JP3870520B2 - Communication terminal device with external device connection function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication terminal device such as a facsimile machine connected to an external device such as a personal computer.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a facsimile machine, which is a communication terminal device, has been widely used in offices and general households because arbitrary image data can be transmitted and received. On the other hand, devices such as personal computers (hereinafter referred to as “PCs”) are also multifunctional. Things have been developed and used in a variety of applications. Recently, a facsimile apparatus that can connect a personal computer as an external apparatus has been developed, and both can be linked.
[0003]
In this case, the facsimile machine functions as a scanner of a personal computer if the scanned and scanned image data is transmitted to the personal computer side, and enables processing and correction of the image data on the personal computer, while the image data created on the personal computer side is If it is received and printed out on a predetermined recording paper set in advance, it functions as a printer of a personal computer. Further, since the facsimile apparatus is connected to a communication line such as a telephone line and is capable of facsimile communication, the facsimile data can be transmitted and received by a personal computer. In this case, it functions as a modem of the personal computer.
[0004]
[Problems to be solved by the invention]
However, when the conventional facsimile apparatus functions as a modem for a personal computer, the facsimile communication procedure cannot be normally executed and correct communication may not be performed.
That is, the facsimile apparatus receives a command from the personal computer side, and transmits a signal to a telephone line or the like according to the command, or receives a signal, but particularly when switching the speed of the modem from a low speed to a high speed, The command sent from the personal computer could not be detected in time, and subsequent signals could not be sent or received.
[0005]
Specifically, in the case of facsimile transmission, after receiving a command from a personal computer and sending a DCS (digital command signal) to the line with a low-speed signal (300 bps), a predetermined period (75 ms) is assumed to have no carrier, Although it is necessary to send TCF (training check) with a high-speed signal (4800 bps, etc.), there was a case where a command to send this TCF was sent from a personal computer after a predetermined period of time. .
[0006]
The present invention has been proposed in view of such circumstances, and has an external device connection function that enables correct communication by transmitting and receiving signals to and from a communication line without waiting for a command from the external device. An object is to provide a communication terminal device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the communication terminal device with an external device connection function according to claim 1 detects an AT command sent from the external device and transmits a signal corresponding to the command through the communication line. Based on the detection of the FSK transmission command “AT + FTH = 3” from the external device, the communication terminal apparatus transmits a DCS signal through the communication line, and then does not detect the high-speed transmission start command “AT + FTH = 96”. When the time has elapsed, transmission of the TCF signal is started.
[0008]
According to a second aspect of the present invention, in the communication terminal device according to the first aspect, the communication speed of the TCF signal transmitted when a predetermined time elapses without detecting the high-speed transmission start command is either the FSK transmission command or the transmitted DCS signal. It determined based on the crab stored information.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an example of a basic configuration of a communication terminal device with an external device connection function according to the present invention.
Here, the configuration of a facsimile apparatus F is shown as an example of a communication terminal apparatus, and a personal computer PC, which is an external apparatus, is connected to a connector via a communication line L according to a standard such as RS-232C, and a communication line La (telephone) Line). With such a configuration, the facsimile apparatus F performs facsimile communication through the communication line La, and also functions as a modem, printer, and scanner of the personal computer PC.
[0011]
In the present invention, the external apparatus is not limited to the personal computer PC, and may be any apparatus having a communication function with the facsimile apparatus F. For example, Asynchronous Facsimile DCE Control which is a standard (EIA / TIA-578). It is only necessary that data communication can be realized using a protocol such as Standard Service Class I (service class 1). In this service class 1, a command (AT command) for setting and controlling the facsimile apparatus F by the data terminal apparatus and a response returned from the facsimile apparatus F in response to this command are defined. The data transmission from both sides is enabled by serial transmission. The service class 1 protocol will be described below as an example.
[0012]
In the figure, 1 is composed of a CPU and the like, and is a main control unit that performs signal control of each unit, 2 is an NCU that performs network control such as sending a dial signal to the communication line La, and 3 is for facsimile communication of image data Modem for modulating / demodulating signals, 4 is composed of DRAM, etc., image memory for storing image data for facsimile communication, 5 is composed of SRAM, etc., and is a RAM for storing temporary data generated during execution of processing , 6 is a ROM that stores a device control program necessary for the operation of the facsimile machine F, 7 is a liquid crystal display device, etc., and a display unit for displaying the operation state and operation procedure of the facsimile machine F, 8 Is equipped with various keys such as numeric keys and function keys, and an operation unit for making various input settings for this facsimile apparatus F, 9 using a CCD or the like The reading unit 10 scans an original with a scanner and outputs dot image data converted into black and white binary, and 10 records image data received by facsimile from another facsimile machine or image data received from a personal computer PC on a recording sheet ( A recording unit 11 for printing out) is an external interface unit that includes a connection port such as RS-232C and controls communication with a personal computer PC connected via a communication line L in accordance with a predetermined protocol.
[0013]
In such a configuration, when the facsimile apparatus F receives data from another facsimile apparatus or the like through the communication line La after the initial setting is performed from the personal computer PC via the external interface unit 11 in advance, While the data is transmitted to the personal computer PC as it is, the data received from the personal computer PC is called and transmitted through the communication line La according to the transmitted dial data.
[0014]
Thus, when the facsimile apparatus F functions as a modem of a personal computer PC, the present invention has a feature. FIG. 2 shows a facsimile transmission (embodiment of the present invention) and FIG. 3 shows a facsimile reception (reference example) . Each operation is shown in a flowchart, which will be described below. In FIG. 2, when a “FSK (frequency modulation) transmission command” command (for example, AT + FTH = 3) is received from the personal computer PC side via the external interface unit 11, a low speed (300 bps, modulation method: V.21 ch.2) sends a DCS signal, and then waits to receive a “high-speed transmission start command” command (for example, AT + FTH = 96) from the personal computer PC.
