JPS61242171A - Facsimile communication system - Google Patents

Abstract

PURPOSE:To improve accuracy of circuit error detection in accordance with a CCITT recommendation T-4 by calculating terminal codes every each page at both stations; sending and receiving sides, then deciding accuracy of these communications on the basis of checking results by the existence and size of differences between them. CONSTITUTION:When image information sending procedures are proceeded at a sending equipment side 31, terminal coding EOL numbers from a beginning to a terminal end of PIX are counted at a count circuit 35 by the command of a transmission control circuit 32. On the other hand, at a receiving equipment side 36, EOL numbers included in PIX coming from a sending equipment 31 are counted at a circuit 40 in accordance with a directive of a control circuit part 39 and are stored in a storage circuit 41. When PIX for a page is completed, EOL numbers information which are calculated by the count circuit 35 from the sending equipment 31 side are included in an instruction MPS after giving a message and then sent out to the receiving equipment 36. If a comparison is made in the control circuit 39 of the receiving equipment 36 between EOL numbers in MPS and that of the storage circuit 41, and there is no difference between two numbers, it is decided that no omissions of the EOL numbers are found out at all and then a normal control is kept on. If there is any difference between two numbers, an alarm is issued as an inconsistency of the EOL numbers.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to facsimile communication systems, particularly CCITT Recommendation T.
The present invention relates to a facsimile communication system according to , 4.

[Conventional technique]

Regarding the facsimile communication system, the International Telegraph and Telephone Confederation (CCITT) has issued various notifications so that it can be used internationally. and T-Series Recommendations, 1980) stipulates that line detection should be based on EOL.

FIG. 3 is a diagram showing the configuration of a conventional facsimile communication system in accordance with CCITT Recommendation T.4, in which the facsimile transmitter 11/, the transmitting side control circuit 12. It consists of an encoder 13 and a transmitter modem 14.

The facsimile receiver 15 includes a receiving side modulator/demodulator 16° decoder 17. and a receiving side control circuit 18, and the two are connected by a line 19.

In the device shown in Fig. 3, as can be easily seen from its configuration, errors on the first line 19 appear on the screen as they are, and if there are too many errors, it becomes impossible to interpret the results.In order to avoid this, The line where the error occurred on the line 19 in the receiving side control circuit 18 (between EOL and EOLO)
Replace it with the previous normal line and record it on the screen to correct the screen length, and also count it as a line error, and if the number of 2-in errors in one page exceeds a certain level, it is assumed that it has not been received normally. Set the alarm.

The sending side also had a function to notify that fact.

FIG. 4 is a diagram showing the communication procedure from the start of the communication to the sending of an alarm, but the operation is easily understood from the operation of the system of the present invention, which will be explained later, so a description thereof will be omitted here.

Figure 5 is a diagram showing an example of a problem in the prior art, (a
) shows the image information PIX on the line, and (b) shows the reception screen, and 21 and 21a are normal, 22
and 22& indicate a case where there is an error in the line. 2
3 and 23& will be explained next.

[Problems to be solved by the invention]

The above is an explanation of the case where the problem 2- occurs on the line, and in that case there is no problem, but in reality, other problems may occur. In other words, in this conventional method, CCITT Recommendation T,4 itself is used for line detection.
Because it is based on office ladies.

As shown in 23 in Figure 5, the effect of line errors is EOL.
If it cannot be detected by the receiver's decoder,
The screen is shrunk as shown in 23a. And if EOL cannot be detected continuously.

Although the shrinkage of the screen increases, it does not increase as a line 2-, so there is a drawback that an alarm does not occur.

Furthermore, in communication systems for facsimile machines that do not comply with the CCITT recommendations, systems in which error detection is performed regardless of line by line have been adopted, but these systems are generally expensive and have problems in terms of mutual communication.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a facsimile communication system that complies with CCITT Recommendations T and 4 and can improve the accuracy of line fault detection.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an E.
The OL is counted on both the transmitting side and the receiving side, and it is determined whether communication is being performed normally based on the presence or absence or size of a difference in the counts.

That is, according to the present invention, one-stroke information is converted into a line termination code (E
In the communication method between the facsimile transmitter and the transmitter that encodes the data based on the OL (OL) and sends it to the line, the facsimile transmitter counts the EOL for each page during encoding, and the number of EOLs counted after the transmission of the image information is completed. Further, the facsimile receiver counts and stores the EOL number in the transmitted image information, and when the EOL number counted by the transmitting side is transmitted, the facsimile receiver counts and stores the EOL number in the transmitted image information. A facsimile communication system is obtained which is characterized by having means for determining whether or not communication is being performed normally by comparing the number of EOLs.

〔Example〕

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, in which a facsimile transmitter 31 includes a transmitting side control circuit 32. Encoder 33. In addition to the transmitting side modem circuit 34, a transmitting side EOL counter circuit 35 is provided, and the facsimile receiver 36 has a receiving side modem device 37. Decoder 38. In addition to the receiving side control circuit 39, a receiving side EOL count circuit and a storage circuit 41 are provided.

The receiving side control circuit 39 has a function of comparing the number of EOLs counted on the transmitting side and the number of EOLOs counted on the receiving side to determine whether there is a missing EOL.

FIG. 2 is a diagram showing the communication procedure in this embodiment.

In FIGS. 1 and 2, when the facsimile transmitter 31 enters the image information sending procedure, the transmitter side EOL count circuit 35 counts the number of EOLs from the beginning of the PIX to the end according to a command from the transmission control circuit 32. . On the other hand, on the side of the fa>simili receiver 36.

EO included in PIX from facsimile transmitter 31
The number of L is counted by the receiving side EOL count circuit 40 according to a command from the receiving side control circuit 39, and is stored in the storage circuit 41.

When the PIX for one page is completed, the facsimile transmitter 31 sends information on the number of EOLs counted by the transmitting side EOL count circuit 35 to the post-message command MPS (or EO
M or EOP) and send it to the facsimile receiver 36.

MPS (EoHop) on the facsimile receiver 36 side
The control circuit 39 compares the number of EOLs in the storage circuit 41 with the number of EOLs in the storage circuit 41, and if they match, it is determined that there was no missing EOL and the control goes to a normal state. If they do not match, an alarm is issued indicating that the EOL does not match. Note that in this example.

If they match, the MCF is sent to the facsimile transmitter 31.
If they do not match, an alarm is generated on the facsimile receiver 36 side, and at the same time, an RTN signal is sent to the facsimile transmitter 31.

As described above, for EOL, the transmitting modem 14
By realizing a means that can detect the influence of the circuit 2- of the line 42 including the receiving side modulation/demodulation circuit 16, it is possible to detect and notify the adverse effect on the screen that has been overlooked in the past. became possible.

In the above embodiment, the criterion is whether or not the number of EOLs on the sending side and the receiving side match.However, taking into account the redundancy of facsimile, it is important to consider the difference between the number of EOLs on the sending and receiving sides. The criterion for determination may be whether it is acceptable (how much undetected EOL is acceptable). Moreover, it goes without saying that there is no problem in combining it with conventional technology.

〔Effect of the invention〕

As can be seen from the above description, according to the present invention, even if EOL cannot be detected due to a two-line error in a facsimile communication system in which encoding and decoding are performed based on EOL, this can be detected. This makes it possible to improve the accuracy of single-line error detection.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the structure of a facsimile communication system according to an embodiment of the present invention, FIG. 2 is a diagram showing a communication procedure according to an embodiment of the present invention, and FIG. FIG. 4 is a block diagram showing an example of the configuration, FIG. 4 is a diagram showing a communication procedure in the prior art, and FIG. 5 is a diagram showing an example of a problem in the prior art.
(b) shows the image information on the line, and (b) shows the reception screen. Explanation of symbols: 31 is a facsimile transmitter, 32 is a transmission side control circuit, 33 is an encoder, 34 is a transmission side modulation/demodulation device, 3
5 is a transmitting side EOL counter circuit. 36 is a facsimile receiver, 37 is a receiving modem,
38 is a decoder, and 39 is a receiving side control circuit. 40 is a transmitting side EOL count circuit, and 41 is a storage circuit. 42 are respectively calling out the lines. L J Figure 5 (α) Cb”)

Claims (1)

[Claims] 1. Communication between a facsimile transmitter that encodes image information based on the end-of-line code (EOL) and sends it to the line, and a facsimile receiver that decodes the image information received from the line based on the EOL. In the method, the facsimile transmitter has means for counting the EOL for each page during encoding and transmitting the counted EOL number after the transmission of the image information is completed, and the facsimile receiver has a means for counting the EOL for each page when encoding, counting and storing the EOL in the image information, and when the EOL number counted on the sending side is sent, it is compared with the stored EOL number to determine whether communication is being performed normally. A facsimile communication method characterized by having a means for