JPH01274521A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To bring the reception of picture information into the best state by holding a coefficient of an equalizer if the line state is defective, inhibiting the training of a demodulator by a training sequence signal before picture information after a reception preparation confirming signal and restarting the training when the state is recovered. CONSTITUTION:If the training by a training sequence signal and a training check signal after 2nd and succeeding trials is failed, that is, a failure signal is outputted from a training failure signal transmission storage means 15 representing the output of a failure signal, the coefficient of the equalizer of a MODEM 6 is held and the training of the demodulator by the training sequence signal before the picture information after the reception preparation confirming signal is inhibited. If 1st training is successful and no signal representing the output of a failure signal from the means 15 exists, the holding of the coefficient of the equalizer and the inhibition of the demodulator training are not set. Thus, the event of disabled reception of picture information is evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a facsimile machine, and in particular,
It relates to facsimile machines that comply with CCITT Recommendations T.30 and T.4 (G3 standards).

(Prior Art) First, a binary code signal sequence of a G3 standard facsimile machine will be described.

Figure 5 shows CCITT Recommendation T. 3 shows a sequence of 30 binary-coded signals; FIG.

The names of each abbreviation shown in the figure are as follows.

CED: Called station identification signal DIS: Digital identification signal DCS: Digital command signal TRN: Training sequence signal TCF: }Learning check signal CFR: Reception preparation Wfi acknowledgment signal FTT: }Learning failure signal PIX: Image information (message) EOP: Procedure end signal MCF': Message confirmation signal DCN: Recessed line cutting command signal In Figure 5, after the receiver side replies DIS, the transmitter side sends DOS, TRN and TCP (first TRN and TCP) is output. This TRN equalizes the modem (modulator/demodulator) on the receiver side (determines the modem's equalizer coefficients), and TCP (continuous "0" signal for 1.5 seconds) ensures good equalization of the modem. It will be confirmed whether this has been done.

This first TRN and TCP output is performed at the maximum transmission speed of the facsimile device.

If this training is successful, the receiver outputs the CFR, and the transmitter outputs the TR again.
After N (TRN immediately before image information) is output, P
Transmission of IX is started.

In such a situation, the TRN after the CFR and before the picture information confirms the equalization (re-equalization) of the modem on the receiver side, and also ensures better convergence of the equalizer coefficients and improves the picture quality. Information reception status is further improved.

By the way, if training is not performed satisfactorily by the first TRN and TCP, FTT is output from the receiver side, as shown in FIG. after that,
From the transmitter side, again, DCS, TRN and TC
P (second TRN and TCP) is output.

The second TRN and TCP are performed at the same transmission rate as the first TRN and TCP, or at a slower transmission rate. If communication is performed at a slow transmission speed, the possibility of communication increases. The function of transmitting TRN and TCP at a slow transmission rate after training failure is called the automatic fall pack function.

If this second TRN and TCP reception is successful (that is, if the training is successful), the receiver side will output CFR, and if reception is still not successful, FTT will be output again. , further training will take place.

Now, if FTT is output from the receiver side, the line (
telephone lines) are often noisy and poor. In this case, even if training is successful using the TRN and TCP from the second time onward, noise may enter the TRN after the CFR (in other words, the TRN immediately before the PIX) and/or the PIX, causing the modem on the receiver side to There may be cases where re-equalization and convergence are not achieved (that is, there is divergence). In this case, even if PIX is sent from the transmitter side, the receiver side cannot receive it normally.

To prevent this problem, the equalizer coefficients are retained and C
A facsimile device has been proposed that is configured to prohibit TRN before image information after FR.

(Problems to be Solved by the Invention) As mentioned above, the TRN before the image information after the CFR confirms the equalization (re-equalization) of the modem on the receiver side and also checks the convergence of the equalizer coefficients. By training the TRN, PIX reception can be performed in the best condition on that line.

By the way, if the line is in good condition, it can be assumed that there is not much noise mixed into the communication information, so there is no possibility that the modem will not be able to re-equalize and converge during demodulator training using TRN before image information after CFR. rare.

However, in a facsimile machine configured to prohibit TRN before image information after CFR, even if the first training and TCP reception signal is good and CFR is output, that is, even if the line is good, The CFR
Training before image information is prohibited.

Therefore, in the conventional facsimile machine as described above, there is no fear that it will be impossible to receive image information.
If the line is good, training that does not need to be prohibited will be prohibited, and as a result, the reception of image information that should be possible in the best condition will no longer be possible. .

The present invention has been made to solve the above-mentioned problems.

(Means and effects for solving the problem) In order to solve the above problems, the present invention determines the communication line state,
The feature is that the equalizer coefficients of the modem are held after CFR transmission only when the line condition is poor, and training by TRN before image information after the CFR is prohibited.

As a result, when the line condition is good, training is performed using the TRN before image information after CFR, and it is possible to produce the effect of creating a stable demodulation state.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic block diagram of one embodiment of the present invention.

In FIG. 2, the reference numeral indicates an image information data bus, and the reference numeral C indicates a control bus.

A reading processing section 1 that reads image information from a document and a recording processing section 2 that records received image information are connected to a line memory control section 3.
It is connected to the.

The line memory control section 3 is connected to an information compression/decompression section 4, the information compression/decompression section 4 is connected to a communication control section 5, the communication control section 5 is connected to a modem 6, and the modem 6 is connected to a network control section 7. .

In this example, the modem 6 has a function of holding equalizer coefficients and a function of selecting training prohibition. Since the modem 6 having such a configuration is well known, its explanation will be omitted.

Further, the communication control section 5 has a microcombustion controller, and in addition to controlling data exchange between the normal modem 6 and the information compression/decompression section 4, it also controls the transmission and reception of data between the modem 6 and the information compression/decompression section 4, as will be described later with reference to FIG. CFR after first TRN and TCP reception
The function of the modem 6 described above to hold the equalizer coefficients depending on whether FTT is transmitted or FTT is transmitted;
The line memory control unit 3, the information compression/decompression unit 4, the communication control unit 5, the modem 6, and the network control unit 7 are connected to the main YG4S unit 9.
controlled by

The network control section 7 is connected to lines L1 and L2. Furthermore, a telephone 8 is connected to the network control section 7 as required.

FIG. 1 is a functional block diagram of an embodiment of the present invention. In this figure, the control section of the communication control section 5 that handles image information data is omitted because it is not directly related to the present invention.

In FIG. 1, a training state determining means 11 determines whether training has been successfully performed based on TRN and TCP sent from a transmitter. This determination signal is supplied to the CFR/FTT signal transmission determining means 12, the equalizer coefficient holding control signal generating means 13, and the training inhibiting control signal generating means 14.

The CFR/FTT signal transmission determining means 12 transmits CFR or FTT to the main control section 9 depending on the output signal of the training state determining means 11, that is, depending on whether the training has been performed satisfactorily. A command (control signal) to that effect is sent. Note that this CFR/FTT signal transmission determining means 12 receives an interrupt control signal from the main control section 9,
It is also possible to take in requests from the modem and decide to send CFR or FTT.

When the CFR/FTT signal transmission determining means 12 outputs a signal to the effect that FTT or FTT is to be transmitted, the FTT signal transmission storage means 15 stores this fact, and stores the signal to the effect that the CFR/FTT signal transmission determination means 12 outputs a signal indicating that FTT or FTT is to be transmitted. 13, and the training prohibition control signal generating means 14.

The training state determination means 11, the CFR/FTT signal transmission determination means 12, and the FTT signal transmission storage confirmation means 15 constitute a line state determination means 20.

The equalizer coefficient holding control signal generating means 13 generates an equalizer coefficient when the line condition determining means 20 determines that the line condition is not good, that is, when the training condition determining means 11 determines that the training has been performed satisfactorily. When a signal indicating that FTT has already been output from the FTT signal transmission storage means 15 is inputted, a control signal for causing the modem 6 to hold the equalizer coefficients is outputted.

Similarly, the training state prohibition control signal generating means 14 is also activated when the line state determining means 20 determines that the line state is not good, that is, when the training state determining means 11 determines that the training has been performed successfully. When the PTT signal sending storage means 15
If a signal indicating that FTT has already been output is input, a control signal is output to the modem 6 to prohibit training by TRN before image information.

As is clear from this Figure 1, TRN from the second time onwards
And if the training is successful by TCP, that is, if the FTT signal transmission storage means 15 outputs a signal indicating that FTT has been output, the equalizer coefficients of the modem 6 are held, and ' CF R Demodulator training by TRN before later image information is prohibited.

Further, if the training is successful by the first TRN and TCP, that is, if the signal indicating that FTT has been output is not output from the FTT signal sending storage means 15, the equalizer coefficients of the modem 6 are held; And prohibition of demodulator training by TRN before image information after CFR is not set.

Now, the equalizer coefficient holding control signal generating means 13 and the training prohibition control signal generating means 14 receive a determination signal indicating whether or not the training has been successfully performed from the training state determining means 11. However,
C output from the CFR/FTT signal transmission determining means 12
A signal indicating that the FR is to be sent may be supplied to the equalizer coefficient holding control signal generating means 13 and the training inhibiting control signal generating means 14.

FIG. 3 is a flowchart showing the operation of one embodiment of the present invention. This flowchart is for the sake of simplification.
The process is depicted as being executed after CHD and DIS are output from the receiver (that is, the facsimile machine).

First, in step S1, it is determined whether DC8 has been detected.

If DC8 is detected, the first TRN and TCP are received in step S2.

In step S3, it is determined based on the TRN and TCF whether the training has been performed satisfactorily.

If the training is successful the first time, a CFR is transmitted in step S9, and in step SIO,
TRN and PIX are received.

This TRN re-equalizes and converges the modem of the facsimile machine to provide the best possible PIX reception.

Then, in step 811, it is determined whether EOP has been detected.

If an EOP is detected, in step 812 the MCF
is transmitted, and after the DCN is received in step S13, the process ends.

In step S3, the first TRN and TC
If training has not been performed satisfactorily due to P, the process moves to step S4.

In step S4, the FTT is sent, and in step S5, the DCF and TRN and TCP
(2nd TRN and TCP) is received. Second
The TRN and TCP from the time onwards are the previous TRN and TCP.
The transmission rate is the same as that of the CP, or the transmission rate is slower than that of the TRN and TCP.

In step S6, it is determined by the TRN and TCF whether training has been performed satisfactorily.

If the training fails, return to step S4 again,
The third and subsequent training sessions will be held.

If the training is successful, the equalizer coefficient TAPS of the modem of the facsimile machine is retained in step S7, and subsequent demodulator training with the TRN before image information is prohibited in step S8. After that, the process moves to step S9 and subsequent steps. In this case, training is not performed even if the TRN is received in step SIO.

FIG. 4 is a functional block diagram of another embodiment of the present invention,
FIG. 2 is a diagram similar to FIG. 1; Further, in FIG. 4, the same reference numerals as in FIG. 1 refer to the same or equivalent parts, so a description thereof will be omitted.

As is clear from the comparison between FIG. 4 and FIG. 1, in this embodiment, training failure storage means 16 is provided in place of FTT signal transmission storage means 15.

This training failure storage means 16 stores a signal output from the training state determination means 11 indicating that the training has ended unsuccessfully. This signal is output to equalizer coefficient holding control signal generation means 13 and training state inhibition control signal generation means 14.

Also in the embodiment having the above configuration, as in the embodiment described above with reference to FIG.
When the training is successful by the CP, that is, when the training failure storage means 16 outputs a signal indicating that the training was unsuccessful, the equalizer coefficients of the modem 6 are held, and the CFR Later TR
Training by N is prohibited.

In addition, if the training is successful by the first TRN and TCP, that is, the training failure storage means 1
If the signal indicating that the training was unsuccessful is not outputted from 6, the equalizer coefficients of modem 6 are held;
And prohibition of training by TRN after CFR is not set.

In FIG. 4, the equalizer coefficient holding control signal generating means 13 and the training prohibition control signal generating means 14 receive a determination signal from the training state determining means 11 indicating whether or not the training has been successfully performed. Although shown as being input, the CFR signal or the signal indicating that CFR is to be sent is output from the CFR/FTT signal sending determining means 12 in the same manner as described above with respect to the embodiment shown in FIG. , the equalizer coefficient holding control signal generating means 13;
The signal may also be supplied to the training prohibition control signal generating means 14.

Now, in the above description, the line state determining means 20.
21 are both the training state determining means 11 and the CF
Although the explanation has been made assuming that the R/FTT signal transmission determination means 12 is provided, since the determination of whether the training is successful is connected to the determination of whether to transmit CFR or FTT, each of the above-mentioned There is no need to consider means 11 and 12 separately.

Furthermore, the equalizer coefficient retention control signal generation means 13 and the training prohibition control signal generation means 14 set retention of the equalizer coefficients and prohibition of training when the first training is not successful. It was explained as a thing.

However, the present invention is not particularly limited to this, and is configured to retain the equalizer coefficients and prohibit training if the second or Nth training is not successful. Of course, it is okay to do so.

The configuration in this case can be easily created by those skilled in the art, so its explanation will be omitted.

Furthermore, in the above description, the modem 6 was assumed to have the function of holding equalizer coefficients and the function of selecting training prohibition, but the present invention is not limited to this. Alternatively, a modem that does not have the function of holding equalizer coefficients and the function of selecting prohibition of training may be used, and each of the above functions may be set by the communication control unit 5 or the like. The configuration in this case can also be easily created by those skilled in the art, so its explanation will be omitted.

Furthermore, in the explanation regarding FIG. 2, the facsimile apparatus has been described as having the reading processing section 1, but the present invention relates to training on the image information receiving side, and image information reading and transmitting functions are particularly necessary. Not.

(Effects of the Invention) As is clear from the above description, according to the present invention, when the line condition is poor, equalizer coefficients are retained and demodulation by TRN before image information after CFR is performed. When equalizer training is prohibited and the line condition is good, equalizer coefficients are not held and demodulator training is performed using TRN before image information after CFR. This effect is achieved.

In other words, when the line condition is poor, the TRN after CFR and the image information prevent the modem from dissipating and making it impossible to receive the image information, and when the line condition is good, In this case, the equalizer coefficients of the modem can converge better, and the image information can be received in the best possible manner.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of an embodiment of the present invention. FIG. 2 is a schematic block diagram of one embodiment of the present invention. FIG. 3 is a flowchart showing the operation of one embodiment of the present invention. FIG. 4 is a functional block diagram of another embodiment of the present invention. Figure 5.6 shows a sequence of CCITT Recommendation T, 30 binary-coded signals. 5... Communication control unit, 6... Modem, 11... Training state determining means, 12... CFR/FTT signal sending determining means, 13... Equalizer coefficient holding control signal generating means, 14 ...Training prohibition control signal generating means,
15...FTT signal sending memory means, 16...Training failure memory means, 20.21...Dag line state determination means Representative patent attorney Michito Hiraki and 1 other person No. 3rIJ

Claims (4)

[Claims] (1) It has a modem that sets its equalizer coefficients through training, and has a modem that sets its equalizer coefficients by training, and complies with CCITT Recommendation T. A facsimile device that performs communication using 30 transmission procedure signals, the facsimile device comprising a line condition determining means for determining a communication line condition, and an equalizer coefficient for holding a modem equalizer coefficient according to the communication line condition. A facsimile apparatus comprising: a holding means; and a training prohibition means for prohibiting training according to a communication line condition. (2) The modem has an equalizer coefficient holding function that holds the equalizer coefficients and a training prohibition function that prohibits training, and the equalizer coefficient holding means has the equalizer coefficient holding function that holds the equalizer coefficients. Claim 1, characterized in that the equalizer coefficient holding control signal generation means activates the equalizer coefficient holding control signal, and the training prohibition means is a training prohibition control signal generation means that activates the training prohibition function. Facsimile machine as described. (3) The line state determining means includes training state determining means for determining a training state, and storage means for storing that training has failed at least once, or storage means for storing that training failure signal FTT has been sent out at least once. The equalizer coefficient holding means and the training inhibiting means are configured to send a signal indicating that the training has failed from one of the storage means when the training status determining means determines that the training has been successfully performed. Claims 1 or 2, characterized in that when a signal indicating that the failure signal FTT has been sent is output, the equalizer coefficients of the modem are held and training is prohibited. Facsimile machine as described. (4) The line state determining means includes a training state determining means for determining a training state, and a receiving preparation confirmation signal CFR according to the determination by the training state determining means.
, CFR/FTT signal transmission determining means for transmitting a training failure signal FTT or a command to transmit the CFR or FTT, and a storage means for storing that training has failed at least once, or the training failure signal FTT is transmitted at least once. The equalizer coefficient holding means and the training inhibiting means are configured to include a storage means for storing information to the effect that the CFR/FTT signal transmission determining means has transmitted a reception preparation confirmation signal CFR or a command to transmit the CFR. When one of the storage means outputs a signal indicating that the training has failed or a signal indicating that the training failure signal FTT has been sent,
3. A facsimile apparatus according to claim 1, wherein the equalizer coefficients of each modem are retained and training is prohibited.