JPH05244265A - Communication system - Google Patents

Abstract

PURPOSE:To obtain the communication system capable of grasping a fault of a transmission line accurately and securing stable transmission quality at all times. CONSTITUTION:A detection time of a code error caused on a line from a digital PBX 1 to a digital telephone set DP1 is sent to the PBX 1 as error occurrence information and the PBX 1 stores the error occurrence information to a storage circuit 13 and when number of times of occurrence of the code error exceeds a prescribed value, a maintenance terminal equipment 17 displays an error.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system such as a private branch exchange system in which a specific communication device among a plurality of communication devices is a master and another communication device is a slave.

[0002]

2. Description of the Related Art In recent years, construction of a system using a digital exchange (digital PBX) has been promoted as one of private branch exchange systems, and will become the mainstream in the future with the spread of ISDN (Integrated Service Digital Network). Thought to be a thing. This type of system converts an analog signal such as voice into a digital signal and performs time-division-multiplexing and then exchange control.Using an extension terminal having an original digital interface such as a digital telephone,
Communication by composite data in which voice and data are integrated becomes possible.

In the private branch exchange system, for example, when data is transferred from the PBX side to the digital telephone side, an error detection code for detecting a code error generally generated in the process of propagating through the transmission line is included in this transmission data. Is added and transmitted. The digital telephone side checks whether or not a code error has occurred in the received data based on the error detection code in the received data, and discards the data in which the code error has occurred.

[0004]

However, in such a conventional private branch exchange system, generally, when a transmission error occurs on the digital telephone side, the data is simply discarded and the transmission error occurs. Has not been reported to the outside. For this reason, even if a code error occurs in the data transferred from the PBX side, the PBX side may be overlooked without noticing the occurrence of the code error itself. As a result, even if there is a factor that causes a code error in the transmission data steadily or regularly, for example, external noise from the motor existing around the transmission line, or poor contact between the transmission line and the device, this cause However, there is a problem that the transmission quality becomes unstable because it is left unattended.

Therefore, an object of the present invention is to provide a communication system capable of eliminating a cause of a transmission error and always ensuring stable transmission quality by monitoring a transmission error occurring in the entire system. ..

[0006]

To achieve the above object, the present invention comprises a plurality of communication devices connected via a communication line, and a specific communication device among these communication devices serves as a master, and In the communication system in which the communication device is a slave, the communication device on the slave side detects the transmission error of the data transmitted from the communication device on the master side, and the transmission error is detected by this detection unit. In this case, the error occurrence information notifying means for generating the error occurrence information representing the occurrence status of the transmission error and transmitting the error occurrence information to the communication device on the master side. Further, the master side communication device is provided with an error occurrence information accumulating means for accumulating the error occurrence information sent from the slave side communication device.

Further, according to the present invention, as the communication device on the master side, error occurrence information accumulation means for accumulating error occurrence information sent from the communication device on the slave side, and transmission abnormality based on the information accumulated in this accumulation means It is also characterized in that it is provided with a transmission abnormality notifying means for notifying the occurrence of.

Further, according to the present invention, as the error occurrence information notifying means, when a transmission error is detected by the detecting means, the error occurrence information including information indicating the occurrence time and the number of occurrences of this transmission error is generated and the master is generated. It is also characterized in that it is transmitted to the communication device on the side.

[0009]

As a result, according to the present invention, the transmission error detected by the communication device on the slave side, which has been overlooked in the past, is
For example, the transmission error occurring in the entire system can be grasped by notifying the communication device on the master side as error occurrence information indicating the time and the number of occurrences of the transmission error. For this reason, it becomes easy to early find the cause that causes a transmission error steadily or regularly, such as an abnormality in the transmission path, and by doing so, eliminate the cause of the transmission error and always ensure stable transmission quality. You can

[0010]

EXAMPLE An example of the present invention will be described below. In the present invention, a private branch exchange system is taken as an example, and a case where the private branch exchange is used as a master communication device and the extension terminal is used as a slave communication device will be described.

FIG. 1 is a functional block diagram showing the configuration of a private branch exchange system according to an embodiment of the present invention. In the figure, this private branch exchange system comprises a digital private branch exchange (digital PBX) 1 and a plurality of digital telephones DP1 to DPn as extension terminals.

