JPH0355071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a multifunctional telephone device for a data terminal that can perform various functions such as transactions and voice calls with a host computer.

(b) Conventional technology In recent years, multi-function telephone devices for data terminals have begun to be adopted in credit card verification and banking operations. "Application to Communication" discloses the configuration and functional outline of the conventional device.

Since such devices are often installed in stores, it is desirable to prevent unauthorized use by third parties, but conventional devices have not taken any measures.

(c) Problems to be Solved by the Invention The applicant has developed a latching relay circuit that is set or reset in response to the operation of a predetermined key on a keyboard, and a dial circuit that is activated depending on the state of the latching relay circuit. The idea was to prevent third parties from using the device by setting up a limited dialing mode by installing a limited dialing circuit consisting of a circuit means for stopping the dialing function, and allowing a specific person who is familiar with the device, such as a store owner, to set the limited dialing mode. .

However, key operations for executing specific functions such as speed dialing and transactions are usually known only to a specific person and not to a third party. In addition, in the case of speed dialing, there are not many harmful effects when a third party uses it. Nevertheless, with the method described above, once the limited dialing mode is set, a specific person cannot even perform a specific function. Therefore, it is necessary to reset the latching relay circuit immediately before executing a specific function, and then set the latching relay circuit after the execution is completed, which is cumbersome to operate. or,
There is also the possibility of forgetting to set the settings after completion, which is not very desirable from a security standpoint.

(d) Means for Solving Problems The present invention is provided with a bypass circuit that bypasses the latching relay circuit and forcibly restores the dial function of the dial circuit when a specific function is executed.

(e) Effect In the present invention, even if the latching relay circuit is set by a predetermined key operation and the limited dial mode is set, when a specific person executes a speed dial or a specific function of data communication, the dial function is disabled by the bypass circuit. is restored, so the purpose can be achieved by performing only normal key operations to execute a specific function. However, even if a third party performs a general dialing operation of sequentially pressing keys corresponding to a telephone number to make a voice call, the dialing function remains in a stopped state, making such use impossible. .

(f) Embodiment FIG. 1 is a block diagram showing the overall configuration of a telephone terminal device according to the present invention, in which 1 is a diode bridge circuit connected to a telephone line 2, and 3 is a piezoelectric circuit for receiving a call signal. A ringer detection circuit drives the buzzer 4; 5 is a switch inserted into the telephone line 6; 7 is a communication circuit connected to the telephone line 6; 8 and 9 are a transmitter and receiver; 10 is a dial pulse switch 11 that turns on and off. a pulse dialer that controls and sends out dial pulses corresponding to a telephone number; 12 corresponds to a telephone number;
A tone dialer 13 that sends out a DTMF (dual tone multi-frequency) signal is connected to the telephone line 6, and the output voltage is set to the power supply voltage V _DS
This is a regulator circuit that supplies the dialers 10 and 12 and the telephone communication circuit 7 as a main terminal.

In addition, 14 is a keyboard equipped with multiple operation keys such as function keys, character keys, and numeric keys;
5 is a CPU that constitutes a control circuit together with I/O interfaces 16 and 17, 18 is a display device, and 19 is a RAM 20 for storing communication data sent and received with the host computer.
, an EPROM 21 that stores various programs such as an initialization program, and an E ² PROM 22 that is a non-volatile memory that stores data that you do not want to erase even when the power is turned off, such as a telephone number; 23 is a communication system; 24 is a dialer control circuit that controls the dialing functions of the pulse dialer 10 and tone dialer 12 in accordance with the output signal of the I/O interface 16; 25 is a dialer control circuit that converts data and telephone signals; Input the commercial power supply voltage and
5. It is a power supply circuit that supplies the power supply voltage V _DD to various parts such as the I/O interfaces 16 and 17 and the memory system 19, and the power supply voltage V _DS from the regulator circuit 13 is also supplied to the dialer control circuit 24. .

By the way, as the pulse dialer 10 and the tone dialer 12, for example, the dialer ICMK50992 and MK5089 manufactured by Mostek may be used, and these ICs have terminals for controlling the dial function on pin 17 and pin 2, respectively. Ori,
When the input signal to the 17th pin is at the "H" level or in the open state, and when the input signal to the 2nd pin is at the "L" level, the dialing function of each dialer is stopped.

