JPH01130667A - Transmission control method for facsimile signal - Google Patents

Abstract

PURPOSE:To continue a communication without disconnecting a line by standing a receiving side by in a predetermined receiving mode state if a training fails and transmitting a signal requesting for the retransmission of a training signal when a succeeding control signal is detected. CONSTITUTION:If the training fails, the receiving side is stood by in the predetermined receiving mode state and if the succeeding control signal (for instance, MPS signal) fed from a transmitting side is detected, the signal (for instance, PTN signal) requesting for the retransmission of the training signal is transmitted to the transmitting side to train again and continue a control procedure thereafter. Thereby, even when the training by a training picture signal immediately before a picture signal fails, the communication can be continued without disconnecting the line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile signal transmission control method.

(Prior Art) As is well known, in a facsimile machine, when transmitting a facsimile image signal (hereinafter abbreviated as image signal) from the sending side to the receiving side, a training signal is sent to adjust the high-speed modem on the receiving side (FFI side). After training the high-speed modem on the receiving side, the control procedure of transmitting 〇 on the rain is executed at page qi of the image signal.

FIG. 4 is a sequence diagram showing a general transmission control procedure, in which a call signal of 1100H2 (CNG signal M
) to the receiver, the receiver transmits the called terminal identification signal (
After replying the CED signal, the non-standard function identification Shintan (NS
F signal B), a called terminal identification signal (C8I@ number), and a digital identification signal (DIS signal) are sequentially transmitted.

On the other hand, the transmitting side transmits a digital command signal Pi (DO8 signal) and then transmits a training signal (TRN Shintan) to train (phase adjustment) the high-speed model 1- on the receiving 4H side. After this, the sending side sends a training check ΔB (TCF signal), and the receiving side high-speed modem!・Check to see if it has been raced.

When the receiving side completes training, it returns a ready-to-receive signal (CFR signal) and confirms the ability (CFR signal) specified by the sending side.
For example, it is notified that the image signal can be received at the transmission speed).

Therefore, the transmitting side moves to transmitting the image signal of the first page, but before that, it transmits the training signal (TRN signal) again. Then, once the transmission of the image signal for the first page is completed,
Marge Page Shin F! i (MPS signal) to inform the receiving side that transmission of image signals for one page has been completed.

In response to this MPS signal, the receiving side sends a message confirmation signal (MCF signal) indicating that both signals have been completely received.
Reply. When the transmitting side receives the MCF Shintan, it transmits the training signal again to transmit the image signal for the second page, and then transmits the image signal for the second page. Thereafter, signals are transmitted and received in the same procedure as for the first page.

In such a control procedure, if training using the TRN signal at fuse B, which is transmitted immediately after DC8 Shintan, fails, a training failure signal (FT King signal) is sent from the receiving side to the transmitting side instead of CFR@tan. By sending
The procedure starting from the DO3 signal is executed again and TRNF5
Pi is retransmitted. In addition, after receiving both signals on page 6, if it is necessary to retrain the receiving high-speed modem, use 91-Lening Xiaodingshindan (RT) instead of the MCF signal.
P(l)t training negative signal (RTN Shintan)
By sending D OS (ae) to the sender, the receiver high-speed modem can be retrained by executing the procedure starting with DOS (ae).

[Problem that the invention seeks to solve]

However, if the training of the high-speed modem on the receiving side fails due to noise, etc., being transmitted to TR1 which is sent just before both signals on page 6, the receiving side cannot detect both signals themselves, so for example, CCITT According to the control procedure specified in Request T, 30, a transition is made to a control waiting state in a low-speed reception mode of 300 BPS. Then, when this control W Shintan waiting state exceeds the timeout time T2 (6±1 seconds), the process moves to a line disconnection procedure.

Therefore, when a noisy line such as an international facsimile line is used, a problem arises in that the line once connected is disconnected midway due to noise etc., and the connection operation has to be repeated many times.

The purpose of this light is to disconnect the line even if training using the training image signal immediately before the image signal fails.
An object of the present invention is to provide a transmission control method for facsimile B that allows communication to be continued without any interruption.

[Steps F to solve and cover problem J]

In Honkomei, if the training fails, the receiver is kept on standby in a predetermined reception mode state, and if a subsequent control signal sent from the transmitter (for example, MPS Shintan) is detected, the transmitter The configuration is such that a signal (for example, an RTN signal) requesting retransmission of a training signal is transmitted, retraining is performed, and subsequent control procedures are continued.

Here, as a form of detecting a control signal when training fails, ■ Transition to a low-speed reception mode state of 300 BPS, maintain a low-speed reception state while the carrier continues, and then detect the subsequent control signal in this state. The first form of detection is: 2400 BPS even if training fails because the modem state may converge over time.

The second mode is to stay in a high-speed reception state such as 4800BPS and detect RTC Shintan (control tIIl return Shintan) in the image signal while the modem is converged, and the second method is to stay in a high-speed reception mode and prevent carrier disconnection. Detected, 300BPS
There is a third mode in which the control signal is shifted to a low-speed reception mode state and a subsequent control signal is detected.

(Operation) If the training fails, the receiver ends in a predetermined reception mode. If a subsequent, for example, MPS signal sent from the transmitting side is detected in this state, retraining is performed using a training signal sent from the transmitting side, and the subsequent control procedure is continued.

If training fails in this way, the device is placed on standby in a predetermined reception mode, and retraining is executed when a control signal from the transmitter is detected.
It is possible to continue receiving subsequent image signals without disconnecting the line. Therefore, if training fails when sending the image signal of the Nth page, it is only necessary to retransmit only the image signal of the Nth page.

[Embodiment] FIG. 1 is a sequence diagram of a transmission control procedure showing an embodiment of the present Bonmei.

In Figure 15, the transmitting side and the receiving side train the receiving side high-speed modem at fuse B, and from the receiving side
When the FR signal is returned to the transmitting side, the transmitting side
Then, the process moves to the transmission operation of the rain shower on the first page, but before that, a TRN message is transmitted. At this time, Uke (, ffi
fil If high-speed modem training fails, the receiving side determines this training failure and transfers the DC8 of fuse B.
Move from the high speed reception mode set in Shintan to the 3008PS low speed reception mode. By the way, in the conventional control procedure, CF
After the reply of R4ri, if the training fails, the line disconnection procedure is started after the timeout time 2 has elapsed, but in this example, the low-speed reception mode of 300 BPS is continued, and the Ml) after the image signal is sent. It is in a state where it is waiting for the S signal.

The transmitting side sequentially transmits the image signal and the MPS signal regardless of the success or failure of training on the receiving side. Therefore, the receiving side receives the MPSF3P that is sent after the training failure.
Detect i. Specifically, the preamble of the MPS signal is detected. If this preamble is detected, a retraining denial signal (RTN signal) is sent to the transmitting side, requesting that the high-speed modem on the receiving side be trained.

Then, the transmitting side moves to Fuse B, executes the control procedure starting from the DO8 signal again, and when the retraining of the receiving high-speed modem is completed by retransmitting TRN (i), the transmitting side displays the second page image. Move on to the signal transmission procedure.

Therefore, by simply retransmitting the image signal for which training has failed, subsequent image signals can be received without performing the line connection operation again.

FIG. 2 is a sequence diagram of a transmission control procedure showing another embodiment of the present invention.

In the figure, the procedure up to the reply from CFR Shintan is the same as in Figure 1, but when moving to the transmission operation of the image signal for the first page, the TRN Shintan immediately before the image signal for the first page If it is assumed that training has failed, the receiving side determines this training failure and detects carrier disconnection from the transmitting side while remaining in the high-speed reception mode. When this carrier disconnection is detected, it shifts to the low-speed reception mode state of 3008 PS, waits for the next MPS @ signal to be transmitted, and when it detects the preamble of the MPS signal, transmits the RTN signal to the transmitting side. , requesting retraining of the receiving high-speed modem.

Then, as in the case of FIG. 1, the control procedure starting with the DO8 Shintan signal is executed, and the process moves to the transmission procedure of the second page image (1ffi number).

Therefore, in this embodiment as well, by simply retransmitting only the image signal for which training has failed, subsequent image signals can be received without performing the line connection operation again.

In addition, career decline is ;l! ! Although it is detected in the fast reception mode, it may also be detected in the slow reception mode.

Furthermore, as shown in the sequence diagram of FIG. 3, for example, ff
When the training using the training signal TRN of the straight curve of the image signal on page 11 fails, the modem stays in the high-speed reception mode as in the case of Fig. 2, and when the modem detects convergence, the RTC signal in the image signal is It is also possible to detect the red, and then shift to the slow reception mode state, detect the Ml) S signal, and send the RTN 5) to the transmitting side to request retraining.

On the other hand, in each of the above examples, 1
It is necessary to retransmit the image signals for each page. but,
If a retransmission request signal is defined as a non-standard procedure control signal instead of the RTN Shintan, it is possible to automatically retransmit the image signal for one page for which training has failed.

However, in this case, it is necessary to arrange a memory capable of storing image signals for at least one page on the transmitting side.

〔Effect of the invention〕

As explained above, in the present invention, if training fails, the receiving side is kept on standby in a predetermined reception mode state, and if a subsequent control signal sent from the transmitting side is detected, the transmitting side The configuration is such that a signal requesting retransmission of the training signal 8 is transmitted, retraining is performed, and the subsequent 11tl1 procedure is continued.

Therefore, even if training fails due to noise mixed into the training signal immediately before both signals, it is possible to continue communication (a) without disconnecting the line.

[Brief explanation of the drawing]

FIG. 1 is a sequence diagram showing one embodiment of the present invention, FIG. 2 is a sequence diagram showing another embodiment of the present invention, FIG. 3 is a sequence diagram showing a third embodiment of the present invention, and FIG. The figure is a sequence diagram showing a conventional general transmission control procedure. DO8...Digital command signal, TRN...Training signal, CFR...Reception ready signal, MPS...
...Multi-bage signal, RT N... Retraining negative signal, RT P... Retraining positive @ bow. Figure 4

Claims (1)

[Claims] In a facsimile signal transmission control method in which a training signal is sent from a transmitting side to a receiving side to train a high-speed modem on the receiving side, transmission of a facsimile image signal is started, wherein the receiving side uses a high-speed modem. After the training, the success or failure of the training is determined. If the training is a failure, it waits in a predetermined reception mode state, and if a control signal following the image signal sent from the transmitting side is detected, the training signal is transmitted. and a facsimile signal transmission control method, characterized in that after transmitting a signal requesting retransmission of the image signal to the transmitting side, a predetermined transmission control procedure is continued.