JP3439398B2 - Facsimile machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus which transmits an optimum training check signal.

[0002]

2. Description of the Related Art In a facsimile machine according to a conventional communication recommendation, after a training check signal (hereinafter referred to as a TCF signal) is transmitted from a transmitting side, when the receiving side cannot perform training by the TCF signal, A training failure signal (hereinafter referred to as FTT signal) is returned to the transmitting side to request retraining.
At this time, the transmission side does not know the cause of the training failure, and therefore attempts to avoid the training failure by reducing the communication speed of the TCF signal, but in some cases it cannot be avoided by itself.

As a method for avoiding the above problem, the reason why the training on the receiving side has failed is returned to the transmitting side as facsimile information field (hereinafter referred to as FIF) information in the FTT signal, and the transmitting side returns the returned FTT signal. A method of optimizing the TCF signal based on the FIF information and retransmitting it to the receiving side was examined. At this time, the receiving side adds the cause of the training failure to the FTT signal as facsimile information field (hereinafter referred to as FIF) information and returns it to the transmitting side. The transmitting side uses the FIF information in the returned FTT signal to indicate the TCF. Optimize the signal and retransmit it to the receiver.

When a method of adding the cause of such training failure to the FTT signal as FIF information and notifying the result is investigated, an example of using the FIF information of the FTT signal is disclosed in JP-A-62-123873. JP-A-02-009264 and JP-A-03-00174
There is an invention described in Japanese Patent No.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The inventions described in Japanese Patent No. 123873 and Japanese Patent Laid-Open No. 03-001742 both notify the error rate or error bit information at the time of receiving a TCF signal as FIF information of the FTT signal, and optimize the transmission speed of the TCF signal. It aims at avoiding errors on the line. However, even if avoiding the training failure by slowing down the transmission speed of the TCF signal has the effect of reducing the number of hole backs, it may not be possible depending on the line conditions.
The above method of changing the transmission rate has a limit in dealing with various causes of training failure and eliminating the error of TCF signal reception in all line situations. In the present invention, instead of changing the transmission rate from the error rate or the error bit information, the training failure is avoided from the reception level of the TCF signal and the continuous time in which there is no error.

Further, the invention described in Japanese Patent Application Laid-Open No. 02-009264 further reports AGC control voltage information and error bit information at the time of receiving a TCF signal as a CFR signal (reception preparation confirmation signal) and FIF information of an FTT signal. Then T
Although the aim is to avoid errors in TCF signal reception by optimizing the CF signal transmission speed and transmission level, it is considered to be insufficient for avoiding training failure, and in the present invention, similar to the above. By trying to avoid the training failure from the reception level of the TCF signal and the continuous time in which there is no error, the training is attempted more reliably.

An object of the present invention is to provide a facsimile apparatus capable of transmitting a TCF signal which is optimum for the line condition.

[0008]

The present invention provides training.
When there is no error while receiving the check signal
Between the training check signal analysis means for analyzing the reception status of the training check signal from between, and when the training fails, the analysis result information of the training check signal is added as facsimile information field information to give the training failure signal as the training check signal. Facsimile information field addition means for transmitting to the terminal that has sent the signal, training failure signal analysis means for analyzing the facsimile information field information if the received training failure signal is added to the received training failure signal, and said facsimile information field information Training check signal transmitting means for transmitting a training check signal optimally set according to the analysis result information to the terminal that has transmitted the training failure signal. And butterflies.

The present invention provides a training check signal (T
By adding the cause of the failure when receiving the CF signal) to the training failure signal (FTT signal) as the facsimile information field (FIF) information, the cause of the failure at the subsequent transmission of the TCF signal By transmitting the TCF signal in consideration of the line characteristics, it is possible to reduce the failure of training and shorten the communication time and improve the communication property.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a facsimile apparatus of the present invention. The facsimile machine shown in FIG. 1 operates under program control. It should be noted that this program control is valid only when communication is made between the facsimile devices that have been individually agreed. This facsimile apparatus includes a TCF reception analysis circuit 1, a TCF transmission control circuit 2, a protocol control circuit 3 and an FTT signal FI.
An F information adding circuit 4 and an FTT signal analyzing circuit 5 with FIF information are provided.

The TCF reception analysis circuit 1 receives the TCF signal, the reception level when the TCF signal is received, the error status of the TCF signal,
The analysis result information is determined based on the time when no error occurred during the reception of the CF signal (the time or the number of times the data of 0 was continuously received) or the like.

The TCF transmission control circuit 2 uses the FTT signal F
The optimum TCF signal is set from the IF information.

The protocol control circuit 3 controls transmission / reception of signals according to the ITU-T recommendation.

The FTT signal FIF information adding circuit 4 uses the FT
The analysis result information at the time of receiving the TCF signal is added to the T signal as FIF information.

The FTT signal analysis circuit 5 with FIF information is
If FIF information is added to the received FTT signal, that information is analyzed.

Next, the overall operation of this embodiment will be described in detail with reference to FIGS. 1 and 2. Figure 2
FIG. 6 is a diagram showing an example of a signal procedure when reception of a TCF signal fails.

The first TCF signal in FIG. 2 is sent from the transmitting terminal to the receiving terminal with the default setting value of the device. When the receiving terminal receives the TCF signal, the TCF reception analysis circuit 1 of FIG. 1 analyzes the reception state of the TCF signal, and if the training fails, the analysis result is sent to the FTT signal via the protocol control circuit 3. The FIF information adding circuit 4 is notified. The FTT signal FIF information addition circuit 4 uses the FTT
The analysis result notified as FIF information is added to the signal, and the signal is transmitted from the receiving terminal to the transmitting terminal as the FTT signal with FIF information in FIG.

