JPH0243396B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a communication control device capable of communicating with both G-facsimile (hereinafter referred to as FAX) and teletext.

(Prior Art) Conventionally, GFAX for image communication and Teletex for document communication have been widely used as document communication terminals.

For GFAX communication control, CCITT's T30
Terminal devices that implement communication procedures in accordance with the recommendations are being used.

Here, the communication procedure in accordance with CCITT's T30 recommendation is a facsimile communication control procedure that uses a binary code method to set up and release facsimile calls based on the High Level Data Link Control (HDLC) format. It is.

Furthermore, for teletex communication control, a terminal device is used that implements communication procedures in accordance with the recommendations of the Ministry of Posts and Telecommunications' Notification No. 889.

Here, the communication procedure in accordance with the recommendation of Ministry of Posts and Telecommunications Notification No. 889 is a modem that transmits at 4800 b/s or 2400 b/s using a carrier frequency of 1800 Hz using an 8-phase or 4-phase differential phase modulation method. HDLC using
This is a control procedure for performing document communication based on the frame format of .

(Problem to be solved by the invention) On the other hand, in order to combine an image document handled by GFAX and a character document handled by Teletex and to be able to communicate with both documents, it is necessary to install a device that controls each communication. It was necessary to prepare separately.

That is, in order to handle both image documents and text documents with one device, two communication control devices must be provided, which increases the amount of hardware and increases costs.

Structure of the Invention (Means for Solving the Problems) In order to solve these problems, the present invention realizes both GFAX and Teletex communication functions with one communication control unit, and has the following features. The drawings will be explained in detail.

(Example) Fig. 1 is a block diagram of one embodiment of the present invention device, in which 1 is a 8-phase or 4-phase differential phase modulation method using a carrier frequency of 1800Hz, and 4800b/s or 4800b/s or
A modem that transmits at 2400 b/s or 9600 b/s or 7200 b/s using a mixed amplitude and phase modulation method using a carrier frequency of 1700 Hz (hereinafter referred to as V.27tar modem) and frequency shift. A modem (hereinafter referred to as V.221 modem) that performs synchronous transmission at 300 b/s using binary modulation according to the V.221 method, 2
3 is an I/O (input/output unit), 4 is a communication network, 5 is a GFAX, and 6 is a teletext.

In the communication control device of the present invention, GFAX
and Teletex communication control are the same for both.
Focusing on what is achieved using the V.27tar modem,
It is possible to realize communication control of both GFAX and Teletex using one V.27 modem and V.21 modem.

First, the equipment consists of one V.27tar modem and a V.21
The device is composed of a modem 1, a communication control section 2 for controlling the modem 1, and an input/output section 3, and is connected via a communication network 4 to a GFAX 5 and a teletext 6, or between the devices.

FIG. 2 is an example of a control flow diagram of the called side of the apparatus of the present invention.

When a call is received from GFAX or Teletex via the communication network of this device, first an incoming response signal (G
For fax, CDE is sent, and for teletext, AST) is sent.

CDE or AST responds to the operator handling the other device with a tone indicating the characteristics of this device, and GFAX's AST is set to transmit 1800Hz for 2.6 to 4 seconds, and this device responds to both. For example, 1800Hz
It is easy to realize this by using a signal such as sending out 2100 Hz for 1.5 seconds followed by sending out 2100 Hz for 1.5 seconds.

Subsequently, the called side sends an initial identification signal to the calling side device. This indicates to the other party the modem functions and procedure functions of the called party, and is called a DIS signal in the case of GFAX, and an MCI signal in the case of Teletex.

The GFAX DIS signal is a two-frequency signal (0 to 1850Hz,
1 at 1550Hz) and is transmitted according to the HDLC frame.

FIG. 3 is a diagram showing a procedure for transmitting a GFAX DIS signal (binary code information).

FIG. 4 is a diagram showing an example of the structure of GFAX binary code information.

When transmitting a DIS signal, a preamble signal is transmitted prior to the binary code signal, and its length is stipulated to be at least 1 second. Furthermore, regarding the contents of the preamble signal, it is specified that if the called party has a tonal signal function, a tonal preamble should be used, and if it has only a binary signal function, it should be followed by an HDLC flag sequence of an appropriate length. There is.

It is specified that such a DIS signal is to be repeated at 3 second intervals until timeout (35 seconds ± 5 seconds) until command information is received from the other party.

FIG. 5 is a diagram showing the MCI signal transmission procedure of Teletex, where CST is a call identification signal, AST is an incoming response signal, and MCI is a modem function display signal.

Here, if a frame including the incoming response signal AST or the modem function display signal MCI is detected, the transmission of the call identification signal CST is stopped.

Teletex's MCI signals are transmitted according to HDLC frames using a phase modulation method using a carrier frequency of 1800Hz.

It is specified that such an MCI signal is to be repeated up to six times at three second intervals until command information is received from the other party.

In FIG. 2, which is an example of a control flow diagram of the called side of the device of the present invention, in order to send these two types of initial identification signals DIS and MCI, DIS
and MCI will be sent alternately and repeatedly.

Regarding the number of repetitions, in order to meet the two conditions of the GFAX timeout of 35 ± 5 seconds or the teletext timeout of 6 repetitions, DIS and MCI should each be at least 3 times and no more than 10 times. It is considered sufficient to take this into account.

As an alternative to Figure 2, in a V.27tar modem, instead of alternating the DIS and MCI signals, the V.21 modem for DIS follows the 300 b/s
It is also possible to easily implement a method in which the two-frequency signal and the 1800 Hz differential phase modulation signal for MCI are sent in parallel.

In this way, while transmitting the DIS signal and the MCI signal, the response signal returned from the other party's calling side is monitored during the pause period of each signal, and the returned signal is the DCS of the GFAX communication control procedure. signal or teletex communication control procedure.
By identifying which one is the MFI signal, it is possible to determine whether the other party's calling party is GFAX or Teletex. Such identification can be easily accomplished by monitoring the received signals of the V.27tar modem and V.21 modem.

FIG. 6 is an example of a control flow diagram on the calling side when the calling function using both the GFAX and Teletex functions is realized in the same device configuration as shown in FIG. 1.

First, when making a call as a GFAX, in accordance with the recommendations, a 1100 Hz signal that lasts 0.5 seconds is transmitted as a calling tone (CNG) signal every 3 seconds.

During this time, it monitors the response from the called party and waits until a timeout (30 to 40 seconds) to detect a DIS signal. If a DIS signal is detected, a response signal is returned according to the GFAX procedure.

On the other hand, when making a teletext call, as shown in Figure 5, a call identification signal (CST) is used.
The 1800Hz modem carrier wave lasts 0.5-0.7 seconds as repeated every 1.5-2.0 seconds pause period. During this time, it monitors the response from the called party and waits until a timeout (30-45 seconds) to detect an MCI signal.
If an MCI signal is detected, a response signal is returned according to the teletext procedure.

Therefore, by acting like this, 1
Using one V.27tar modem, it is possible to realize communication control that enables both GFAX and Teletex communication, both originating and terminating.

Effects of the Invention As explained above, according to the present invention, one
Using V.27tar modem and V.21 modem,
Since it is possible to communicate incoming calls with both fax and teletext, one device can be used for both purposes rather than using each device separately, so there is an advantage that document communication services can be provided economically.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of one embodiment of the device of the present invention;
3 is a diagram showing an example of the control flow on the called side of the device of the present invention, FIG. 3 is a diagram showing the sending procedure of the GFAX DIS signal, FIG. 4 is a diagram showing an example of the configuration of GFAX binary code information, and FIG. Figure 5 shows Teletex
A diagram showing the MCI signal sending procedure, Figure 6 is GFAX
2 is a diagram showing an example of a control flow on the calling side when a calling function using both the teletext and teletext functions is realized in the device configuration of FIG. 1. FIG. 1...V.27tar modem and V.21 modem, 2...communication control unit, 3...input/output unit, 4...communication network, 5...G facsimile, 6...teletex.

Claims (1)

[Claims] 1. Using an 8-phase or 4-phase differential phase modulation method, using a carrier frequency of 1800 Hz, 4800 b/s or
A carrier frequency of 1700Hz using a modem that transmits at 2400b/s or a mixed amplitude and phase modulation method.
Using a modem that transmits 9600b/s or 7200b/s and binary modulation using a frequency shift method.
G facsimile communication that uses a binary code system and a modem that performs synchronous transmission at 300 b/s to set up and release facsimile calls based on the High Level Data Link Control (HLDC) format. With the control procedure and the 8-phase or 4-phase differential phase modulation method,
Using carrier frequency 1800Hz, 4800b/s or
It is equipped with a teletext communication control procedure for performing document communication based on the HLDC format using a modem that transmits at 2400 b/s, and after an incoming call from a communication line is connected, an identification signal from the called side is transmitted. means for alternately repeating one cycle of the DIS signal of the G facsimile communication control procedure and one cycle of the MCI signal of the teletext communication control procedure 3 to 10 times, and during the pause period of the DIS signal and the MCI signal; In this method, the calling side is provided with means for detecting a signal transmitted from the calling side and identifying whether it is a DCS signal of the facsimile communication control procedure or an MEI signal of the teletext communication control procedure. , G facsimile or teletext, and is capable of receiving and communicating with either of them. 2 Using 8-phase or 4-phase differential phase modulation method, using a carrier frequency of 1800Hz, 4800b/s or
A carrier frequency of 1700Hz using a modem that transmits at 2400b/s or a mixed amplitude and phase modulation method.
Using a modem that transmits 9600b/s or 7200b/s and binary modulation using a frequency shift method.
G facsimile communication that uses a binary code system and a modem that performs synchronous transmission at 300 b/s to set up and release facsimile calls based on the High Level Data Link Control (HLDC) format. With the control procedure and the 8-phase or 4-phase differential phase modulation method,
Using carrier frequency 1800Hz, 4800b/s or
It is equipped with a teletext communication control procedure for performing document communication based on the HLDC format using a modem that transmits at 2400 b/s, and after an incoming call from a communication line is connected, an identification signal from the called party is transmitted. means for simultaneously transmitting the DIS signal of the G facsimile communication control procedure and the MCI signal of the teletex communication control procedure in a superimposed manner on one line, and a rest period of each of the DIS signal and the MCI signal. The system is equipped with means for detecting a signal transmitted from the calling side and identifying whether it is a DCS signal of the G facsimile communication control procedure or an MFI signal of the teletext communication control procedure. A communication control device characterized in that it determines whether a call is a G facsimile or a teletext, and can receive a call and communicate with either of them. 3 After placing a call to the communication line, a means for detecting the signal received in response from the called side and identifying whether it is a DIS signal of the G facsimile communication control procedure or an MCI signal of the teletex communication control procedure. Claims 1 or 2, characterized in that, by providing the above, it is possible to determine whether the called party is a G facsimile or a teletext, and to enable incoming and outgoing communication with either of them. The communication control device described.