JPH11122454A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately execute the transition from the reception of primary channel information to the reception of control channel information without using any expensive filter or the like in a communication equipment capable of ITU-T recomended V.34 communication. SOLUTION: A non-signal time between primary channel information and control channel information is measured by using a signal presence or absence detecting circuit 22. Then, when an RCP signal is detected during the reception of the primary channel information, or when a specific non-signal time between the primary channel information and the control channel information is detected, transition from the reception of the primary channel information to the reception of the control channel information is operated. Also, when a non-signal beyond the specific non-signal time is detected during the reception of the primary channel information, the reception of the primary channel is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to ITU-T Recommendation V. 34 relates to a communication device such as a facsimile device capable of communication.

[0002]

2. Description of the Related Art Conventional ITU-T Recommendation V. In the facsimile apparatus capable of performing the 34 communication, the transition from the reception of the primary channel information to the reception of the control channel information has been executed by detecting the RCP signal.

[0003]

However, if the transition from the primary channel information to the control channel information is performed in a state where the modem has not been able to demodulate correctly, the control channel information cannot be received and the communication is interrupted. There was a disadvantage that it would.

[0004] On the other hand, there has been proposed a method of shifting from reception of primary channel information to reception of a control channel by utilizing a difference between a frequency component of primary channel information and a frequency component of control channel information. However, this method has a problem that a filter for detecting the frequency is required, and the facsimile apparatus becomes expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a communication apparatus capable of appropriately shifting from receiving primary channel information to receiving control channel information without using expensive equipment.

[0006]

Means for Solving the Problems The first invention of the present application is:
ITU-T Recommendation V. 34 communication devices capable of communication,
Primary channel information receiving means, control channel information receiving means, signal presence / absence detecting means, and time detecting means for detecting a signal absence time between the primary channel information and the control channel information, and when receiving the primary channel information When detecting a specific non-signal time between the primary channel information and the control channel information, the process shifts to receiving control channel information.

Further, according to the second invention of the present application, in the first invention, when detecting no signal at the time of receiving the primary channel information, the training disable is turned on to continue receiving the primary channel information and one frame is received. When the above-mentioned valid frame is received, the training disable is turned off and the detection result of the no-signal time is determined. If it is determined that there is a specific no-signal time between the primary channel information and the control channel information, the training is disabled. The disable is turned off, and the operation shifts from receiving the primary channel to receiving the control channel.

The third invention of the present application is the first or second invention, wherein the specific no-signal time between the primary channel information and the control channel information is 70 msec.
c ± 5 msec.

Further, according to a fourth invention of the present application, in the first to third inventions, when receiving primary channel information, R
When a CP signal or a specific non-signal time is detected, the process shifts to reception of a control channel, and when a non-signal other than the specific non-signal time is detected during reception of primary channel information, reception of the primary channel is continued. I do.

The fifth invention of the present application is based on ITU-T Recommendation V. 34, a communication method using communication, comprising a primary channel information receiving step, a control channel information receiving step, a signal presence / absence detecting step, and a time detecting step of detecting a signal absence time between the primary channel information and the control channel information. When the specific no-signal time between the primary channel information and the control channel information is detected at the time of receiving the primary channel information, the process shifts to receiving the control channel information.

The sixth invention of the present application is based on ITU-T Recommendation V. 34, in a computer-readable storage medium storing a program for executing communication, a primary channel information receiving step, a control channel information receiving step, a signal presence / absence detecting step, And a time detecting step of detecting a signal-free time. When receiving a primary channel information, when detecting a specific non-signal time between the primary channel information and the control channel information, control is performed to shift to the reception of the control channel information. And a program for storing the program.

In the present invention as described above, ITU-T Recommendation V. In the 34th communication, the transition from the primary channel information to the control channel information can be reliably detected in a state where the modem has not been able to demodulate correctly by using the signal presence / absence detecting means which can be realized at a low cost. , Smooth communication can be realized at low cost.

[0013]

FIG. 1 is a block diagram showing the configuration of a facsimile apparatus according to one embodiment of the present invention.

An NCU (network control unit) 2 connects to a terminal of the line in order to use the telephone network for data communication and the like.
It controls connection of a telephone exchange network, switches to a data communication path, and holds a loop. The NCU 2 connects the telephone line 2a to the telephone 4 when the signal level (signal line 20a) from the control circuit 20 is “0”, and connects the telephone line 2a when the signal level is “1”. It is connected to the facsimile machine side.
In a normal state, the telephone line 2a is connected to the telephone 4 side.

The hybrid circuit 6 separates the transmission system signal and the reception system signal, sends the transmission signal from the addition circuit 12 to the telephone line 2a via the NCU 2, and transmits the signal from the other party via the NCU 2. The signal is received and sent to the modem 8 via the signal line 6a.

The modulator / demodulator 8 is based on ITU-T Recommendation V. 8,
V. 21, V.I. 27ter, V.I. 29, V.I. 17, V.I.
34, and performs modulation and demodulation based on
Each transmission mode is designated by the signal line 20c. The modulator / demodulator 8 receives a signal output on a signal line 20b, outputs modulated data on a signal line 8a, receives a received signal output on a signal line 6a, and outputs demodulated data on a signal line 8b. Output.

The ANSam transmission circuit 10 is a circuit for transmitting an ANSam signal. When a signal of signal level "1" is output to the signal line 20d, the ANSam transmission circuit 10 transmits the ANSam signal to the signal line 10a and outputs the ANSam signal to the signal line 20d. When the signal of the signal level “0” is being output, no signal is output to the signal line 10a.

The addition circuit 12 inputs the information of the signal line 8a and the information of the signal line 10a, and adds the result of the addition to the signal line 12a.
a. The reading circuit 14 reads an image of a document and outputs the read image data to a signal line 14a. The recording circuit 16 is for sequentially recording information output to the signal line 20e line by line.

The memory circuit 18 is used for storing raw information of read data or encoded information, and also for storing received information or decoded information.

The signal presence / absence detection circuit 22 receives the information on the signal line 6a and outputs a signal of signal level "1" to the signal line 22a when detecting the presence of a signal of -43 dBm or more. If the signal is less than the signal line 22a
To output a signal of signal level "0". In the signal presence / absence detection circuit 22, the concept of integration is not introduced in the determination of the presence / absence of a signal.

The control circuit 20 complies with the ITU-T Recommendation V. 34, which controls the entire facsimile apparatus capable of communication, has primary channel information receiving means and control channel information receiving means, and outputs a signal between the primary channel information and the control channel information from the signal presence / absence detecting circuit 22. When no time is detected, and when a specific no-signal time between the primary channel information and the control channel information is detected at the time of receiving the primary channel information, control for shifting to reception of control channel information is performed.

More specifically, upon detecting the absence of a signal at the time of receiving the primary channel information, the training disable is turned on, and the reception of the primary channel is continued.
When one or more valid frames are received, the training disable is turned off. At the same time, the detection time without this signal is determined, and the specific no-signal time (70 msec) between the primary channel information and the control channel information is determined.
When it is determined to be (c ± 5 msec), the process shifts from receiving the primary channel to receiving the control channel.

That is, when an RCP signal or a specific non-signal time is detected during reception of the primary channel information, the process shifts to control channel reception, and a non-signal other than the specific non-signal time is detected during reception of the primary channel information. If so, the reception of the primary channel is continued.

FIGS. 2 to 4 show the control circuit 20 as described above.
3 is a flowchart showing a control flow.

First, the operation is started in S0, and in S2, a signal of signal level "0" is output to the signal line 20a to output CML.
Turn off. In S4, a signal of the signal level “0” is output to the signal line 20d, and the ANSam signal is not transmitted.

In S6, it is determined whether or not an incoming call has been selected. If no incoming call has been selected, the process proceeds to S8, performs other processing, and proceeds to S2.

When an incoming call is selected, the process proceeds to S10,
A signal of signal level “1” is output to the signal line 20a,
Turn L on. In S12, transmission of the ANSam signal, in S14, reception of the CM signal, in S16, transmission of the JM signal, and in S18, reception of the CJ signal are sequentially performed. Then, in S20, the training disable for the modem 8 is set to off.

Next, in step S22, the primary channel is received. In step S24, information on the signal line 22a is input.
It is determined whether or not a signal is detected. If a signal is detected, the process proceeds to S26. If a signal is not detected, the process proceeds to S22.
Proceed to.

At S26, the primary channel is received. Then, in S28, it is determined whether or not a valid one frame is detected.
0, and if no valid one frame is detected, S32
Proceed to.

In S30, the training disable is turned off for the modem 8. Then, in S32, information on the signal line 22a is input, it is determined whether or not no signal is detected, and no signal is detected. If so, the process proceeds to S40, and if the presence of a signal is detected, the process proceeds to S34.

At S34, the RCP of the primary channel
It is determined whether a signal has been detected or not. If no RCP signal has been detected, the process proceeds to S26. When the RCP signal is detected, the process proceeds to S36, and shifts to control channel reception.
In S38, it is determined whether there is a next page. If there is a next page, the process proceeds to S22. If there is no next page, the process proceeds to S2.

In S40, an instantaneous interruption timer for measuring an instantaneous interruption time is started. In S42, the training disable for the modem 8 is turned on.

In step S44, the primary channel is received. In step S46, information on the signal line 22a is input.
It is determined whether the presence of a signal is detected. If the presence of a signal is detected, the process proceeds to S48, and if the presence of a signal is not detected, the process proceeds to S44.

In S48, the instantaneous interruption timer is stopped, and
In 50, the instantaneous interruption time measured by the instantaneous interruption timer is 65 m
It is determined whether it is 75 msec from 75 sec.
If it is 75 msec from sec, the process proceeds to S52, and S52
Then, the training disable for the modem 8 is turned off. If it is not 65 msec to 75 msec, the process proceeds to S26.

The operation of the control circuit as described above is performed by the CPU in the control circuit based on a program stored in ROM, RAM, or the like in the control circuit. It may be stored in an external storage medium such as a disk or a hard disk, or a magneto-optical disk or a CD-ROM, fetched into a control circuit by a dedicated reading device, and executed by a CPU in the control circuit.

In the above embodiment, a stand-alone type facsimile apparatus has been described as an example. However, the present invention is not limited to this. For example, a copy function, an electronic file function, and a data processing function are combined with a communication function. The present invention can be applied to data communication control in a comprehensive data processing system. Further, the present invention can be similarly applied to a communication device separated from a reading circuit and a recording circuit.

[0037]

As described above, according to the present invention,
ITU-T Recommendation V. In communication 34, it is possible to reliably detect the transition from primary channel information to control channel information in a state where the modem has not been able to demodulate correctly by using signal presence / absence detection means that can be realized at low cost.
Communication can be continued, and smooth communication can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a flowchart showing the operation of the embodiment.

FIG. 4 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

 2 ... NCU, 4 ... telephone, 6 ... hybrid circuit, 8 ... modulator / demodulator, 10 ... ANSam transmission circuit, 12 ... addition circuit, 14 ... read circuit, 16 ... recording circuit, 18 ... memory circuit, 20 ... control circuit, 22 ... Signal presence / absence detection circuit.

Claims (6)

[Claims] 1. An ITU-T Recommendation V. 34 communication device capable of communication, comprising: primary channel information receiving means, control channel information receiving means, signal presence / absence detecting means, and time detecting means for detecting a signal absence time between primary channel information and control channel information. A communication apparatus characterized in that upon receiving primary channel information, detecting a specific non-signal time between the primary channel information and the control channel information, and shifting to receiving control channel information. 2. The method according to claim 1, wherein upon detecting primary signal information, when no signal is detected, training disable is turned on to continue receiving primary channel information. When one or more valid frames are received, training is disabled. In addition to turning off the disable, the detection result of the no-signal time is determined, and if it is determined that the specific no-signal time is between the primary channel information and the control channel information, the training disable is turned off and the primary channel is disabled. A communication device which shifts from reception to control channel reception. 3. The method according to claim 1, wherein the specific no-signal time between the primary channel information and the control channel information is 70 msec ± 5 msec.
A communication device characterized by the following. 4. The method according to claim 1, wherein when receiving an RCP signal or a specific no-signal time during reception of the primary channel information, a transition is made to reception of a control channel. A non-signal other than the specific no-signal time, the reception of the primary channel is continued. 5. The method according to ITU-T Recommendation V.5. 34. A communication method using 34 communications, comprising: a primary channel information receiving step, a control channel information receiving step, a signal presence / absence detecting step, and a time detecting step of detecting a signal absence time between the primary channel information and the control channel information. A communication method characterized by detecting a specific non-signal time between primary channel information and control channel information when receiving primary channel information, and shifting to control channel information reception. 6. ITU-T Recommendation V. 34. A computer-readable storage medium storing a program for executing communication, comprising: a primary channel information receiving step, a control channel information receiving step, a signal presence / absence detecting step; A time detecting step of detecting a signal-free time, and when receiving a primary channel information, detecting a specific non-signal time between the primary channel information and the control channel information, and performing control to shift to reception of the control channel information. A computer-readable storage medium having stored therein a program for executing the program.