duplex configuration,
Although the subscriber circuit 21 has a single structure, a subscriber circuit common section 11 for controlling the subscriber circuit 21 in the subscriber circuit shelf 10 is provided corresponding to the communication network 1. The multiplexing structure of the control highway 2 is the same as that shown in FIG. 7, and when there are a plurality of subscriber circuit shelves 10, control is performed for a fixed number (16 shelves in the structure of FIG. 7) of subscriber circuit shelves 10. One highway 2 is set.

The control signal sent from the control highway 2 is multiplexed in the subscriber circuit common unit 11 and sent to the signal highway 15 as described later. Signal Highway 15
One is set for each subscriber circuit package 21, but since it is not duplicated, it is shared by the subscriber circuit common section 11 of the two systems, but one of the subscriber circuit common sections 11 is connected by the connection section 14. Used only connected with.

Hereinafter, the switching operation between the operating system and the standby system in the above configuration will be described with reference to FIG. 4, but the portions overlapping with the conventional technique described with reference to FIG. 8 will be briefly described. It should be noted that a _{1 to} a ₅ and b _{1 to} b ₅ in FIG. 4 indicate the operating states of the portions denoted by the same reference numerals in FIG.

Now, assuming that the 1-system communication channel network 1 (NW0) is set as the active system and the 0-system communication channel network 1 (NW1) is set as the standby system, the 0-system communication channel network 1 is set as the 0-system. The system state information SBY of the low level signal is 1 for the subscriber circuit common section 11 of
The system state information ACT of the high level signal is sent from the system communication network 1 to the subscriber circuit common part 51 of the system ₁ (a ₁ ,
b ₁ ).

System switching control unit of the 1-system subscriber circuit common unit 11
13 receives the system status information ACT and activates the connection unit 14, so that the 1-system subscriber circuit common unit 11 and the signal highway 15 are connected (b ₃ ). On the contrary, the 0-system subscriber circuit common section 11 and the signal highway 15 are separated from each other at the connection section 14 (a ₃ ).

The 1-system subscriber circuit common section 11 temporarily stores in the memory 12 the control signal (hereinafter, only SD signal) sent from the 1-system communication path network 1 via the control highway 2 and then the connection section. In FIG. 14, as shown in FIG. 9A, a voice signal (not shown in FIG. 2) is combined and multiplexed, and the signal is sent to the signal highway 15 (b ₂ , b ₃ ). At this time, 0
Information previously stored in the memory 12 of the subscriber circuit common part 11 of the system, or information transmitted when the 0-system communication network 1 performs some operation (for example, a test) Although SBY information is written in FIG. 4), it is incomplete information in any case (a ₂ ).

The system switching control unit 13 of the subscriber circuit common unit 11 receives the system status information ACT from the corresponding communication network 1, and the own common unit establishes the connection state with the signal highway 15 for the subscriber circuit package 20. At some time, the system status information ACT is sent to the system switching control unit 13 of the other system via the system status notification line 17. In the above state, ACT from the system switching control unit 13 of the 1 system,
SBY is sent from the 0-system switching controller 13 (a
₅ , b ₅ ).

When the operating system and the standby system of the communication network 1 are switched in this state, the system state information of the system switching signal line 3 of the 0 system changes from SBY to ACT and the system of the system switching signal line 3 of the 1 system is changed. The status information changes from ACT to SBY (a ₁ , b ₁ ). This change becomes a system switching signal instructing system switching, and the subscriber circuit common unit 11 starts the system switching operation.

First, the system switching control unit 13 of the subscriber circuit common unit 11 of the first system, which was the operating system, stops the operation (data freeze) signal line (hereinafter referred to as DTFZ line) via the connection unit 14.
Operation stop signal for 16 (hereinafter referred to as DTFZ signal)
(B ₄ ) but at this point the signal highway 15
Keeps the previous state, that is, the connected state (b ₃ ). Therefore, for the system status notification line 17, ACT is used as system status information.
The information remains to be sent (b ₅ ).

Also, the system switching control unit 13 of the 0-system subscriber circuit common unit 11 does not immediately connect to the signal highway 15 at the time of receiving the system switching signal and maintains the previous state (a ₃ ). , And continues to send the system status information SBY to the system status notification line 17 (a ₅ ). However, after receiving the system switching signal, 0
Since a control signal for the operating system from the communication network 1 starts to be input to the common subscriber circuit section 11 of the system via the control highway 2, the contents of the memory 12 are gradually rewritten to the control information of the operating system (a ₂ ).

A preset time from the reception of the system switching signal,
More specifically, when a sufficient amount of time has passed to completely rewrite the contents of the 0-system memory 12 with the contents of the operating-system control signals, 0
The system switching control unit 13 of the system sends an ACT from the system status notification line 17 to the system switching control unit 13 of the 1st system to notify that the own system becomes operable (a ₅ ).

Upon receiving the ACT information, the system switching control unit 13 of the 1 system controls the connection unit 14 to control the common unit and the signal highway.
15 is disconnected (b ₃ ), and the system status information sent to the system status notification line 17 is changed from ACT to SBY (b ₅ ),
At the same time, the DTFZ signal sent to the DTFZ line 16 is stopped (b ₄ ).

The system switching control unit 13 of the 0 system is the system switching signal line 3 from the corresponding communication network 1, and the subscriber circuit common unit 11 of the other system.
When the ACT is received from both of the system status notification lines 17, the connection section 14 is controlled and the own common section 11 is set to the signal highway.
It is connected to 15 (a ₃ ), and the control signal of the operation system stored in the memory 12 is sent to the subscriber circuit 21 side. At this point, the system switching is completed.

