JP2580081B2 - Telecommunications equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telecommunication device, such as a modem, connected between a terminal and a telephone line for transmitting and receiving data between the terminal and the telephone line. The present invention relates to a telecommunication device controlled by a command.

[0002]

2. Description of the Related Art Conventionally, in a telecommunication device of this type, for example, a modem, three types of "dial waiting time", "carrier waiting time", and "tone dial timing" are closely related to the technical standards of the telecommunication device. The constant is stored in each of the registers S6, S7, and S11 in the S register.

The AT command for reading / writing the S register is a basic command, and is used in all AT command type modems. And this A
The value of the S register can be set to an arbitrary value within a variable range by the T command.
A constant value within the variable range is given as an initial value to the registers S6, S7, and S11, and operation conforming to the technical standards is guaranteed as long as the register operates at the initial value.

FIG. 4 is a flowchart showing a processing operation in a command mode in the conventional modem. As shown in FIG. 4, the conventional modem performs the following processing when inputting an AT command.

[0005] That is, from the terminal via the TXD line,
AT command, for example, "Sr = n" (n
) Is input (step 31), it is checked whether the command is grammatically correct (step 32). If the command is grammatically correct, the command is executed. If the command is not grammatically correct (step 33), the command is ignored or an error is output (step 34).

[0006]

As described above, in the conventional modem, when an AT command is input,
Since it is only necessary to check whether the AT command is grammatically correct or not, all S registers can be rewritten by inputting a correct command.

Therefore, if registers such as the S6, S7, and S11 registers, which are related to the basic operation of the modem, are rewritten unnecessarily, there arises a problem that the modem deviates from technical standards.

In other words, when the values of these S registers are changed intentionally or by mistake with an S register write command, there is a possibility that the technical standards will not be satisfied depending on the set values.

The present invention has been made in view of such circumstances. For the S6, S7, and S11 registers, the S register write command is invalidated, and these values are completely fixed with initial values. A special AT command is prepared separately, and the special AT command is input to provide a telecommunication device capable of changing these three constants.

[0010]

FIG. 1 is a block diagram showing the configuration of the present invention. As shown in the figure, a telecommunications device 108 according to the present invention comprises a terminal 101 and a telephone line 1.
02, the terminal 101 and the telephone line 102
Storage means 103 for transmitting and receiving data to and from the AT, and for storing various constants including three specific constants related to the technical standards of the telecommunications device, controlled by AT commands; A modulating / demodulating means 104 for modulating a signal from the terminal 101 and sending it to the telephone line 102, demodulating a signal received from the telephone line 102 and sending it to the terminal 101, and an AT command for writing various constants. When an AT command is input, various constants are written in the storage unit 103 in accordance with the AT command, and the storage unit 10
3 according to the values of the various constants stored in the terminal 101.
The control unit 105 controls the modulation and demodulation unit 104 so that data is transmitted and received between the telephone and the telephone line 102, and receives a first special command set separately, and receives the first special command. In some cases, even if an AT command instructing writing of various constants is input thereafter, the specific three constants are invalidated, and an instruction is given to the control means 105 so that the values of the three constants are held at the initial values. Receiving the input of the second special command set separately from the holding means 106, when the second special command is input, the holding of the holding means 106 is released and the storage means 103
And release means 107 that enables writing of three specific constants to

The modem 104 according to the present invention
A conventionally known modulation / demodulation device is used as the device.

The control means 105, the holding means 106, and the releasing means 107 include a CPU, a ROM, a RAM,
It is convenient to use a microcomputer having an I / O port, and the storage means 103 is usually a RAM therein.

[0013]

According to the present invention, when the first special command is input, the values of the specific three constants are held at the initial values even after the AT command is input.

When the second special command is input, it is possible to write three specific constants into the storage means.

Therefore, the writing of the specific three constants relating to the technical standard into the storage means can be restricted by the special command, thereby preventing deviation from the technical standard due to erroneous writing.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. The present invention is not limited by this.

