JPH04324744A - Terminal communication equipment - Google Patents

Abstract

PURPOSE:To prevent a wrong dialing due to repetition of ON/OFF of a terminal ready signal by interrupting line connection over a prescribed period when the ON/OFF of the terminal ready signal is repeated. CONSTITUTION:A terminal ready signal monitor means 18 monitors on/off of a terminal ready (ER) signal sent from a terminal equipment 10. When the repetition of on/off of the ER signal is confirmed, a switch control means 20 controls a switch means 16 to disconnect a line 12 and a MODEM means 14 over a prescribed period. Through the constitution above, even when the on/off of the ER signal is repeated due to noise or mis-operation, since the line connection is interrupted over a prescribed period, the exchange surely recognizes line interruption and then a wrong dialing is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to devices used for data communications between terminals, such as modems and network control devices.

[0002] Data communication using automatic dialing has become widespread in terminals such as personal computers.

[0003] The automatic dialing is performed by the terminal sending an automatic dialing command to this type of device, or by operating an automatic dial switch or redial switch provided on this type of device. ing.

Furthermore, in the case of a terminal that cannot send commands, automatic dialing is performed using an ER signal (terminal ready signal).

[0005]

[Prior Art] If a dial number is registered in advance in this type of device (modem or network control device) and the terminal cannot send an automatic dialing command, the registered number will be registered when the ER signal changes from off to on. The number is auto-dialed and the line is disconnected when the ER signal changes from off to on (AA-type auto-dialing procedure).

Alternatively, the telephone dials manually and then changes the ER signal from off to on to switch from the telephone to this type of device (MM-type automatic dialing procedure).

[0007]

[Problem to be solved by the invention] ER caused by noise or incorrect operation
When the signal repeats on and off as shown in Figure 5(A),
When this type of device repeats line connection and disconnection at a cycle T1 close to the speed of dial pulses, as shown in FIG. 2B, the exchange mistakenly recognizes this as dialing, resulting in an erroneous call.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a device of this type that can prevent wrong calls when the ER signal is repeatedly turned on and off.

[0009]

[Means for Solving the Problems] In order to achieve the above object, as shown in FIG. A modulation/demodulation means 14 demodulates the received signal and sends it to the terminal 10, a switch means 16 connects and disconnects the line 12 and the modulation/demodulation means 14, and a terminal ready state indicates whether or not the terminal 10 is ready for communication. Terminal ready signal monitoring means 18 that monitors on/off of the signal, and switch control that controls the switch means 16 to disconnect the line 12 and the modulation/demodulation means 14 for a certain period of time when it is confirmed that the terminal ready signal is repeatedly turned on and off. Means 2
0.

0010

According to the present invention, when the ER signal is repeatedly turned on and off, the disconnected state of the line 12 is maintained for a period during which the exchange can recognize that the line 12 has been disconnected.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the terminal communication device according to the present invention will be described below with reference to the drawings.

FIG. 2 shows a modem 22 to which the present invention is applied, and the modem 22 connects the DTE 10 and the line 12.
It is inserted between.

The transmission signal of the DTE 10 is given to a modem 14 (MODEM) via a DTE interface 24, modulated by the modem 14, and then sent to the line control unit 16.
(NCU) to the line 12.

[0014] Also, the received signal is taken from the line 12 via the line control unit 16 to the modulation/demodulation unit 14, demodulated by the modulation/demodulation unit 14, and then sent to the DTE 10 via the DTE interface unit 24.

Furthermore, the ER signal sent by the DTE 10 is given to a control section 26, and the line control section 16 is controlled by this control section 26.

As a result, connection and disconnection with the line 12 are performed by the line control section 16 in response to the ER signal.

FIG. 3 shows the control procedure of this embodiment (control section 26), and FIG. 4 shows its operation.

In FIG. 3, the state of the ER signal is first checked (step 300), and when it is confirmed that the ER signal has changed from off to on as shown in FIG. The line connection operation (off-hook, on-hook when the ER signal changes from on to off) is performed as shown in FIG. 4(B) (step 302).
).

Then, the state of the ER signal is checked again (
Step 304), and dialing is performed when the ER signal is on (Step 306).

[0020] Furthermore, if it is confirmed that the ER signal is off at this time (step 308), as shown in FIG.
The state in which the connection to the line 12 remains disconnected is maintained (steps 308, 310).

After that, when it is confirmed that the line recovery guarantee time T2 has elapsed and the ER signal is on (step 3
00), line connection is made for dialing (step 306) as shown in FIG. 4(B) (step 302).
).

Here, in FIG. 4(A), the ER signal repeats on/off at a cycle T1 close to the speed of the dial pulse, but as shown in FIG. 4(B), the guaranteed line recovery time T2 (approximately 3 Since the state in which the connection to the line 12 remains disconnected is maintained until the time period (seconds) has elapsed, the exchange can reliably recognize this state (line disconnection).

[0023] Therefore, even if the ER signal is repeatedly turned on and off due to noise or erroneous operation, no wrong call will be made.

[0024]

[Effects of the Invention] As explained above, according to the present invention, even if the ER signal repeatedly turns on and off due to noise or erroneous operation, the line connection will be disconnected for a certain period of time, so the exchange will ensure that this state (line disconnection) is maintained. Therefore, it is possible to prevent mistaken calls due to this.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the invention.

FIG. 2 is an explanatory diagram of the configuration of the embodiment.

FIG. 3 is a flowchart illustrating the operation of the embodiment.

FIG. 4 is a time chart explaining the operation of the embodiment.

FIG. 5 is a time chart illustrating the prior art.

[Explanation of symbols]

10 DTE 12 Line 14 Modulation/demodulation section 16 Line control section 22 Modem 24 DTE interface 26 Control section

Claims (1)

[Claims] 1. Modulation/demodulation means (14) that modulates a transmission signal received from a terminal (10) and sends it to a line (12), demodulates a received signal received from the line (12) and sends it to the terminal (10). ), a line (12) and a modulation/demodulation means (14)
), a terminal ready signal monitoring means (18) for monitoring the on/off of a terminal ready signal indicating whether or not the terminal (10) is ready for communication; switch control means (20) that controls the switch means (16) to disconnect the line (12) and the modulation/demodulation means (14) for a certain period of time when it is confirmed that the signal is repeatedly turned on and off;
A terminal communication device characterized by: