JPH05344105A - Error removing communication method - Google Patents

Abstract

PURPOSE:To easily apply a non-procedure fully duplex communication system to a center provided with an echo back and to eliminate the need for an exclusive hardware by regarding data subsequent to prompt as error and transmitting character erasing code as many as errors from a terminal to the center. CONSTITUTION:When any error data generated in a line during non- communication time from prompt transmission to the data transmission of a terminal T are present, the error data are counted by an error buffer T-2 since the data from the terminal T are echo-backed and transmitted to the terminal by the center C. For example, (n) pieces of error data generated in an incoming line L-2 are received and stored at a reception processing part C-2, and those data are echo-backed through a transmission processing part C-1 to the terminal T. At the time of transmitting the data from the terminal T, the error data are counted by the buffer T-2 and a character erasing code generation part T-3, and the (n) pieces of data attached the character erasing codes at the heads are transmitted. The center C processes the received data by erasing characters with the processing part C-2 while regarding them as invalid data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an error elimination communication method, and in particular, for transmitting a message or receiving information in a center between a center and a terminal device by a non-procedure full-duplex communication method. The present invention relates to an error elimination communication method applied to.

[0002]

2. Description of the Related Art A non-procedure full-duplex communication system is widely used mainly for personal computer communication between a center and a terminal and a network and a terminal. In this non-procedure full-duplex communication system, the center receives the data from the terminal and at the same time sends it back to the terminal as an echo back, and does not echo the data from the center to the center.

Conventionally, in this communication system, as an error elimination communication system, a system of checking whether an error has occurred due to a problem of line quality and retransmitting correct data is used.
Among them, in personal computer communication, FCS
(Frame Check Sequence) An error correction method or a parity check method is used.

FIG. 9 is a diagram showing an example of the FCS error correction method. In the figure, in the FCS error correction method, when the personal computers 91 and 94 communicate with each other, the data sent from the personal computer 91 is transferred to the modem 9
In step 2, the data is processed into a predetermined format (frame), and at that time, data for detecting an error is added and sent to the modem 93.
When the modem 93 receives the data, it checks whether or not there is an error, and if there is an error, issues a "retransmission request" of the data to the modem 92. The modem 92 receives this and retransmits it.

FIG. 10 is a diagram showing an example of the parity check method. In the figure, the parity check method is
When communicating with the personal computers 91 and 94,
The sending personal computer 91 adds a parity bit to the data and sends it to the personal computer 94. The personal computer 94 checks the parity of the received data. If there is an error, the two parties resend according to a predetermined procedure.

[0006]

However, the conventional FCS error correction system described above has the following problems. -The modem cannot be used unless both the center and terminal modems support the FCS error correction method. -Dedicated hardware such as a modem that supports the FCS method is required, and the processing required for setting for checking is complicated. -Even if no error occurs, extra data for error detection must be sent every time.

Further, the conventional parity check method has the following problems. -In general, 1 bit is assigned to the parity bit, so the data length is 7 bits, which is not suitable for exchanging 2-byte character codes such as kanji. -In the case of the non-procedure full-duplex communication method even if a data error is found, there is a problem that it cannot be retransmitted, and it is not used in general personal computer communication.

The present invention has been made in view of the above points, and in the full-duplex communication system, it does not use dedicated hardware when performing data communication, and is also used for general personal computer communication. It is an object of the present invention to provide an error-removing communication method that can achieve the above, and can easily and effectively realize communication error removal.

[0009]

The present invention provides a full-duplex communication method between a first communication device and a second communication device, comprising:
When the communication device receives the data from the second communication device, the data is echoed back to the second communication device, and when the character deletion code is received from the second communication device, the previously received character code is Cancel and notify the second communication device that the first communication device has entered the reception state as a prompt character string, and the prompt character string before the second communication device transmits data to the first communication device. The character deletion codes for the number of received data are transmitted to the first communication device after the reception of.

The present invention also counts unused character codes in the data received by the second communication device from the first communication device, and counts the unused character codes before transmitting the data to the first communication device. Send the character deletion codes for the character deletion codes for the number of used character codes.

[0011]

According to the present invention, first, an error occurring on a communication line is regarded as data after a prompt (input instruction character string from the center) is regarded as an error, and the error is removed. This method uses the fact that the noise generated during the non-communication time from the reception of the prompt to the transmission of the terminal is echoed back at the center and received at the terminal, and the data after the prompt is regarded as an error,
This is a method for eliminating errors at the center by transmitting character deletion codes for the number of error data from the terminal to the center. With this, when the non-communication time after the prompt is long, it is effective because the probability that an error occurs in this time zone is high, and when there is an error, the first communication device needs to request retransmission of data. There is no.

Secondly, the present invention monitors the data of the first communication device and detects an unused code to eliminate an error. This method is a method of determining an unused code in the data received from the first communication device as an error and removing the error. As a result, in the non-procedure full-duplex communication method, the setting of unused codes and the error characteristics are focused, and if the code extension method of JIS is used, it can be applied to personal computer communication using Chinese characters.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a flowchart of an error removing method according to a first embodiment of the present invention. 2 is a diagram showing the configuration of the first embodiment of the present invention.

The system of the full-duplex communication method in FIG. 2 is assumed to be composed of a center C, a telephone network N, and a terminal T. The center C receives the transmission data and performs a transmission process from the center C to the terminal T via the telephone network N, and a transmission processing unit C-1 that receives the data from the terminal T and echoes the data. To the transmission processing unit C-1.

The terminal T includes a console 10 and a keyboard 1.
1. Prompt detection unit T-1 for detecting a prompt which is an input instruction character string from center C, and prompt detection unit T
The data received after the prompt detected by -1 is input, and the data is input via the error buffer T-2 and the prompt detection unit T-1 which are accumulated, and the output processing unit T- for outputting the data to the console 10. 6, keyboard 1
The input processing unit T-4 that accumulates the information input from 1 as transmission data, and the error data in the error buffer T-2 is counted by the transmission trigger input from the keyboard 11, and the number of counted error data is n. The character deletion code generation unit T-3 that generates the minute character deletion code and the transmission unit T-5 that transmits the character deletion code generated by the character deletion code generation unit T-3 to the center C.

Next, the procedure of the terminal T processed by the system of FIG. 2 will be described with reference to the flowchart of FIG.

Step 101: After the center C and the terminal T are connected, a prompt character string for requesting an input instruction (passing the data transmission right from the center C to the terminal side) is added together with the data from the center C. To send. Terminal T
Waits until the data is received from the center C, and when it receives the data, shifts to the next step.

Step 102: The terminal T receives the data from the center C and performs a data receiving process.

Step 103: The prompt detection unit T-1 of the terminal T determines whether or not the prompt character string is added to the data. If the prompt character string is not added to the data, the process proceeds to step 101. .. Step 1 if the prompt character string is added to the data
Move to 04.

Step 104: It is judged whether or not the data after the prompt character string is received, and if there is data, the process proceeds to step 105.

Step 105: When the data following the prompt character string is received, the data is stored in the error buffer T-2 as error data.

Step 106: Wait until there is a trigger for transmission from the keyboard 11 (shown by the dotted line in FIG. 2).

Step 107: When there is a trigger from the keyboard 11, the character deletion code generator T-3 counts the error data in the error buffer T-2, and the character deletion code for the number n of the counted error data. To create.

Step 108: Character deletion code generator T
If the character deletion code <0 created in -3, the process proceeds to step 111.

Step 109: Character deletion code generator T
Of the n character deletion codes generated in -3.
Output to.

Step 110: Clear the count of the counted error data.

Step 111: Character deletion code generator T
The data from -3 is transmitted to the center C.

Next, a processing procedure between the terminals between the communication device A and the communication device B of this embodiment will be described. FIG. 3 shows a flowchart of processing between the communication devices according to the first embodiment of this invention.

Step 301: Communication device A sends data to communication device B.

Step 302: Communication device B receives data from communication device A.

Step 303: Communication device A sends a prompt character string to communication device B.

Step 304: Communication device B receives the prompt character string.

Step 305: Communication device B counts the received data after the prompt character string.

Step 306: In the communication device B, if the count of data after the prompt character string = 0,
Go to step 310.

Step 307: The communication apparatus B transmits the character deletion code for the counted data to the communication apparatus A and shifts to Step 310.

