JPH03266545A - Elimination system for noise sound due to voice data error in inside of lan - Google Patents

Abstract

PURPOSE:To prevent noise sound from being sent to a voice terminal equipment by outputting a correct data just before occurrence of an error from an interface board in place of an erroneous data. CONSTITUTION:A parity check device 13 checks the presence of an error as to a digital data sent from a node inside 11 at a predetermined period through a digital data transmission line 12 and the result is informed to a control circuit 15 through a parity error signal line 14. The control circuit 15 based on the result outputs a control signal 16 to a transmission changeover circuit 18 and a buffer 17. When an error takes place, the transmission changeover circuit 18 aborts the error data and outputs a just preceding data from the buffer 17 to a D/A converter 19 and the voice analog signal 20 is sent to a voice terminal equipment 23. Thus, output of a noise sound is prevented to the voice terminal equipment 23.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to LAN (Local Area Network),
In particular, it relates to a LAN capable of transmitting audio data.

[Prior Art] In a LAN, a commonly used method for detecting audio data errors is to add a data error detection code to data obtained by converting an audio analog signal into a digital signal, and then add a data error detection code to data that is converted from an audio analog signal to a digital signal, and to detect whether the data is transmitted on the LAN or not. In various places,
There is a method to prevent data errors by checking whether or not data errors have occurred, and if a data error occurs several times, that part is considered to have failed and is replaced.

[Problem to be solved by the invention] However, in the case of the conventional method, it is possible to prevent data with data errors from being transmitted to the interface board of the node; However, there is a problem in that the sound is transmitted to the audio terminal as an abnormal sound.

This abnormal sound can be extremely annoying in the case of a LAN used in a broadcasting facility or the like.

The object of the present invention is to eliminate the drawbacks of the prior art described above, and to
An object of the present invention is to provide an abnormal sound deletion method that prevents the generation of abnormal sounds due to data errors occurring in an AN by a simple means.

Means for Solving the Problem] The abnormal sound deletion method of the present invention converts audio analog signals sent from audio terminals connected to each node of the LAN into digital signals on the interface board of the node. A parity pit is added to the converted data, and after the data flows through the LAN and reaches the other party's interface board, a parity check is performed, and if a data error occurs, the previous data is sent to the terminal side. It is.

[Function] When an error occurs, the correct data immediately before that is output from the interface board in place of the data with the data error, so the audio terminal receives silent data instead of the abnormal sound caused by the data error. This will prevent the sound from being transmitted to the audio terminal as an abnormal sound.

[Example code] Embodiments of the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, a parity checker 13,
A buffer 17 for outputting the immediately preceding data to the audio terminal when a parity error occurs, and a transmission line switch 1
8 will be provided. Further, a D/A converter 19 and a parity inserter 22 are provided.

12 is a digital data transmission path.

The audio analog signal 20 from the audio terminal 23 connected to a node of the LAN is provided on the interface board 24 inside the node 11, or is converted into a digital signal by the 'A converter 19, and then converted to a digital signal by the parity inserter 22. A parity bit is added and sent to the LAN.

After flowing through the LAN and reaching the other party's interface board 24, a parity check is performed, and if a data error has occurred, the previous data is sent to the audio terminal 23 side and abnormal sounds are deleted.

That is, first, the parity checker 13 checks for errors in the digital data sent from the inside of the node 11 through the digital data transmission path 12 at a fixed cycle, and the result is sent to the control circuit 15 through the parity error signal line 14. Inform. The control circuit 15 outputs a control signal 16 to the transmission line switch 18 and buffer 17 based on the result.

If no error has occurred, the transmission line switch 18 outputs the data to the buffer 17 and the D/A converter 19, as shown in FIG. The D/A converter 19 converts this data into an audio analog signal 20 and outputs it to the audio terminal 23.

When an error occurs, as shown in FIG. 3, the transmission line switch 18 discards the error data, outputs the previous data from the buffer 17 to the D/A converter 19, and transmits the audio analog signal 20 to the audio terminal. 23 to output.

If the same data is continuously converted into an audio analog signal, there will be audio silence, so the audio terminal 23 will receive the silence.

[Effects of the Invention] As explained above, according to the present invention, even if an audio data error occurs within the LAN, abnormal sound will not be output to the audio terminal, and data errors will not occur for a long time. In this case, the audio output can be muted.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the configuration inside an interface port for implementing the present invention, Fig. 2 is a diagram showing the flow of data when no data error occurs, and Fig. 3 is a diagram showing a data flow when no data error occurs. FIG. 3 is a diagram showing the flow of data when this occurs. In the figure, 11 is inside the node, 12 is a digital data transmission line, 13 is a parity checker, 14 is a parity error signal, 15 is a control circuit, 16 is a control signal, 17 is a buffer, 18 is a transmission line switch, and 19 is a 20 is a D/A converter, 20 is an audio analog signal, 22 is a parity inserter, 23 is an audio terminal, and 24 is an interface board. 1st Figure 77: Notes Iji Ito 23,

Claims (1)

[Claims] 1. In a LAN, the audio analog signal sent from the audio terminal connected to each node of the LAN is converted into a digital signal on the node's interface board, and a parity bit is added to the data, and the data is transmitted within the LAN. After reaching the other side's interface board, a parity check is performed and if a data error has occurred,
A method for removing abnormal sounds caused by audio data errors inside a LAN, which is characterized by transmitting the immediately preceding data to the terminal side.