JPH02280549A - Signal transmitter - Google Patents

Abstract

PURPOSE:To surely detect a data error caused due to a fault of a transmission line or external noise or the like and to correct an erroneous data by applying time division multiplex to a start-stop bit data signal and a '1', '0' repetitive bit data signal in bit synchronization with the start-stop synchronizing bit data signal, and sending the result. CONSTITUTION:A transmission signal multiplex section 1 converts a start-stop synchronizing bit data signal (a) and a '1', '0' repetitive bit data signal (b) in bit synchronization with the start-stop synchronizing bit data signal into one signal by using the time division multiplex system and the resulting signal is sent to a receiver side via a transmission line. A reception signal demultiplex section 2 at a receiver side demultiplexes the multiplexed transmission signal into the start-stop synchronizing bit data signal (a) and the '1', '0' repetitive bit data signal (b) and sends them to an error detection/correction section 3. The error detection/correction section 3 confirms whether or not the said two signals have a prescribed format and when the start-stop synchronizing bit data signal (a) is in error, the irregular component of the repetitive bit data signal (b) is noticed by the error detection/correction section 3 to correct only a numeric data part of the start-stop synchronizing bit data signal (a).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in the field of data transmission, etc., in which data signals are transmitted to the other party via a transmission line (telephone line, optical fiber cable, etc.).

Prior Art The prior art will be briefly explained using the transmission format diagram shown in FIG.

In the figure, signal A indicates a format for transmitting a 7-bit code signal specified by the JIS standard or the like using the start-stop transmission method. Note that the code signal indicates the number "l". Signal B indicates a state in which the 7-bit code is erroneously changed due to disturbance noise or the like during transmission.

Normally, a transmission signal is sandwiched between a start bit and a stop bit, and a parity bit is added for data protection, and the transmission signal is transmitted in a format like signal A on a transmission path. However, the signal often changes due to some kind of abnormality in the transmission path or external noise. Then, the other party receives, for example, signal B.
(A signal with the number "7" is transmitted. The receiving side treats this erroneous signal as a normal signal. In other words, there is a parity pit (odd parity) added for data protection. However, there are still problems such as data errors.

Further, there are problems in that the method only detects the occurrence of an error, cannot correct the erroneous data, and requires means such as sending a request for retransmission to the transmitting side.

Problems to be Solved by the Invention The present invention solves the problems seen in conventional examples, reliably detects data errors caused by transmission path abnormalities, external noise, etc., and provides a method for correcting erroneous data. The purpose is to

Means for Solving the Problems The present invention provides time-division multiplexing of an asynchronous bit data signal supplied to one input and a bit data signal bit-synchronized with the asynchronous bit data signal supplied to the other input. a transmission signal multiplexing section that separates the multiplexed signal received via the transmission path into an asynchronous bit data signal and a repetitive bit data signal; The problem is solved by an error detection/correction section that checks the asynchronous bit data signal and the repetitive bit data signal.

The transmitting side time-division multiplexes the start-stop synchronization bit data signal and the repeating bit data signal of "1" and "0" which is bit-synchronized with the start-stop synchronization bit data signal and transmits the same. On the receiving side, after separating the asynchronous bit data signal and the repetitive bit data signal of "l" 0 which is bit synchronized with the asynchronous bit data signal, the receiving side performs a parity check of the asynchronous bit data signal as a first confirmation method. The second checking method is to check whether the repeated bit data signal is normally repeating "1" and "0" in synchronization with the asynchronous bit data signal. After the confirmation, the first confirmation result is referred to and the start/stop synchronization bit data signal at the position where the repeated abnormality occurs is corrected to solve the problem.

Embodiment Next, the concrete operation of the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows an airfoil embodiment of the invention.

In the figure, 1 is a transmission signal multiplexing unit which is bit-synchronized with the asynchronous bit data signal a input from the outside (computer, terminal equipment, etc.) and the asynchronous bit data signal.
A circuit that uses signal multiplexing (time division multiplexing, frequency multiplexing, etc.) to convert a repeated bit data signal of 1 "0" into a single signal and sends it to a transmission line. 2 is a received signal separation unit which extracts an asynchronous bit data signal a and a repeated bit data signal of "1" O in bit synchronization with the asynchronous bit data signal from one signal received via the transmission line. 3 is an error detection/correction unit that checks the contents of the received asynchronous bit data signal a and repeated bit data signal A, respectively, and checks for errors other than those in the predetermined format. A circuit for correcting an asynchronous bit data signal a in accordance with a predetermined format.