FIG. 2 is a circuit diagram showing a specific configuration of the dialer control circuit 24.
The collector is connected to pin No. 2, the emitter is grounded, and the base is connected to the power supply potential through resistors 25 and 26.
Switching transistor 27 connected to V _DS
and a switching transistor 30 whose collector is connected to pin 17 of the pulse dialer 10, whose emitter is grounded via a switch 28, and whose collector is connected to the power supply potential _VDS via resistors 29 and 26; A switching transistor 31 whose collector is connected to the base of 30 and whose emitter is grounded, and resistors 25 and 2
The output is connected to the connection point P of 9, and the selection switch 32 selects between a pulse dialer and a tone dialer, and a signal from the I/O interface 16.
A latching relay circuit 33 is provided which is set and reset by CN1 and CN2, and the C terminal of the contact 34 of the latching relay circuit 33 is connected to the power supply potential V _DS via a resistor 35. The M terminals of diodes 36 and 37
are connected to the bases of switching transistors 27 and 31, respectively. These circuit means constitute a limited dialing circuit 42 that stops the dialing function of the dialer.

The dialer control circuit 24 is also provided with switching transistors 43 and 44 whose bases are applied with signals CN3 and CN4 from the I/O interface 16, respectively, and whose emitters are grounded. By connecting to the bases of switching transistors 27 and 31, a bypass circuit is constructed which bypasses latching relay circuit 33 and controls the input signal and OHT. In addition, 45 is selection switch 3
This is a signal line that inputs the selected state of No. 2 to the I/O interface 16 as a signal CN5, and is connected to the power supply potential _VDD via a pull-up resistor 46.

Furthermore, the E ² PROM 22 shown in FIG. 1 is configured to store a limited dial flag FG indicating whether the limited dial mode is set or canceled by a predetermined key operation. Write "1" and "0" when canceling.

Next, the operation of this embodiment will be explained.

Normally, the latching relay circuit 33 is in a reset state, the contact 34 is coupled to the B side, and the power supply voltage V _DS is not supplied to the terminal M. At this time, the limited dial flag FG is set to "0". In this state, when the selection switch 32 is set to the DTMF side as shown, the connection point P between the resistors 25 and 29 is grounded, so the switching transistors 27 and 30 are turned off, and both dialers 12, 1
Input signal of pin 2 and pin 17 of 0 and
Both OHTs are in an open state. Therefore, the tone dialer 12 becomes operational, and the pulse dialer 10 becomes inactive, stopping the dialing function.

If the selection switch 32 is set to the DP side, the connection point P
Since the power supply voltage V _DS is supplied to through the resistor, the switching transistors 27 and 30 are both turned on, and the input signal and OHT become "L". Therefore, in this case, the tone dialer 12 becomes inactive and the pulse dialer 10 becomes operable.

Thus, when the latching relay circuit 33 is in the reset state, one of the dialers is selected according to the selection switch 32.

However, when a predetermined key operation is performed on the keyboard 14,
For example, if you specify the limited dial mode by operating the keys ENTER → A3 → □1, the CPU 15 responds to this key operation by setting the output signal CN1 of the I/O interface 16 to "H" for a certain period of time.
At the same time, the dial limitation flag FG of the E ² PROM 22 is set to "1". When the signal CN1 becomes "H", the switching transistor 38 turns on,
A current flows through the set coil 39, the latching relay circuit 33 is set, and the contact 34 is connected to the M side. Therefore, the power supply voltage V _DS is
7 to the bases of switching transistors 27 and 31, turning these transistors on and further switching transistor 30
is turned off. Therefore, the input signal becomes "L", the input signal OHT becomes open, and both dialers 10 and 12 become inactive, stopping the dialing function.

Once the latching relay circuit 33 is set, it maintains the set state even if the power supply voltage V _DD from the power supply circuit 25 is cut off, so that the power supply voltage V _DD remains unchanged.
If the limited dialing mode is set while the power supply is being supplied, the dialing functions of the dialers 10 and 12 will remain stopped even if the power plug 26 is pulled out.

To cancel the limited dial mode, all you have to do is perform a predetermined key operation, for example, ENTER → A3 → □0. In response to this key operation, the CPU 15 controls the I/O interface 16 to output a signal.
Set CN2 to "H" level for a certain period of time and set limited dial flag FG to "0". When the signal CN2 becomes "H", the switching transistor 40
turns on, current flows through the reset coil 41,
The latching relay circuit 33 is in a reset state, and the contact 34 is connected to the B side. Therefore, one dialer selected by the selection switch 32 returns to the operable state.