Step 308: Communication device A is communication device B
Receives data with a character deletion code at the beginning.

Step 309: The communication device A invalidates and removes the received data for the character deletion code.

Step 310: Communication device B sends data to communication device A.

Step 311: Communication device A is communication device B
Receives data from.

Step 312: Communication device A echoes back the received data to communication device B.

Step 313: Communication device B is communication device A
Receive echo back from.

Next, communication between the terminal T and the center C will be described. Since the center C sends the data sent from the terminal T side to the terminal as an echo back, after the prompt is sent, in the non-communication time until the terminal T sends the data,
If there is error data generated on the line, the error buffer T-
Counted by 2. For example, n pieces of error data generated in the uplink L-2 are received and accumulated in the reception processing unit C-2 of the center C, and at the same time echoed to the terminal T via the transmission processing unit C-1. Be backed.

When the terminal T transmits data, the error buffer T-2 and the character deletion code generator T-3 count the error data and transmit the data prefixed with n character deletion codes.

In the center C, the reception processing section C-2 invalidates and removes the received data corresponding to the character deletion code, so that only correct data excluding errors can be processed. Regarding the error that occurs in the downlink L-1, the center C will receive an extra character deletion code, but since there is no transmission data before the character deletion code, no adverse effect on communication will occur.

As described above, in the case of the terminal processing in which the input editing processing is performed by the terminal T and the data is collectively transmitted, the non-communication time is very long as compared with the time when data is actually transmitted / received. Become. Therefore, according to this embodiment, most of the errors that have occurred on the line during the non-communication time can be relieved.

Next, a second embodiment of the present invention will be described. FIG. 4 shows the configuration of the second embodiment of the present invention. Figure 4
The same components as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. The configuration shown in FIG. 4 has the prompt detection T of FIG.
The unused code detector T-10 is used instead of -1, and the counter T-20 is used instead of the error buffer T-2.
Is provided. The unused code detector T-10 checks whether the received data includes an unused code. The counter T-2 is an unused code detector T-1.
Increment when 0 detects an unused code.

FIG. 5 shows a flowchart of the error removing method according to the second embodiment of the present invention. Next, the processing procedure of the terminal device will be described based on the configuration of FIG. 4 together with the flowchart of FIG. Step 401: After the terminal T is connected to the center C,
The process waits until data is received from the center C, and if it is received, the process proceeds to the next step.

Step 402: The terminal T receives the data from the center C and performs a data receiving process.

Step 403: The unused code detector T-10 of the terminal T judges whether the data contains an unused code. If the data contains an unused code, the process proceeds to step 404. ..

Step 404: In step 403, if the unused code is included in the data, the counter T-20 is incremented.

Step 405: When the transmission trigger is received from the keyboard 11, the character deletion code generation unit T-3 creates the character deletion codes for the number n of the unused codes counted in step 404.

Step 406: Character deletion code generator T
If the count of the character deletion code created in -3 ≦ 0, the process proceeds to step 409.

Step 407: The n character deletion codes generated by the character deletion code generation section T-3 by transmission are output to the transmission section T-5.

Step 408: The counter T-20 clears the counter value.

Step 409: The transmitter T-5 transmits the character deletion code created by the character deletion code generator T-3 to the center C.

As described above, since the unused code is checked even when the terminal receives the data from the center C, in addition to the case of the first embodiment, the center C transmits to the terminal T. It is also possible to remove noise generated on the uplink L-2 during the time when data is being transmitted. In this case, an error such as line noise cannot be detected unless it is an unused code. Therefore, the ability of error elimination depends on the unused code settings and the error characteristics.

FIG. 6 is a JIS8 unit code table. From the JIS8 unit code table of FIG. 6, character codes E0 to FE are undefined, and if the character deletion code is BS (character code 08) instead of DEL (character code FF),
The unused code can be changed from E0 to FF.

Also, for Kanji characters represented by 2 bytes, not JIS JIS code shift code, JIS X0202
By using the code according to the sign extension method, the character codes E0 to FF can be made unused.

As the error characteristic, the impulsive noise generated in the telephone line is a problem, and most errors are closed within the range of one modulation from this noise. FIG. 7 is a diagram for explaining a line error. The figure (A) shows the noise waveform generated during the non-communication time, the figure (B) shows error data, and the figure (C) shows an example treated as a character code.