FIG. 2 is a block diagram showing the configuration of an embodiment in which the present invention is applied to a modem. In this figure, 1
Is a terminal such as a word processor or a personal computer, 2 is a telephone line, 3 is connected between the terminal 1 and the telephone line 2, and performs data transmission / reception between the terminal 1 and the telephone line 2; The modem itself controlled by commands.

Reference numeral 4 denotes an S register comprising a RAM. S
Register 4 contains S₀, S₁,…_,S _r, ..., each memory
These memories have various constants.
It can be stored. Of these memories, S6
"Waiting for dialing" related to the technical standards of the modem 3
"Interval", S7 "carrier waiting time", S11
“Tone dial timing” is stored
You. S6, S7, S11 of S register 4 are collected
Hereinafter, it is referred to as “reference S register”.

Reference numeral 5 denotes a modem front end (hereinafter referred to as a modem F / E) which modulates a signal from the terminal 1 and sends it to the telephone line 2 and demodulates a signal received from the telephone line 2 and sends it to the terminal 1. (Abbreviated).

Reference numeral 6 denotes a controller composed of a microcomputer including a CPU, a ROM, a RAM, and an I / O port.

Of the memories of the S register 4, the S6, S7 and S11 registers in which "dial wait time", "carrier wait time", and "tone dial timing", which are related to the technical standards of the modem 3, are respectively set. Details will be described below.

In the S6 register, there is set a waiting time (dial waiting time) from when the modem goes off-hook until dialing is started without confirming a dial tone.
According to the technical standards, “it must be 3 seconds or more” is required.
Generally, in a modem, the variable range of S6 is 2 to 255.
Many times are set to seconds, but setting S6 = 2, for example, violates the standard.

In the S7 register, a time (carrier waiting time) for the modem to wait for a response (carrier) from the other device after dialing the other device is set. According to the technical standard, this is set to "60 seconds". Within ”. Generally, most modems set the movable range of S7 to 1 to 255 seconds. However, setting S7 = 60 or more would violate the standard. Conversely, S7 is set to an initial value (30 to 5).
If it is set extremely smaller than 0 seconds, the other party may deviate from the standard (retransmission is performed up to twice in 3 minutes) when the other party dials again to the same number continuously without response (this is called retransmission). There is. In the case of the mode in which retransmission is continuously repeated, if the detection time of no carrier (= non-response to the other party) is short, the retransmission interval may be short, which violates the standard.

The length of the tone dial (pipopa sound) and the length of the sounding interval (tone dial timing) are set in the S11 register. Both numbers are equal and 1
Given by two numbers. The technical standards stipulate the length of the tone dial sound, the interval between the sounds, and the period of the sound obtained by summing the two.
It is 20 ms or more. The variable range of S11 is 20 to
In the case of 255, if S11 = 60 ms or less is set, the technical standard is not satisfied.

The controller 6 sends an AT command for writing various constants from the terminal 1 via the TXD line.
When the AT command is input and the AT command is input, various constants are written to the S register 4 in accordance with the AT command, and the terminal 1 is set in accordance with the values of the various constants set in the S register 4. Modem F so that data can be transmitted and received between
/ E5 is controlled.

Also, when a first special AT command set separately is input and the first special AT command is input, the fixed value of the reference S register stored in the S register 4 is fixed. Set the mode.

That is, after that, the S register 4
Even if an AT command instructing the writing of various constants is input to the "Dial wait time" stored in S6,
The three constants of “carrier waiting time” stored in S7 and “tone dial timing” stored in S11 are invalidated, and the contents of the S register 4 are changed so that the values of these three constants are held at the initial values. Hold.

Then, a second special AT which is separately set
When a command is input and a second special AT command is input, S6, S7 and S1 of the S register 4 are input.
1 is released and the S register 4
Writing of three constants of "dial waiting time", "carrier waiting time", and "tone dial timing" is enabled.

Next, the operation of the modem body 3 will be described. When an AT command is input via the TXD line on the terminal 1 side, the controller 6 interprets the AT command and controls each part of the modem according to the instruction of the command. At this time, constants necessary for the operation are stored in the S register 4.