Next, the operation when the speed dial or data communication function is executed will be explained.

To perform a speed dial, go off-hook, press the letter or numeric key corresponding to the person you want to dial, and then press the Dial Request key, or press the associated character with the host computer to perform a transaction. When the dial request key is pressed after pressing the key or number key and inputting communication data such as the date, credit number, amount, etc., the CPU 15 executes these specific functions as shown in the flowchart of FIG. It is determined that a key operation has been performed, and subsequent processing is performed.

That is, first, determine the limited dial flag FG,
It is determined whether or not the limited dial mode is selected, and when this mode is selected, the selection status of the selection switch 32 is read using the signal CN5. Signal CN5 is selection switch 32
When CN5 is on the DTMF side, it becomes "H" level, and when it is on the DP side, it becomes "L" level, and when CN5 is "H", the CPU 15 controls the I/O interface 16 and outputs the signal.
Signal when CN3 is “H” and CN5 is “L”
Set CN4 to "H".

When the signal CN3 becomes "H", the switching transistor 43 constituting the bypass circuit is turned on, and the base of the switching transistor 27 is forcibly set to "L" even if the latching relay circuit 33 is set. Therefore, the transistor 27 is turned off and the input signal is in an open state.
The dialing function of the tone dialer 12 is restored.

Furthermore, when the signal CN4 becomes "H", the switching transistor 44 constituting the bypass circuit is turned on, and even if the latching relay circuit 33 is set, the base of the switching transistor 31 is forced to "L". do. Therefore, the switching transistor 31 is turned off and the switching transistor 30 is turned on.
The input signal OHT becomes "L" and the dialing function of the pulse dialer 10 is restored.

After that, the CPU 15 sends the telephone number corresponding to the pressed letter or number key to the E ² PROM.
22 and sends it to the dialer 10 or 12 via the I/O interface 16, and the dialer sends out a dial signal corresponding to the telephone line 2. In the case of data communication, the CPU 15 turns the hook switches 5 and 28 off-hook. Thereafter, the CPU 15 converts communication data input from the keyboard 14 and temporarily stored in the RAM 20 into a telephone signal using the modem 23, and transmits the signal to the host.
The data received from the host is input to the modem 23 via the telephone line 2, converted to digital data, and displayed on the display 18.
Stored in RAM20.

When execution of such a speed dial function or transaction function is completed or the mode is canceled midway, the CPU 15 sets the signals CN3 and CN4 to "L". Therefore, after execution, switching transistor 4 of the bypass circuit
3 and 44 are turned off, the switching transistors 27 and 31 are again controlled according to the latching relay circuit 34, and both dialers 12 and 44 are turned off.
and 10 dial functions are again in a stopped state.
Therefore, even if a third party performs a normal dialing operation, the telephone cannot be answered.

By the way, one possible method for canceling the limited dial mode only when executing a specific function is to reset the latching relay circuit 33 once at the start of execution and reset it at the end of execution. If the power is cut off for some reason, the latching relay circuit 33 remains reset, and the dialer becomes operational from then on. However, in the present invention, the dial function is controlled without controlling the latching relay circuit 33, so even if the power is cut off, the dial function remains stopped.

Although only a keyboard is shown as an input device, a magnetic card reader or a password keypad may also be used.

(G) Effects of the Invention According to the present invention, it is possible to reliably prevent unauthorized telephone use by a third party while improving operability for a specific person. Further, even if the power is cut off while a specific function is being executed, the dialing function will continue to be stopped, which is very desirable from a security standpoint.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a detailed circuit diagram of the main part of this embodiment, and FIG. 3 is a flowchart showing the processing contents of this embodiment. Explanation of main drawing numbers, 2...Telephone line, 10...Pulse dialer, 12...Tone dialer, 1
4...Keyboard, 15...CPU, 24...Dialer control circuit, 25...Power supply circuit, 33...
Latching relay circuit.

Claims (1)

[Claims] 1. A keyboard with multiple operation keys, a dialing circuit that sends dialing signals to the telephone line,
For a data terminal, comprising: a latching relay circuit that is set or reset in response to a predetermined key operation on the keyboard; and circuit means for stopping the dial function of the dial circuit according to the state of the latching relay circuit. A multifunctional telephone device for a data terminal, characterized in that the multifunctional telephone device is provided with a bypass circuit that bypasses the latching relay circuit and forcibly restores the dialing function of the dialing circuit when a specific function is executed. .