As shown in the figure, when noise such as shown in (A) occurs in the line during the non-communication time, error data shown in (B) occurs and the character code F6 "0011111" is generated.
1 ”. Since the lower bits are modulated and transmitted in this way, most errors that occur during non-communication are from the character codes E0 to FF indicated by the hatched lines in FIG.

Next, communication device A and communication device B of this embodiment
The processing procedure between the terminals will be described. FIG. 8 shows a flowchart of processing between communication devices according to the second embodiment of the present invention.

Step 801: Communication device A transmits data to communication device B.

Step 802: The communication device B receives the data from the communication device A.

Step 803: Communication device B is communication device A
Detect unused code in data from.

Step 804: Communication device B is communication device A
Count the unused codes in the data.

Step 805: If the unused code count n ≦ 0, the communication device B moves to step 809.

Step 806: In the communication device B, if the unused code count n> 0, the character deletion codes corresponding to the counted unused codes are transmitted to the communication device A, and the process proceeds to step 809.

Step 807: Communication device A receives the character deletion code from communication device B.

Step 808: The communication device A performs processing for invalidating and removing the received data corresponding to the character deletion code, and proceeds to step 810.

Step 809: The communication device B transmits the data to the communication device A, and proceeds to step 812.

Step 810: Communication device A is communication device B
Receives data from.

Step 811: The communication device A echoes back the received data to the communication device B.

Step 812: Communication device B is communication device A
Receive echo back from.

As described above, according to the present embodiment based on the error characteristic, an error such as line noise can be efficiently removed, and an unused code can be used for the Chinese character represented by 2 bytes. It can also be applied to the exchange of character codes.

[0075]

As described above, according to the present invention, the non-procedure full-duplex communication method used in general personal computer communication can be widely applied when transmitting / receiving data. Further, the present invention can be easily applied to a center having an echo back and does not require dedicated hardware. Further, when there is no error, it is not necessary to send extra information, which is very efficient. In particular, it is particularly effective when applied to a terminal that performs input / edit processing at the terminal and transmits data collectively.

[Brief description of drawings]

FIG. 1 is a flowchart (terminal side processing) of an error removing method according to a first embodiment of this invention.

FIG. 2 is a configuration diagram of a first embodiment of the present invention.

FIG. 3 is a flowchart of processing between communication devices according to the first embodiment of this invention.

FIG. 4 is a configuration diagram of a second embodiment of the present invention.

FIG. 5 is a flowchart (terminal side processing) of the error removing method according to the second embodiment of this invention.

FIG. 6 is a JIS8 unit code table.

FIG. 7 is an explanatory diagram of a line error.

FIG. 8 is a flowchart of processing between communication devices according to the second embodiment of this invention.

FIG. 9 is a diagram showing an example of an FCS error correction method.

FIG. 10 is a diagram illustrating an example of a parity check.

[Explanation of symbols]

 10 console 11 keyboard 91 personal computer A 92 modem A 93 modem B 94 personal computer BC center N telephone network T terminal T-1 prompt detection unit T-2 error buffer T-3 character deletion code generation unit T-3 T-4 Input processing section T-6 Output processing section T-10 Unused code detection section T-20 Counter C-1 Transmission processing section C-2 Reception processing section L-1 Downlink L-2 Uplink

Claims (2)

[Claims] 1. A method of full-duplex communication between a first communication device and a second communication device, wherein when the first communication device receives data from the second communication device, the data is transmitted to the second communication device. When echoing back to the second communication device and receiving the character deletion code from the second communication device,
The previously received character code is canceled, the second communication device is notified as a prompt character string that the first communication device is in the reception state, and the second communication device transmits the data to the first communication device. An error-removing communication method, comprising transmitting character deletion codes for the number of data received after receiving the prompt character string to the first communication device before transmitting to the communication device. 2. The unused character code in the data received by the second communication device from the first communication device is counted, and the unused character code is counted before transmitting the data to the first communication device. 2. The error removing communication method according to claim 1, wherein character deletion codes of the character deletion codes for the number of character codes are transmitted.