JP2531544B2 - FAX data transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a communication system between fax machines (hereinafter referred to as FAX) connected by a high-speed line through a time division multiplexer (hereinafter referred to as TDM). , A fax data transmission method for transmitting and receiving the fax data.

[Conventional technology]

Fig. 5 shows "MITSUBISHI Service Manual FA-6600".
Series ”is a block diagram showing a configuration of a communication system applied to the conventional FAX data transmission method shown in p.92,
In the figure, 1a and 1b are FAX1, FAX2, 2a and 2b are modems connected to the FAX1 1a and FAX2 1b, respectively, and the modems 2a and 2b are connected via a low speed line 3.

Further, FIG. 6 is a diagram for explaining the operation of each modem 2a, 2b in the conventional FAX data transmission system, and includes RTS, CTS, and R.
LSD is a modem control signal, TXD is transmission data, and RXD is reception data. In addition, these modems 2a and 2b operate from left to right mode in the figure.

 Next, the operation will be described.

Here, the operation of the modem 2a as the transmitting modem will be described.

First, when the line with the other modem 2b is set by receiving the tone, the RXD for modem control of 300 bps from the modem 2b
(A) is received (300 bps reception mode), and TXD (B) for 300 bps modem control is transmitted (300 bps transmission mode). Then, after sending TXD (C) which is 9.6kbps FAX data (high-speed transmission mode), for controlling 300bps modem
RXD (D) is received (300bps reception mode), 9.6kbps
Send TXD (E) which is FAX data (high speed transmission mode). And then TXD for 300bps modem control
Send (F) (300bps transmission mode), receive RXD (G) for 300bps modem control (300bps reception mode),
Send TXD (H) for 300bps modem control again (300bps
s transmission mode), and ends the transmission operation.

On the other hand, the modem 2b on the receiving side reproduces the transmission clock of the modem 2a on the transmitting side from the change in the cycle of the transmitted fax data, and fetches the fax data in synchronization with this clock.

[Problems to be Solved by the Invention]

Since the conventional FAX data transmission method is configured as described above, the FAX data is not transmitted / received in the communication system between FAXes connected by the high-speed line via TDM. In the communication system of the configuration, the FA
When attempting to send and receive X data, the conventional FAX data transmission method has a problem in that not only fax data but also low-speed modem control data must be sent from the sending TDM to the receiving TDM.

The present invention has been made to solve the above problems, and in a communication system between fax machines connected by a high-speed line via TDM, low-speed data for modem control is also transmitted via the high-speed line together with fax data. The purpose is to obtain a fax data transmission method that enables transmission and reception.

[Means for solving the problem]

In the fax data transmission method according to the invention of the first aspect, in the sending TDM, the low speed data for modem control sent from the sending fax is converted to the same speed as the fax data and sent to the receiving TDM. It is the one.

Further, in the FAX data transmission method according to the second aspect of the present invention, in the transmission side TDM, the modem control low speed data sent from the transmission side FAX is sampled by the FAX data clock and transmitted to the reception side TDM. It is the one.

[Action]

The fax data transmission method according to the first aspect of the invention is
The low-speed data for modem control is speed-converted in the TDM on the transmission side and sent to the TDM on the reception side, so that the low-speed data for modem control can be transmitted and received at the same speed as the fax data.

In the fax data transmission method according to the second aspect of the invention, low-speed data for modem control is faxed in the TDM on the sending side.
The data is sampled by the data clock and sent to the TDM on the receiving side, so that the low-speed data for controlling the modem can be transmitted and received via the high-speed line at a low speed.

Example of Invention

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a communication system applied to a fax data transmission system according to an embodiment of the first and second inventions, and a conventional communication system (FIG. 5).
The same or corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 3a and 3b are low-speed lines, 4a and 4b are modems connected to TDM1 5a and TDM2 5b, 5a and 5b are high-speed lines connected via high-speed line 6, and TDM1, TDM2 and 6 are high-speed lines, respectively. Reference numeral 7 is a high-speed clock on the high-speed line 6.

Next, the operation of the invention of the first claim will be described with reference to the data sequence of FIG.

Here, a case where FAX data is transmitted from FAX1 1a to FAX2 1b will be described.

First, the modem 4b receives a tone via the low-speed line 3b to set the line with the partner modem 2b of FAX2 1b,
RXD (A) for modem control of 300 bps is received from the modem 2b and sent to TDM2 5b. 300bps received on this TDM2 5b
RXD (A) for modem control of the same as the FAX data 9.6kbps
To the TDM15a via the high-speed line 6 after speed conversion (hereinafter referred to as speed conversion). The speed order conversion is performed as shown in FIG.

In the case of FAX data, since there is a training signal at the beginning, if there is no training signal, it is data for modem control, so TDM1 5a has the same RXD of 9.6 kbps as FAX data.
(A) is speed-converted to 300 bps (hereinafter referred to as speed reverse conversion) and sent from the modem 4a to the modem 2a via the low-speed line 3a. The inverse speed conversion in this case is performed using a FIFO as shown in FIG. 3 (b). When the modem 2a receives the RXD (A), the RXD (A) receives the modem 4a as shown in FIG.
I think that it came from, and sends TXD (B) for modem control of 300 bps to the modem 4a, and thereafter, the communication operation of FIG. 3 is performed between the modem 2a and the modem 4a. When TDM1 5a receives the TXD (B) for modem control of 300 bps, it performs speed forward conversion and transmits it to TDM2 5b via the high speed line 6. Since this TXD (B) is data for modem control (the training signal is not attached first), TDM2 5b is the TXD (B).
(B) is subjected to speed reverse conversion and transmitted from the modem 4b to the modem 2b via the low speed line 3b. And the modem 2b is this TXD
Think of (B) as data for controlling the modem from the modem 4b,
After that, the communication operation of FIG. 3 is performed with the modem 4b.

Next, the FAX data (C) from FAX1 1a is transferred to the modem 2a.
From the TDM1 5a via modem 4a, at 9.6kbps
FAX data (C) is sent through TDM2 via high-speed line 6 as it is.
Sent to 5b. Then, the fax data (C) is sent as it is (because the training signal is included) from the modem 4b to the modem 2b and the fax 21b via the low-speed line 3b.

Conversely, the modem 2b sends RXD (D) to the modem 4b, which sends it to the TDM 25b. For TDM2 5b, this 300b
When RXD (D) of ps is received, speed forward conversion is performed, the speed is converted to TDM1 5a via the high speed line 6, the speed is inversely converted by this TDM1 5a, and the modem 4a to the modem 2a via the low speed line 3a,
The RXD (D) is transmitted.

When the modem 2a receives the RXD (D), it thinks that the RXD (D) shown in FIG. 3 is transmitted from the modem 4a, and transmits the FAX data (E) to the modem 4a, and the TDM1
By 5a, it is transmitted to TDM2 5b via the high-speed line 6 as it is. The TDM2 5b transmits the received FAX data (E) as it is (because it has a training signal) from the modem 4b to the FAX2 1b connected to the modem 2b via the low speed line 3b.

Next, the modem 2a is a TXD for controlling the modem of 300 bps.
(F) is transmitted to the modem 4a via the low speed line 3a, and TDM1 5
a performs speed forward conversion and transmits to the TDM 25b via the high speed line 6. When the TDM2 5b receives the TXD (F), the speed is inversely converted and transmitted from the modem 4b to the modem 2b via the low speed line 3b. When the modem 2b receives the TXD (F), it thinks that it has been transmitted from the modem 4b, and transmits RXD (G) of 300 bps to the modem 4a.

This RXD (G) is subjected to speed forward conversion by TDM2 5b (since no training signal is attached), and is transmitted to TDM1 5a via the high speed line 6. This will cause TDM1 5a to
The speed of D (G) is inversely converted and transmitted from the modem 4a to the modem 2a via the low speed line 3a.

Finally, when the modem 2a receives the RXD (G), it thinks that the RXD (G) in FIG.
(H) is sent to the modem 4a, and the communication operation between the modem 2a and the modem 4a ends, while in the TDM15a, the TXD of 300 bps is transmitted.
(H) is speed-converted and transmitted to the TDM2 5b via the high speed line 6, and in this TDM2 5b, the speed reverse conversion of the TXD (H) is performed and the modem 4b to the modem 2b via the low speed line 3b. send.
Then, when the modem 2b receives TXD (H), it thinks that it is transmitted from the modem 4b and terminates the communication operation between the modem 4b and the modem 2b.

 Next, the operation of the invention of the second claim will be described.

According to the second aspect of the present invention, instead of the speed-order conversion operation (FIG. 3 (a)) for converting the above 300 bps modem control data into the same speed as the 9.6 kbps FAX data,
Data for modem control of 0 bps is sampled by a high speed clock for fax data of 9.6 kbps as shown in FIG. 4 and can be transmitted through the high speed line 6 at a low speed. On the other hand, according to the invention of the second claim, instead of the speed inverse conversion (FIG. 3 (b)) for speed-converting the 9.6 kbps modem control data into the 300 bps modem control data. , 9.6kbps modem control data 300bps
The modem control low-speed clock is used to enable reception via the high-speed line 6.

Also, in FIG. 4, (a) is a low-speed clock for modem control, (b) is 300 bps data for modem control,
(C) is a high-speed fax data clock of 9.6 kbps, and (d) is the sampling result.

〔The invention's effect〕

As described above, according to the invention of the first aspect, the transmitting side
Receiving side TDM by converting low speed data for modem control with TDM
Since it is transmitted to the modem, there is an effect that the low speed data for controlling the modem can be transmitted and received at the same speed as the FAX data.

Further, according to the invention of the second aspect, the low-speed data for modem control is sampled by the TDM on the transmitting side by the clock for FAX data and is sent to the TDM on the receiving side. There is an effect that it can be transmitted and received through the high speed line as it is.

[Brief description of drawings]

FIG. 1 shows an embodiment of the invention of the first and second claims.
FIG. 3 is a block diagram showing a configuration of a communication system applied to a FAX data transmission system, FIG. 2 is a data sequence for explaining the operation of the FAX data transmission system according to an embodiment of the invention of claims 1 and 2, and FIG. Is a diagram for explaining the speed conversion operation in the invention of the first claim, FIG. 4 is a diagram for explaining the sampling operation in the invention of the second claim, and FIG. 5 is applied to the conventional FAX data transmission system. FIG. 6 is a block diagram showing the configuration of a communication system for communication, and FIG. 6 is a diagram explaining the operation of each modem in the conventional FAX data transmission system. In the figure, 1a and 1b are faxes 1 and 2, 2a, 2b, 4a and 4b are modems, and 3
a and 3b are low speed lines, 5a and 5b are TDM1, 2 and 6 are high speed lines. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

(57) [Claims] 1. One of the time division multiplexers connected via a low speed line of one fax machine, and the other time division multiplexer connected to the other fax machine via a low speed line. In a communication system between fax machines connected via a high-speed line, the one time division multiplexing apparatus transmits low-speed data for modem control transmitted from the one fax machine via a low-speed line to the modem. FAX data transmission system characterized by inputting with a low-speed clock for transmission and converting the speed to the other time division multiplexing device with a clock for sending out to a high-speed line and sending out. 2. One of the time division multiplexers connected to one fax machine via a low speed line, and the other time division multiplexer connected to the other fax machine via a low speed line. In a communication system between fax machines connected via a high-speed line, one of the time division multiplexers transmits the low-speed modem control data sent from the one fax machine via the low-speed line to the fax data. FAX data transmission method characterized by sampling with a high-speed clock for transmission, and sending out to the other time division multiplexing device via the high-speed line.