[0015]
It is necessary to send the TCF to the communication line La after a predetermined silence period (about 75 ms) after sending the DCS, and if a “high-speed transmission start command” command is received from the personal computer PC, In order to communicate at the high speed (9600 bps, modulation method: V.29) specified in the above, the modem 3 is opened, and high-speed transmission training (TCF transmission) is performed in order to perform phase synchronization. If no command is received within that period, the modem speed in the DCS sent in step 101 is detected, the modem 3 is opened at this speed, high-speed transmission training is performed, and high-speed transmission is performed (100 and above). ~ 107).
[0016]
That is, here, the main control unit 1 transmits the first signal (DCS) through the communication line La based on the detection of the first command (FSK transmission command) from the personal computer PC, and then the second command ( The transmission of the second signal (TCF) is started without waiting for the detection of the high-speed transmission start command) (modem open). Opening the modem 3 means that the main control unit 1 sets the transmission or reception communication speed to be operated in the internal command register of the modem 3.
[0017]
Further, the main control unit 1 determines the type of the second signal (TCF) to be transmitted based on information (modem speed) stored in the first command (FSK transmission command) from the external device. In the figure, the modem speed is detected from the DCS transmitted to the communication line La by the FSK transmission command, but there is no difference from the detection from the FSK transmission command command. Thus, if the TCF that is originally transmitted based on this command is transmitted without waiting for the high-speed transmission start command command, the transmission of the signal is delayed as in the conventional case, resulting in a communication error. There is nothing.
[0018]
When the high-speed transmission start command command, which is the second command, is received from the personal computer PC after the modem is opened, the modem has already been opened and transmission has started, so no processing is performed for this command. It is only necessary to return a normal response to the personal computer PC side. FIG. 3 shows an operation when a signal is received through the communication line La as a reference example . Here, the type of command received from the personal computer PC side, not the flow according to the procedure as shown in FIG. Shows the flow when the processing is distributed.
[0019]
If the RS-232C data is received from the personal computer PC side via the external interface unit 11 and the data is valid as an AT command, the command is analyzed and the processing is distributed (200 to 202).
If the analyzed command is a “FSK reception command” command (for example, AT + FRH = 3), a signal is received at low speed (300 bps, modulation method: V.21 ch.2) through the communication line La, and a DCS signal is received. When it is received, the modem 3 is immediately opened at the speed declared in the DCS and waits for TCF (training check) from the transmission side (203 to 206). Thus, in the present invention, the modem 3 is opened when the modem speed is known so as to start signal reception without receiving a “high-speed reception start command” command from the personal computer PC side.
[0020]
When receiving a “high-speed reception start command” command (for example, AT + FRH = 96) from the personal computer PC side, the modem 3 is connected to communicate at the high speed (9600 bps, modulation method: V.29) specified by the command. Open, receive TCF, and start high-speed reception (207-210). At this time, if the modem 3 has already been opened in step 206, high-speed reception (210) is performed only by waiting for a "high-speed reception start command" command that should be received (207).
[0021]
If the command received from the personal computer PC side is not the “FSK reception command” command but the “high-speed reception start command” command, the process predetermined by the protocol is executed for each command (211). ).
Here, the main control unit 1 receives the first signal (DCS) through the communication line La based on the detection of the first command (FSK reception command) from the personal computer PC, and then receives the second command (high speed The reception of the second signal (TCF) is started without waiting for the detection of the reception start command) (modem open).
[0022]
The main control unit 1 determines the type of the second signal (TCF) to be received based on the information (modem speed) stored in the received first signal (DCS) (206). Thus, if the modem open (206) that starts TCF reception is performed based on this command without waiting for the high-speed reception start command command, TCF reception can be performed as in the conventional case. Communication error does not occur.
[0023]
【The invention's effect】
As can be understood from the above description, the communication terminal device with external device connection function according to claim 1 of the present invention transmits the first signal based on the detection of the first command from the external device. Since the second signal is transmitted without waiting for the detection of the second command, the transmission timing of the second signal is not delayed and normal communication can be performed.
[0024]
In claim 2, since the type of the second signal to be transmitted after transmitting the first signal is determined based on information stored in the first command from the external device, the second command is detected. Even if not, the second signal can be transmitted.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a configuration of a communication terminal device with an external device connection function according to the present invention.
FIG. 2 is a flowchart showing a basic operation according to the present invention of a communication terminal device with an external device connection function .
FIG. 3 is a flowchart showing a reference example of basic operation of a communication terminal device with an external device connection function .
[Explanation of symbols]
F: Facsimile machine 1 ... Main control unit 11 ... External interface unit L ... Communication line PC ... Personal computer La ... Communication line

Claims (2)

In a communication terminal device that detects an AT command sent from an external device and transmits a signal corresponding to the command through a communication line,
Based on the detection of the FSK transmission command “AT + FTH = 3” from the external device, after a predetermined time has elapsed without detecting the high-speed transmission start command “AT + FTH = 96” after transmitting the DCS signal through the communication line , A communication terminal device with an external device connection function, wherein transmission of a TCF signal is started. The communication terminal device according to claim 1,
A communication speed of a TCF signal to be transmitted when a predetermined time has elapsed without detecting the high-speed transmission start command is determined based on information stored in either the FSK transmission command or the transmitted DCS signal. A communication terminal device with an external device connection function.

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