First, the digital telephones DP1 to DPn are
Main control circuit (CPU) 21, transmission control circuit 22, timer circuit 23, data terminal interface (I / F)
24 and a memory circuit 25. Transmission control circuit 2
Reference numeral 2 controls transmission of a communication signal transmitted / received to / from the PBX 1. The timer circuit 23 generates time information in response to the request of the CPU 21. Further, the data terminal interface 24 controls an interface with a data terminal (not shown).

The CPU 21 is provided with error occurrence information notifying means 21a in addition to various ordinary control means such as communication control during a call and during data transmission. This error occurrence information notifying means 21a checks whether or not a code error has occurred in the data coming from the PBX 1, and when a code error is detected, it generates error occurrence information indicating the detection time and, for example, the ISDN basic interface. The data is transmitted to the PBX1 using the D channel.

On the other hand, the digital PBX 1 has a switching circuit 11
, Central control circuit 12, storage circuit 13, timer circuit 14, ISDN terminal interface 15, ISDN
The local line interface 16 is provided. A maintenance terminal device 17 is connected to the central control circuit 12.

The ISDN terminal interface 15 performs a predetermined interface operation between the digital telephones DP1 to DPn and the switching circuit 11, respectively. Also ISD
The N station line interfaces 16 are IS (not shown), respectively.
A predetermined interface operation is performed between the DN network and the switching circuit 11. The above ISDN terminal interface 15
And the digital telephones DP1 to DPn use a basic interface in which two information (B) channels and one signal (D) channel are time-division multiplexed.

The central control circuit 12 is provided with an error occurrence information storage control means 12a and an abnormality display control means 12b in addition to a normal exchange connection control means such as call origination / termination control.
The error occurrence information storage control means 12a monitors arrival of error occurrence information from the digital telephones DP1 to DPn, and supplies this information to the storage circuit 13 for storage when the error occurrence information arrives. Further, the abnormality display control means 12b counts the number of occurrences based on the error occurrence information stored in the storage circuit 13, and when the cumulative total of the count values exceeds a certain value, the abnormality display is displayed on the maintenance terminal device 17, for example. It is something to do. Next, the operation of the communication system configured as above will be described.

FIG. 2 is a diagram showing a communication sequence when the transmission data "a", "b", "c", ... Are sequentially transferred from the PBX 1 to the digital telephone DP1, for example. An error detection code is added to each of these transmission data. CPU2 of digital telephone DP1 on the receiving side
First, in step 3a of FIG. 3, it is determined whether or not a code error has occurred in the transmission data "a" input via the transmission control circuit 22. As a result, when it is determined that the transmission data "a" has no code error, the CPU 21 transmits the transmission data "a" according to the predetermined processing routine in step 3b.
Process.

Next, the CPU 2 which has received the transmission data "b"
Similarly, 1 determines whether or not a code error has occurred in the transmission data "b" in step 3a. If the result of this determination is that there is a code error in the transmission data "b", the CPU 21 discards the transmission data "b" in step 3c and reads the current time from the timer circuit 23 in step 3d to generate an error. Generate information. Subsequently, in step 3e, it is determined whether or not the error occurrence information can be transmitted to the PBX 1, and if it is in the transmission possible state, the error occurrence information is transmitted to the PBX 1 on the D channel in step 3f. If the signal cannot be immediately transmitted to the PBX 1 due to other signal processing or the like, the error occurrence information is supplied to the storage circuit 25 and temporarily stored in step 3g. After this, the CPU
21 reads the error occurrence information from the storage circuit 25 at the time when transmission becomes possible, and transmits it to the PBX 1.

On the other hand, the control circuit 12 of the PBX 1 monitors the arrival of error occurrence information from the digital telephones DP1 to DPn during data transmission, as shown in step 4a of FIG. Then, when the error occurrence information arrives from the digital telephone DP1, the error detection time notified by this error occurrence information is supplied to the storage circuit 13 for storage in step 4b, and at the same time, in the variable K held by itself in step 4c, "1""Add up and count up. This variable K represents the number of times a code error has occurred in the line from the PBX 1 to the digital telephone DP1.