As is clear from the above, the SD signal stored in the memory 12 of the subscriber circuit common section 11 of the system 1 which has been in the operating system from the start of the system switching to the completion of the system switching is the subscriber circuit. It is sent to the 21 side. Since the SD signal as the operating system is not sent to the subscriber circuit common section 11 of the 1 system from the time when the system switching is started, the memory of the subscriber circuit common section 11 of the 1 system is
The SD signal sent from 12 to the subscriber circuit 21 has incomplete contents.

The subscriber circuit 21 receives the incomplete SD signal via the signal highway 15 from the time when the system switching is started to the time when the system switching is completed. The subscriber circuit 21 normally performs an operation required by the control circuit 23 (for example, a calling signal sending operation) by the SD signal received from the signal highway 15. In the above case, as shown in FIG. Since the DTFZ signal is sent to the control signal suppressing section 22 of the master circuit 21, the control signal suppressing section 22 controls the control circuit 23 so as not to perform the operation according to the control signal. Therefore, the subscriber circuit
The 21 does not malfunction due to an incomplete SD signal.

In the above description, the DTFZ signal is sent from the subscriber circuit common section 11 to the subscriber circuit 4 via the DTFZ line 16, but the DTFZ signal is not an individual signal line but is superimposed on the signal highway 15. It is possible to

FIG. 3 shows an embodiment of the structure of the signal highway 15 on which the DTFZ signal is superimposed. As shown in FIG. 3B, the SD signal is generally composed of 4 bits, but in the structure of FIG. 3, 8 bits are allocated for the control signal, so that there is a margin of 4 bits. Therefore, if 1 or 2 bits of the remaining 4 bits are assigned to the DTFZ signal, it is not necessary to provide a separate signal line for the DTFZ signal. FIG. 3B shows an example in which 1 bit is assigned to the DTFZ signal.

Although the embodiment of the present invention has been described with reference to FIGS. 2 to 4, FIGS. 2 to 4 merely show one embodiment of the present invention, and only the embodiment of the present invention is shown. It goes without saying that it is not limited to. For example, the internal structures of the subscriber circuit common unit 11, the subscriber circuit package 20, and the subscriber circuit 21 in FIG. 2 are illustrated only for relevant parts for convenience of explanation, but actually various configurations are possible. Therefore, the effect of the present invention does not change even if these configurations are changed.

Further, the communication network 1 and the subscriber circuit shelf 10
It is also clear that the effect of the present invention does not change even if the system switching signal line 3 between them is not an independent signal line but is superposed on the control highway 2, for example. Further, there may be many signal multiplexing methods and multiplex numbers other than those shown in FIGS. 3 and 4, but it goes without saying that the effects of the present invention do not change due to these changes.

[0071]

As described above, according to the present invention,
In a digital exchange designed to allow insertion / removal of a subscriber circuit package while power is being supplied, when the duplexed channel network is configured to operate independently, the channel network operation system and standby There is no malfunction of the subscriber circuit when switching the system. For this reason, it becomes possible to perform tests and the like using the backup channel, which greatly contributes to the improvement of maintainability and reliability of the exchange.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a block diagram of an embodiment of the present invention.

FIG. 3 is a block diagram of signal line multiplexing of a subscriber circuit according to an embodiment of the present invention.

FIG. 4 is a time chart of a system switching operation according to an embodiment of the present invention.

FIG. 5 is a conventional circuit diagram of a subscriber circuit signal system (bus format).

FIG. 6 is a configuration diagram of voice signal line multiplexing of a subscriber circuit according to the related art.

FIG. 7 is a prior art subscriber circuit control signal line multiplexing configuration diagram.

FIG. 8 is a conventional circuit diagram of a subscriber circuit signal system (individual connection format)

FIG. 9 is a configuration diagram of a subscriber circuit signal line multiplexing according to the related art.

FIG. 10 is a time chart of a system switching operation according to the related art.

[Explanation of Codes] 1 Channel network 11 Subscriber circuit common section 12 Storage section 13 System switching control means 21 Subscriber circuit 22 Control signal suppressing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kawa ▲ saki ▼ Yuya 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Sachiko Inoue 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Stock In the company

Claims (1)

[Claims] 1. A call line network (1) provided with a subscriber line common section (11) for controlling a plurality of subscriber circuits (21) corresponding to a duplicated call line network (1) and set as an operating system (1). A storage unit (12) internally provided with a control signal sent from the communication network (1) to the plurality of subscriber circuits (21) by the subscriber circuit common unit (11) corresponding to 1). A system switching control circuit of a subscriber circuit in a digital exchange configured to be temporarily stored in the subscriber circuit (21) and then sent to the plurality of subscriber circuits (21). Communication network
(1) When receiving the system switching signal notifying the switching between the active system and the standby system, it operates in cooperation with the common part of the subscriber circuit of the other system (11), and the communication path network newly set in the active system ( Operation according to the control signal for the plurality of subscriber circuits (21) until the control signal stored in the storage section (12) of the subscriber circuit common section (11) corresponding to 1) is updated A system switching control means (13) for sending an operation stop signal for stopping the operation of the subscriber circuit (21) for controlling the subscriber circuit (21) after the transmission is completed and for controlling to switch between the operating system and the standby system. In the plurality of subscriber circuits (21), while receiving the operation stop signal and receiving the operation stop signal, own subscriber circuit (21)
Control signal suppressing means (22) for controlling so as to stop the operation according to the control signal received from the subscriber circuit common section (11).
A system switching control circuit for a subscriber circuit, comprising: