JPS62208746A - Mis-changeover preventing system - Google Patents

Abstract

PURPOSE:To surely prevent a malfunction by switching a private line into an exchange line after a correct backup exchange line is established with a prescribed terminal equipment. CONSTITUTION:A tone generator 30 and a tone detector 31 are provided respectively to opposed dial backup devices 3, 4 in the data transmission sending data between data communication equipments 100a and 100b in use with 4-wire private lines 7a, 7b, and the dial backup device 3 uses 2-wire exchange lines 8a, 8b set at first when the private line is disconnected to send the output of its own toner generator 30, and when the opposite dial backup device 4 uses its own tone detector 31 to detect a tone, the 2-wire exchange lines 8a, 8b set next are used to send back the output of its own tone generator 30. When the dial backup device 3 detects a tone by the detector 31 and after a prescribed time elapses when the dial backup device 4 sends back the output of the generator 30, each MODEM is switched from the private lines 7a, 7b to the two exchange lines 8a, 8b.

Description

[Detailed Description of the Invention] [(Modification)] In a dial backup device that backs up a dedicated line with two exchanged lines, switching is performed by checking with both the incoming and outgoing devices to prevent erroneous switching. do.

[Industrial application field]

The present invention relates to preventing malfunction of automatic call switching of a dial backup device during data transmission.

[Conventional technology]

In an online data transmission system using a modem, when a dedicated line (four-wire type) goes down, backup is performed using a switched line. In this case, the device that determines and switches between connecting the modem to a dedicated line or connecting to a switched line where it is confirmed that the other party is answering by telephone is called a dial pack amplifier device.

Hereinafter, the dial bank up device will be referred to as DBU.

FIG. 3 is a diagram showing an example of a conventional DBU.

In the figure, 1 is a host, 2.5 is a modem, 3.4 is a dial backup device, 6 is a terminal, 7 is a dedicated line,
8 is a switched line, and 9 to 12 are telephones, respectively. The same symbols represent the same objects throughout all the figures below.

When a host 1 with a modem 2 and a terminal 6 with a modem 5 are performing data communication using a dedicated line 7, the system shown in the figure is used to perform bank up in the event that the dedicated line 7 is disconnected for some reason. , dial backup device 3
, and 4 are provided.

When the dedicated line 7 is disconnected, the operator on the host 1 side hooks off the telephone 9 and calls the telephone ↓1 on the terminal 6 side, then hooks off the telephone 10 and calls the telephone 12 on the terminal 6 side. .

There are three types of response operations on the receiving side after this: manual type and automatic type.

In the case of a manual type, in response to this call, the operator at terminal 6 hooks off telephones 11 and 12, confirms the call by telephone, operates DBU 4, and connects modem 5 from leased line 7 to switched line 8. Switch to.

Further, the operator on the host 1 side confirms that the switched line 8 has been established, operates the DBU 3, and switches the modem 2 from the dedicated line 7 to the switched line 8.

FIG. 4 is a diagram showing an example of an automatic switching operation on the receiving side of a conventional DBU.

In the figure, 20 is a control unit, 21 and 22 are ringer detectors, respectively.
23 is a switching relay, 23a is a contact of the switching relay 23, 2
4 is a switching relay, 24a is a contact of the switching relay 24, 25
is a switching relay, 25a is a contact of the switching relay 25, 26 is a switching relay, and 26a is a contact of the switching relay 26.

Since the dedicated line 7 is disconnected, the operator of the first host hooks off the telephone 9 and calls the telephone 11 on the terminal 6 side.
The ringer detector 21 in the DBU 4 is activated, and when the operator on the host 1 side hooks off the telephone 10 and calls the telephone 12 of the six terminals, the ringer detector 22 is activated.

After confirming the operation of the ringer detectors 21 and 22, the control unit 20 in the DBUA operates the switching relays 23 to 26,
The respective contacts 23a to 26a are switched. As a result of this, the modem 5 is switched from the dedicated line 7 to the switched line 8.