When the transmitting terminal receives the FTT signal with FIF information, the FTT signal with FIF information analyzing circuit 5 shown in FIG.
Analyzes the cause of the error in the TCF signal (the cause of failure in training), and notifies the TCF transmission control circuit 2 of the analysis result via the protocol control circuit 3. TCF
In order to avoid the cause of the error, the transmission control circuit 2 changes the signal transmission level, the signal transmission timing, the signal length, etc., and transmits it as the retransmission TCF signal of FIG. 2 from the transmission terminal to the reception terminal.

FIG. 3 is a diagram showing an example in which the contents of the FTT signal with FIF information are defined. The Facsimile Control Field (FCF) has F defined in the ITU-T recommendation.
The value of TT is entered. Facsimile information field (FI
Since F) is not defined by the ITU-T recommendation, the reason why the TCF signal reception fails is exchanged by exchanging a value determined independently between the facsimile devices.

In FIG. 3, in the facsimile information field (FIF), as a data section definition when the length is 1 byte, for example, 0x01 is insufficient reception level, 0
x02 is 0, the maximum continuous time is 600 msec or less, 0
x03 defines that the maximum continuous time of 0 is 800 msec or less.

Although FIG. 3 shows an example of the notification of the result when the length is 1 byte, the length can be extended to 2 bytes or more, and more detailed contents can be notified.

Next, another embodiment of the present invention will be described.

In FIG. 2, a signal different from the conventional one is FI.
It is a parameter of the FTT signal with F information and the TCF signal at the time of retransmission. Although an example of the definition has been described with reference to FIG. 3, NSF signals (non-standard function identification signals) and NSC signals (non-standard functions) used only between facsimile machines that have been individually agreed to eliminate troubles with conventional apparatuses. In addition to the non-standard signals such as the function command signal) and the NSS signal (non-standard function setting signal), by adding the definition for notifying the receiving ability of the FTT signal with FIF information and the specification of the format, the other embodiment can be realized. , Functional enhancement can be facilitated by ensuring the extensibility of future data.

FIG. 4 is a diagram showing a protocol of another embodiment. The NSF signal is notified by designating the ability of the receiving terminal to output the FTT signal with the FIF information and the FIF format. The NSS signal responding to this is realized by the transmitting terminal also being able to receive the FTT signal with the FIF information, and by deciding and notifying the FIF format.

[0026]

As described above, according to the present invention, the cause of the error at the time of receiving the training check signal (TCF signal) is analyzed on the receiving terminal side and notified to the transmitting terminal side. The optimal training check signal can be transmitted to the device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a facsimile apparatus of the present invention.

FIG. 2 is a diagram showing an example of a signaling procedure in which reception of a TCF signal has failed.

FIG. 3 is a diagram showing an example in which the contents of an FTT signal with FIF information are defined.

FIG. 4 is a diagram showing a protocol of another embodiment.

[Explanation of symbols]

1 TCF reception analysis circuit 2 TCF transmission control circuit 3 Protocol control circuit 4 FTT signal FIF information addition circuit 5 FTT signal analysis circuit with FIF information

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuhiro Ohama 1-403, Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa NEC Telecom Systems Co., Ltd. (56) Reference JP 62-123871 (JP, A) Special Kaihei 3-1742 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/32-1/34

Claims (6)

(57) [Claims] 1. An error occurs during reception of a training check signal.
Training check signal analysis means for analyzing the reception status of the training check signal from the continuous time in which no error occurred, and when training fails, the analysis result information of the training check signal is added as facsimile information field information for training. Facsimile information field addition means for transmitting a failure signal to the terminal that has sent the training check signal, and training failure signal analysis means for analyzing the facsimile information field information if the received training failure signal has facsimile information field information. And changing the transmission level, transmission timing, and length of the signal according to the analysis result information of the facsimile information field information,
A facsimile apparatus, comprising: a training check signal transmitting unit that transmits a training check signal that avoids a cause of failure to the terminal that has transmitted the training failure signal. 2. The facsimile apparatus according to claim 1, wherein the definition information of the facsimile information field is transmitted / received by a non-standard signal before transmitting / receiving the training check signal. 3. The facsimile apparatus according to claim 2, wherein the definition information includes transmission / reception capability information of a training failure signal added with facsimile information field information and / or format information of a facsimile information field. . 4. A training check signal on the receiving terminal side.
The training check signal reception status is analyzed from the continuous time during which no error occurred during the reception of the training check signal, and when the training check signal reception fails, the analysis result information is displayed in the training failure signal in the fax information field information. And transmits to the transmitting terminal side, the transmitting terminal side analyzes the training failure signal, and resends a training check signal that avoids the cause of failure by changing the signal transmission level, transmission timing, and length. And a transmission control method for a facsimile machine. 5. The facsimile apparatus according to claim 4, wherein the definition information of the facsimile information field is transmitted / received by a non-standard signal before the training check signal is transmitted / received between the receiving terminal and the transmitting terminal. Transmission control method. 6. The facsimile apparatus according to claim 5, wherein the definition information includes transmission / reception capability information of a training failure signal added with facsimile information field information and / or format information of a facsimile information field. Transmission control method.