After executing the command, the controller 6 returns a "response code" to the terminal 1 through the RXD line.
This state is called a command mode, and is not in a communication state with the partner modem.

When an AT command is appropriately input to enter a communication state with the other party, the data string input from the TXD line is not regarded as a command, and the modem F is directly sent as data to the other party.
/ E5, modulated and sent out to the telephone line 2. Also, the signal emitted by the other modem is demodulated by the modem F / E5 and transmitted to the terminal 1 via the RXD line.

The following two AT commands directly access the S register 4. Sr = n Write n to the Sr register Sr? Reads the contents of the Sr register

Next, the contents of the processing operation of the controller 6 will be described with reference to the flowchart shown in FIG.

When an AT command, for example, a write command of the S register 4 such as "Sr = n" (write n to the Sr register) is input from the terminal 1 via the TXD line (step 21), first, It is checked whether the command is grammatically correct (step 22).

If the command is not a grammatically correct command, the command is ignored or an error is output (step 23).
Next, it is checked whether the command is a reference S register write command for the S register 4 (step 24).

At this time, if it is not a write command for the reference S register, an instruction corresponding to the command is executed (step 25). It is checked whether or not it is (step 26).

If the mode is the fixed mode of the reference S register, the write command is ignored or an error is output (step 27). Is executed, and writing to the reference S register in the S register 4 is performed (step 25).

In this way, even if the command is grammatically correct, if the reference S register is in the fixed mode, only the reference S register ignores the write command or rejects the command as an error. Whether the reference S register is set to the fixed mode or not is determined by a first and second special A, which is different from the write command of the S register 4.
Set by T command.

The technical standard is not limited to satisfying the condition in the initial value. If the state can be changed, it is necessary to satisfy the condition in the entire variable range. In experiments and evaluation work, it is useful that various constants that determine the operation of the modem have a high degree of freedom that can be varied. However, in normal use, fixed values for the operation constants related to the technical level are sufficient. In view of these, in the present invention, the AT which writes the registers of S6, S7 and S11 related to the state of the art is written.
Commands are invalidated and these registers are fixed to ensure conformity with technical standards. Also, by inputting a special AT command for use for experiments and evaluations in an environment separated from the telephone line, S6, S
7, a write command to S11 can be made valid and can be set to a numerical value within a variable range. Further, when another special AT command is input, the settings of these three registers are returned to the initial fixed values again.
Write commands to the S7 and S11 registers can be invalidated.

As described above, the present invention achieves both the legality during normal use and the usefulness for research purposes.

[0041]

According to the present invention, writing of three specific constants relating to the technical standard to the storage means is restricted by a special command. Deviation can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of an embodiment in which the present invention is applied to a modem.

FIG. 3 is a flowchart illustrating a command processing operation according to the embodiment;

FIG. 4 is a flowchart showing a command processing operation in a conventional modem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal 2 Telephone line 3 Modem main unit 4 S register 5 Modem F / E 6 Controller

Claims (1)

(57) [Claims] 1. A telecommunications device connected between a terminal and a telephone line for transmitting and receiving data between the terminal and the telephone line and controlled by an AT command.
Storage means for storing various constants including three specific constants related to the technical standards of such telecommunications equipment, and modulating a signal from a terminal to send it to a telephone line and demodulating a signal received from the telephone line And an AT command for instructing writing of various constants. When the AT command is input, the AT command is input.
Various constants are written to the storage means in accordance with the command, and the modulation / demodulation means is controlled such that data is transmitted and received between the terminal and the telephone line in accordance with the values of the various constants stored in the storage means. The control means receives an input of a separately set first special command, and when the first special command is input, even if an AT command instructing writing of various constants is input thereafter, a specific three constants are input. Is invalidated, holding means for giving an instruction to the control means so that the values of the three constants are held at the initial values, and input of a second special command separately set,
A telecommunication device comprising: a release unit that releases the holding of the holding unit when the second special command is input, and enables writing of three specific constants to the storage unit.