JPH0198357A - Common bus fault processing system - Google Patents

Abstract

PURPOSE:To attain location of a fault of a terminal controller and a common bus by switching the system into other system, and executing again the diagnosis in detecting a fault at the diagnosis from a central controller to each terminal controller. CONSTITUTION:Terminal controllers 190-220 receiving a terminal diagnosis command from a central controller 110 send a reply to a diagnosis command to the central controller 110. If the central controller detects a fault of a terminal controller 200 due to a faulty common bus 280, the central controller 110 commands the changeover of the system to an active/standby system controller 270 and sends a diagnostic command to the terminal controller 200 via the central controller 120 and the common bus 290 again. In such a case, since the bus 280 is faulty, the reply of the diagnosis command is normal and the central controller 120 discriminates the common bus 80 to be faulty.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in automatic switching equipment, and more particularly to a common bus failure handling scheme thereof.

(Prior Art) Conventionally, in an automatic switching system in which a central control unit and a terminal control unit are connected via a common bus, the central control unit sends a terminal diagnosis command to check the normality of processing in the terminal control unit. When a terminal diagnostic command is received by the terminal control device, the received information is retransmitted as is to the central control device.

The central control device monitors whether reply information from the terminal control device in response to the terminal diagnostic command is sent within a certain period of time, and determines whether the processing in the terminal control device is normal or abnormal.

Therefore, due to a hardware failure in the terminal control device,
Certain bits on the common bus were tied to a logic high or low level.

For this reason, even when normal data transmission/reception between the terminal control device and the central control device becomes impossible, the central control device determines that the terminal control device has failed.

(Problems to be Solved by the Invention) In the conventional common bus failure handling method described above, even if a common bus failure occurs, it is determined that the failure is in the terminal control device. The disadvantage is that all subordinate terminal control devices become unusable. Particularly, automatic switching systems using the active/standby operation system have the disadvantage that call services are degraded and are greatly affected.

An object of the present invention is to connect a central control device and a terminal control device via a common bus so that response information to information sent from the central control device to the terminal control device can be transmitted from the terminal control device within a certain period of time. To provide a common bus failure handling method configured to eliminate the above-mentioned drawbacks by monitoring whether or not transmission has been performed normally, and to be able to distinguish between a failure in a terminal control device and a failure in the common bus. be.

(Means for Solving the Problems) The common bus fault handling method according to the present invention is configured by comprising a plurality of terminal control devices, a pair of central control devices, a control device, and a plurality of interface devices. be.

Each of the plurality of terminal control devices is connected to a telephone set, and is used to transmit and receive information via a common bus.

A pair of central control units consists of an active system and a standby system, each connected to a storage device, with a number of terminal control units,
control the switching network, monitor whether the response information to the information sent to each terminal control device is normally transmitted from the terminal control device within a certain period of time, and control the common bus. This is to isolate the problem.

The controller is connected between a pair of central controllers,
This is to switch to the standby system if the active system has a failure based on the monitoring results.

The plurality of interface devices are for performing an interface regarding transmission and reception of information between each central control device and a common bus connected to each terminal control device.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram illustrating one embodiment of a common bus failure handling scheme according to the present invention.

In FIG. 1, 100 is a switching network;
110 and 120 are active and standby central controllers, 130 and 140 are active and standby storage devices, respectively, 190, 200, 210 and 220 are terminal control units, and 230, 240, 250 and 260 are terminal controllers, respectively. 150 and 160 are interface devices between the active central control device and the terminal control device, respectively, 170 and 180 are interface devices between the standby central control device and the terminal control device, respectively, 280,
290,300゜310 is the common bus, 270 is the active system/
This is a backup system control device.

Terminal control devices 190, 200, 210, and 220 control extension telephones 230, 240, 250, and 260, respectively, according to instructions from central control devices 110 and 120. Also, interface device 150.160.170.18
0 is the common bus 280.300.290.310 respectively
via terminal controller 200.2i0.220.19
It bridges the transmission and reception data from the central control units 110 and 120 to and from the central control units 110 and 120. Active system/standby system control device 27
0 performs switching control between the active system and standby system of the central controllers 110 and 120.

The active system central control device 110 is connected to each terminal control device 190.
．． In order to check whether 200.210.220 is operating normally, a terminal diagnosis command is periodically sent to each terminal control device.

FIG. 2 is an explanatory diagram showing the format of the terminal diagnosis command.

In Figure 2, the terminal diagnosis command is composed of a start mark, data length, command, first and second bit patterns, information on the accommodation position of the terminal control device, and an end mark. It is.

The start mark indicates the beginning of the command, and the data length indicates the total number of data in the command. The command is used to identify a terminal diagnosis command. The first and second bit patterns are common bus 280.300.290.31
It is used to check whether 0 is operating normally and contains (1) hidden patterns such as 0, OFFH, 55H, OAAH, etc. The housing position information is data regarding the housing position (for example, tool knit name and slot name) K of the terminal control devices 200, 210, 220, and 190.

The end mark indicates the end of the command.

Each terminal control device 190.2 that received the terminal diagnostic command
00, 210, and 220 rewrite the storage location information in the data of the terminal diagnosis command to the storage location information of the own device, and send the response to the terminal diagnosis command to the central controller 110.
, 120. Terminal control device 190, 20
The central control unit 110.120 that received the response data from 0°210.220 checks whether the response data matches the data content transmitted as the terminal diagnosis command. If the two match, it is determined that the terminal control device in question is operating normally, and the normality of the next terminal control device is checked.

Assume that a failure occurs in the hardware of terminal controller 200, resulting in a portion of the data signal lines of common bus 280 being held at a logical high level.

The active central control device 110 sends a terminal diagnosis command to the terminal control device 200.

However, because the common bus 280 is abnormal, the terminal control device 200 cannot receive the terminal diagnosis command, or even if the terminal control device 200 receives the terminal diagnosis command, the terminal control device 200 cannot receive the terminal diagnosis command.
The bit pattern data of the response data from the main controller 110 is different from that sent from the active central controller 110.

In order to identify whether the failure is in the terminal control device 200 or the common bus 280, the active system central control unit 110 checks the active system /
Switch the backup system.

That is, the contents of the active storage device 130 are transferred to the backup storage device 140 via the active/standby controller 270, and then the active central controller 110 transfers the contents to the active/standby controller 270. 270 to switch the system. the .

As a result, the standby system central control device 120 becomes the active system and sends the terminal diagnosis command to the terminal control device 200 via the common bus 290 again.

In this embodiment, since only the common bus 280 is out of order, the sending and receiving of terminal diagnostic commands via the common bus 290 is normal, and as a result, the central controller 120 can confirm that the terminal controller 200 is normal. , it can be determined that the common bus 280 is abnormal.

(Effects of the Invention) As explained above, the present invention, when an abnormality in the terminal control device is detected during diagnosis from the central control device to each terminal control device, executes switching of the system of the central control device and performs the system switching again in the other system. By diagnosing the above terminal control device, it is possible to isolate a failure between the terminal control device and the common bus, and there is an effect that it is possible to prevent a decline in call service even in the event of a failure of the common bus.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating one embodiment of a common bus failure handling scheme according to the present invention. FIG. 2 is an explanatory diagram showing the format of a terminal diagnosis command transmitted and received between the central control device and the terminal control device. 100...Switching network 110.120
... Central control device 130.140 ... Storage devices 150.160, 170, 180 ... Interface devices 190.200, 210.220 ... Terminal control device 2
30.240, 250.260...Extension telephone 270
...Control device 280, 290, 300, 310...Common bus patent applicant Hisashi Inoro, patent attorney for NEC Co., Ltd. Figure 21

Claims (1)

[Claims] It consists of a plurality of terminal control devices, each connected to a telephone set, for transmitting and receiving information via a common bus, and an active system and a standby system, each connected to a storage device, to control the plurality of terminal control devices and the switching network. Then, it monitors whether the response information to the information sent to each terminal control device is normally transmitted from the terminal control device within a certain period of time, and removes the fault on the common bus. a pair of central control devices for separating the central control devices; a control device connected between the pair of central control devices for switching to a standby system when the active system has a failure based on the result of the monitoring; and each of the central control devices 1. A common bus fault handling method comprising: a plurality of interface devices for performing an interface for transmitting and receiving the information with the common bus connected to each of the terminal control devices.