FIG. 2 shows an example of a signal transmission format and an example of error data correction of the present invention.

Next, the specific operation will be explained.

To simplify the explanation of the operation, normal signal transmission in which no failure occurs on the transmission path will be explained, and then a method for correcting signal errors that occur on the transmission path will be explained.

First, a transmission method for normal signal transmission and reception signals will be explained.

An asynchronous bit data signal a (for example, JIS 7
The bit character code (indicating the number “1” specified in the specification) and the repeating bit data signal “1” and “0” synchronized with the asynchronous bit data signal a are input (supplied) in the format shown in Figure 2. ) However, it is also conceivable that this repeated bit data signal is generated within the transmission signal multiplexing section 1 without being supplied from the outside.

Note that one of the features of the transmitting side of the present invention is that it transmits a repetitive bit data signal of "1" and "0" that is bit synchronized with the asynchronous bit data signal a.

The transmission signal multiplexing unit 1 converts the two synchronized signals into a single signal using a time division multiplexing method, a frequency multiplexing method, etc. Transmit to receiving side.

The received signal separation section 2 on the receiving side separates the multiplexed transmission signal into an asynchronous bit data signal a and a repetitive bit data signal S, and then sends them to the error detection/correction section 3.

As the separation method, a general method such as a time division separation method or a frequency separation method, which is opposite to the multiplexing method on the transmitting side, is used.

The error detection/correction section 3 detects the asynchronous bit data signal a.
It is confirmed whether the repeated bit data signal of "1"O" which is bit synchronized with the data signal is in a predetermined format.

One of the features of the receiving side of the present invention is a double correction function that can independently check the asynchronous bit data signal a and the repetitive bit data signal S and correct the data depending on the reception status of each.

For example, in the case of the asynchronous bit data signal a, the second
As shown in Figure A, confirm the data and parity bit. Since the parity bit is "1" (even parity) for the data "1" (1000110), it is determined that the data is normal.

Furthermore, in the case of the repeated bit data signal A, as shown in FIG. I judge that.

Therefore, there is no need to correct the received data.

Next, a method for correcting received data when an error occurs in received data due to a failure occurring in a transmission path or the like will be described.

Since the transmission signal multiplexing section 1 on the transmission side and the reception signal separation section 2 on the reception side are the same as those described above, they will be omitted here, and the operation of the error detection/correction section 3 will be mainly explained.

For example, the asynchronous bit data signal a is originally
A case where the data shown in FIG. A is incorrectly changed to the data shown in FIG. 2 C will be explained. The data in FIG. 2C shows that the number 3 (1100110) was received. , as it is, the data is normal, but if you pay attention to the parity bit of the next bit (even parity), “
1". That is, if the number 3 is normal, the PJ tipit must be "O", which means that the received data is found to be erroneous.

Furthermore, the repeated bit data signal should originally be data as shown in FIG. 2B, but it is incorrectly data (1000101010) as shown in FIG. In other words, it is an irregular format. Therefore, the error detection/correction section 3 pays attention to the irregular portion of the repetitive bit data signal a and corrects only the numeric data portion of the asynchronous bit data signal a. this,
As a result of the correction of the numerical part, the number 3 of the received asynchronous bit data signal a is corrected to the number 1 and is sent out as normal data.

Note that even if both the numerical part and the parity bit part of the received asynchronous bit data signal a are mistakenly determined to be normal data in the parity bit check, the repeated bit data signal cannot be checked. This is a double correction method that can correct erroneous data.

As is clear from the above explanation, with the conventional method, it was only possible to confirm the error that occurred on the transmission path, but with the present invention, a double error confirmation and correction method can be realized and the transmission quality is improved. can be significantly improved.

Effects of the Invention According to the present invention, double error detection and bit-by-bit correction of erroneous data generated on a transmission path can be performed with a simple configuration, so that reliable and high-quality data transmission can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a specific embodiment of the present invention, and FIG.
The figure shows a data correction method according to the present invention, and FIG. 3 is a diagram of a conventional transmission format. 1... Transmission signal multiplexing section, 2... Receiving signal separation section, 3... Error detection/correction section.

Claims (1)

[Claims] an asynchronous bit data signal provided to one input;
a transmission signal multiplexing section that time-division multiplexes the asynchronous bit data signal supplied to the other input with a bit synchronized bit data signal and sends it to a transmission path; A received signal separation unit that separates the bit data signal and the repeated bit data signal; and an error detection/correction unit that checks the asynchronous bit data signal and the repeated bit data signal separated by the received signal separation unit. A signal transmission device characterized by: