JPS63166358A - Communication control equipment - Google Patents

Abstract

PURPOSE:To decrease under run or picture error due to picture data transfer delay by sending a reply signal to an opposite terminal type identification signal to a reception buffer after a prescribed quantity of picture data is received in a reception buffer in the MODEM sequence in succession to the call. CONSTITUTION:The transmission of a DSC (digital instruction signal) being a reply signal of an opposite identification signal to a DIS (digital identification signal) is awaited till prescribed quantity of picture information is received in the MODEM sequence after the call in the facsimile mode. It has been difficult in a conventional controller to send a data from a host to a communication function within 6sec after a CFR (reception preparation confirmation) or an MCF (message confirmation), but it is made possible. Moreover, it is possible to send a correct picture by providing a buffer data of a prescribed capacity or over to a communication function to be correspondent to the change in the transmission speed of the data to the line depending on the fines of the picture.

Description

[Detailed description of the invention] (Field) The present invention relates to a communication control device.

[Prior Art] Conventionally, there is a method of communicating data from a personal host such as a personal computer or a word processor using a telephone line. In this case, if the other party uses a facsimile, there may be a transmission delay.

〔the purpose〕

The present invention eliminates the above-mentioned inconvenience.In the facsimile mode, in the modem sequence after making a call, the DCS signal, which is a response signal to the DIS signal, which is a destination identification signal, is not transmitted until a predetermined amount of image information is received from the host. This reduces underruns or image "r-" caused by delays in image data transfer by two times.

This is particularly effective when communicating host code data using facsimile procedures. In this case, the code data is converted into image bit data and sent to the facsimile. Also, if the other party's device is a computer, etc., communicate with the computer.

A communication procedure for word processor communication is selected from the ROM and communication is executed. In this case, the code data is sent without converting the data format.

〔Example〕

FIG. 1 is a conceptual diagram of this system. 1 is the host part,
It is connected with the communication function section 3 and the cable 2. The host transfers the control command and image data to the communication function unit 3, and transmits the image to the FAX via the public telephone line 4. The image data from the host uses MH compressed image data. The communication unit surface part of 3 is T, 3
Protocol and modem to support 0F order, NC
It consists of a U section and has a G3 facsimile transmission function. Further, the communication device section 3 is provided with a communication section (not shown). A handset 6 is connected to the communication function section 3, and when the host is not connected to the communication device f needle section 3, the CPU of the communication function section 3 detects that the host is not connected. Then, the relay of the NCU section is switched to the communication section side and operates as a telephone.

Further, the CPU in the upper part 3 of the communication device switches the relay of the NCU section to the communication section side based on a switching instruction from a changeover switch (not shown), and allows the communication through the handset 6 to be carried out by mouth. That is, when the host is not connected, the communication function section 3 operates as a telephone as in the case of yE.The normal sequence of automatic call origination and reception using the binary procedure of the G3 facsimile will be explained with reference to FIG. The left side is the calling side, and the right side is the called side.

After the calling party calls the other party using dial number 48,
When the other party is connected, it sends a CNG (calling tone).

When the called side responds, it similarly sends a CHD (called station identification) tonal signal.

Subsequently, the called party sends a binary DIS (digital identification signal) signal to present communication conditions. The calling party uses the DIS
It is stipulated that the called party should continue sending the signal for 30 to 40 seconds after 3 seconds until it sends a DC3 (digital command signal) in response to the signal.

The calling side sends a DCS signal according to the contents of the DIS, sets the communication speed and specifications, sends training and data, and checks whether the called side can receive it correctly.

If the called party can receive the call correctly, it will return a CFR (reception readiness confirmation) binary signal. If it cannot receive it, it returns an FTT (training failure) binary signal, starts from DC3 again, and lowers the transmission rate if necessary. The calling party is C.
If the image signal is not transmitted within 6 seconds after receiving the FR, the line will be disconnected as an error, so the communication function must receive the image data from the host at this point. According to CCITT T, 4, 03 FAX uses a compression method called MH or MR for image signals.

Normally, MH compression is performed and an EOL (end of line code) is attached to each line. Also, the minimum transmission time for one line of an image is Dis.

Defined by DC3, 0,5,10,20°40, m
The value of esc is set. Similarly, the maximum transmission time for one line is specified as 5 seconds, so if the data transfer rate from the host is slow, a fill (consecutive 0's) is inserted between the data and the EOL to wait. However, in the past, data delays were rare, so even with commercially available facsimile machines, if a long fill was inserted, an error would occur and the previous data would be inserted due to a line error, or the drive of the paper feed motor would be stopped, causing the image to become defective. Often consecutive. Therefore, it is not possible to slow down the transmission speed too much by adding a fill.

When the image data is completed, θ in the figure indicates EOM (end of message), MPS (multi-page signal), EOP (
each binary signal (end of procedure). In the case of EOP, the called party sends an MCF (message confirmation) and the calling party sends a DCN.
(disconnection command) is sent and the line is disconnected.

Also, if you want to send more images under the same conditions, send MPS and M
The next page data will be sent within 6 seconds after receiving the CF. EOM is used when it is desired to send further images under different conditions, and the procedure returns to the first DIS.

FIG. 3 shows an example of the sequence of the system of the present invention. The communication function section with the personal computer has an R5232C interface and uses asynchronous serial signals. Commands and transmission control are based on the recommended communication method for personal computer communication equipment (hereinafter JUST-
(PC procedure). Starting with L (excluding LRS)
Everything is the same except for the commands. First, the communication function section is initialized by an LMD command containing the local telephone number and user ID, and an LRS response is received from the communication function section. Next, use the CNR command to enter the telephone number in the parameter field and make a call.

When the other party's FAX is connected, the communication function section sends an RNC confirmation signal to the host side and at the same time sends CNG to the other party's FAX. When receiving CED and then DIS from the other party's FAX, the communication function section receives the contents of DIS from the host in the form of an LRA communication signal.

The host transmits information for DC3 according to DIS using LPT commands, including encoding method, recording status, recording length, maximum transmission rate, resolution, and page retransmission capability (here, the transmission speed can be arbitrarily selected according to the performance of the own modem). However, if the speed is not slower than the data transmission speed between the host, an image error or underline will occur, so the speed specification information between the host and the communication function must be read and a value lower than that must be set as the contents of the DIS.As information (For systems that cannot read the LMD, the speed at which the LR3 response is sent to the LMD may be measured.)
Send to communication function department.

LPT also invites you to confirm the previously sent page. For the first LPT, an LRS response is returned without parameters. After this, the host sends image data one after another to the parameter section using a CDT (data sending command) command. The communication function section inserts a fill due to data shortage from the host by proceeding with the sequence below DC3 after checking whether more than a predetermined amount of data has accumulated in the internal buffer or receiving an LPT command for sending the next page. and prevents underrun.

After the host finishes sending the image data, it will send out data one after another after the LPT command. After transmitting the image signal, the communication function section checks the next page data amount in the internal buffer as described above, and if it is less than a predetermined value, outputs EOM, and if it has enough stored, it continues to transmit the image signal by MPS.

Continuation of image data from host <LDE (data end command)
The last page is notified to the communication function by a signal. The LRS parameters for the second and subsequent LPT commands are p r
c=o means MCF, and PIC=1 means RTN (reception failure notification). When PIC=1, LPT
If there is a retransmission capability declaration inside, image data transmission (CDT) can be performed by interrupting the transmission of the next page and sending it to the LPT again. Since it is stipulated to start from DIS when RT'H is present, the data delay of the host can be saved as well. Approximately 2 to 2 bytes are preferred as a buffer.

〔Effect of the invention〕

It has been very difficult to send data from the host to the communication function within 6 seconds after CFR or MCF, but the present invention makes it possible.

Further, depending on the fineness of the image, it is possible to transmit the correct image by having a predetermined amount or more of buffer data for the communication function that should accommodate changes in the data transmission speed to the line.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of the entire system, Figure 2 is a sequence diagram of the G3 facsimile after it is connected to the telephone network, Figure 3 is a sequence diagram of the procedure of the present invention, and Figure 4 is a flowchart of the sequence focusing on communication functions. It is a diagram.

Claims (1)

[Scope of Claims] In a communication control device having a facsimile communication procedure and having a modem unit and an NCU unit for sending data from a personal host, a response signal to a callee type identification signal is transmitted in a modem sequence following a call, A communication control device that transmits image data after receiving a predetermined amount of image data in a reception buffer.