As described above, the control circuit 12 counts the number of occurrences of code errors detected by the digital telephones DP1 to DPn, while monitoring in step 4d whether or not the cumulative value of the variable K exceeds a certain value. ing. If the cumulative value of the variable K exceeds a certain value, the control circuit 1
2 judges that an abnormality has occurred in the transmission system from the PBX 1 to the digital telephone DP1, and displays the abnormality to the outside in step 4e. This abnormality display is performed, for example, by the maintenance terminal device 17. Further, as shown in step 4f, the control circuit 12 also monitors whether or not the number of code errors occurring within a predetermined time exceeds a certain value. If the number of code errors exceeds a certain value, step 4e is performed as described above.
Is displayed to the outside to indicate that an abnormality has occurred.

As described above, according to the present embodiment, the code errors detected by the digital telephones DP1 to DPn are notified to the PBX 1 as error occurrence information, so that the code errors occurring in the system, especially from the PBX 1 are caused. Regular or steady monitoring of anomalies occurring on the transmission lines to the digital telephones DP1 to DPn is strengthened. For this reason, it becomes possible to reliably detect an abnormality in the downlink transmission line that could not be detected by the PBX 1 in the related art. As a result, for example, external noise that is regularly generated from the motors existing around the transmission line at the time of startup thereof, and the device It is possible to detect an abnormality in the data transmission line such as a steady transmission error caused by a poor contact between the transmission line and the transmission line in an early stage and reliably. As a result, it is possible to always ensure stable transmission quality in the system.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the error occurrence information sent from the digital telephones DP1 to DPn in the PBX 1 is supplied to the storage circuit 13 and stored therein. However, this may be stored in an external storage device or the like provided separately. You may. In the above embodiment, the PBX side displays that an abnormality has occurred in the transmission system from the PBX 1 to the digital telephone 1. However, if there is a request from the digital telephone side, it is displayed on the digital telephone side. It is also possible to In this case, the PBX 1 transmits the required information to the digital telephone via the transmission line.

In addition, in the method for detecting the abnormality of the transmission line based on the error occurrence information, the content of the error occurrence information and the type of extension terminal, and the applied communication system, etc.
Various modifications can be made without departing from the scope of the present invention.

[0024]

As described above in detail, according to the present invention, when a transmission error is detected in the communication device on the slave side, error occurrence information indicating that a transmission error has occurred in the received data is generated. By transmitting the error information to the master side communication device and storing this error occurrence information in the master side communication device, it is possible to reliably grasp abnormalities in the system, especially abnormalities in the downlink transmission line going from the master side to the slave side. As a result, it is possible to provide a communication system capable of accurately determining the cause of a transmission error and eliminating the cause.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of a private branch exchange system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a communication sequence when transferring data from the PBX side to the digital telephone side.

3 is a flowchart showing a control procedure and control contents of a CPU of the digital telephone shown in FIG.

4 is a flowchart showing a control procedure and control contents of a central control circuit of the digital PBX shown in FIG.

[Explanation of symbols]

1 ... Digital private branch exchange (digital PBX), 11
... exchange circuit, 12 ... central control circuit, 12a ... error occurrence information storage control means, 12b ... abnormal display control means, 13 ... storage circuit, 14 ... timer circuit, 15 ... ISDN terminal interface, 16 ... ISDN office line interface, 17 …
Maintenance terminal devices, DP1 to DPn ... Digital telephones,
21 ... Main control circuit (CPU), 21a ... Error occurrence information notifying means, 22 ... Transmission control circuit, 23 ... Timer circuit, 24
... data terminal interface (I / F), 25 ... storage circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04Q 3/58 101 9076-5K

Claims (3)

[Claims] 1. A communication system comprising a plurality of communication devices connected via a communication line, wherein a specific communication device among these communication devices serves as a master and another communication device serves as a slave. The communication device includes detection means for detecting a transmission error of data transmitted from the master-side communication device, and error generation information indicating the occurrence status of the transmission error when the transmission error is detected by the detection means. And an error occurrence information notification unit for transmitting the error occurrence information to the master side communication device, and the master side communication device stores the error occurrence information sent from the slave side communication device. And an error occurrence information storage means. 2. The communication device on the master side stores error occurrence information accumulating means for accumulating error occurrence information sent from the communication device on the slave side, and occurrence of a transmission error based on the information accumulated in this accumulating means. The communication system according to claim 1, further comprising: a transmission abnormality notifying unit that notifies 3. The error occurrence information notifying means, when the transmission error is detected by the detecting means, generates error occurrence information including information indicating the occurrence time and the number of occurrences of this transmission error, and the master side communication device. The communication system according to claim 1 or 2, wherein the communication system transmits the