In this case as well, the operator on the host 1 side confirms that the switched line 8 has been established, operates the DBU 3, and connects the modem 2 to the leased line 7.
switch to switched line 8.

In Fig. 4, the switching relays 23 to 26 are respectively controlled by
Only the contacts 23a to 26a thereof are illustrated, and the main bodies of the switching relays 23 to 26 are not illustrated.

[Problem that the invention seeks to solve]

However, with conventional DBUs on the receiving side, if there is an incoming call on two exchanged lines, the call is automatically switched, so even if the two lines receive a call from the wrong party, the call is automatically switched to the other line. There was a drawback of doing this.

[Means for solving problems]

The above problem arises when data is transmitted between the data communication devices 100a and 100b using the 4-wire dedicated line (7a, 7b), and as shown in FIG. 4 and tone generator 3 respectively
0 and a tone detector 31 are provided, and when the dedicated line is disconnected, for example, the dial backup device 3
The output of the own tone generator 30 is sent out using a wire switching line, and when the other party's dial backup device 4 detects the tone by the own tone detector 31, the next set 2 is sent.
The output of the own tone generator 30 is sent back using a wire switching line, and the dial backup device 3 is connected to the own tone detector 3.
When a tone is detected by 1, the dial backup device 4 sends back the output of its own tone generator 30, and after a certain period of time has elapsed, the dial backup device 4 connects each modem to the dedicated line 7a.
, 7b to the two switched lines.

[Effect]

According to the present invention, switching is performed only when two exchange lines are set up with the correct party, so malfunctions can be completely prevented, and a person who knows the called party's phone number can deliberately make a prank call to back up the call. The effect is that normal operation is no longer disturbed.

〔Example〕

FIG. 1 is a diagram showing the principle of an erroneous switching prevention system according to the present invention.

FIG. 2 is an explanatory diagram of the operation of the DBU according to the present invention.

In the figure, 30 is a tone generator, 31 is a tone detector, 32
is a control unit, 27 is a switching relay, and 27a is a switching relay 27
The contacts 7a and 7b are dedicated lines (2W), 8a and 8, respectively.
b is a switched line (2W).

In the present invention, a tone generator 30, a tone detector 31, and a switching relay 27 are provided in a conventional DBU.

The present invention will be described in detail below with reference to FIGS. 1 and 2.

As mentioned above, since the dedicated line 7 is of the 4W format, it is divided into the dedicated lines 7a and 7b, and the exchanged line 8 is also divided into exchanged lines 8a and 8b, both of which are connected to the DBU 3 side. Connect the lines displayed as lines 8a and 8b to D.
On the BUA side, dedicated lines 7b, 7a, switched line 8b
, 8a. Note that the x mark in FIG. 1 indicates a switching point.

Also, the contact positions of each relay in Figure 2 are dedicated line 7a,
This is the state when using 7b.

Assume that all the dedicated lines 7 are disconnected.

- The original author on the host 1 side hooks off the telephone 9 and calls the telephone 11 on the terminal 6 side via the switched line 8a.

In the DBU 4, when the ringer detector 21 receives the signal via the exchange line 8b, the control unit 32 sets the hook-off state, and the relay 2
6 is operated to connect the tone detector 31 to the exchange line 8b through its contact 26a.

(2) Next, by operating the DBU 3, the control unit 32 operates the relay 25 and sends the output of the tone generator 30 to the exchange line 8a through its contact 25a.

The tone detector 31 of the DBU 4 receives the tone via the switched line 8b.

(2) The operator on the host 1 side turns off the telephone 10 and calls the telephone 12 on the terminal 6 side via the switched line 8b. After the call, the control unit 32 operates the relay 26 and closes the contact 26.
The tone detector 31 is connected to the exchange line 8b by a.

In the DBU 4, when the ringer detector 22 receives the signal via the exchange line 8a, the control unit 32 sets the hook-off state.

(2) In the DBU 4, when the control unit 32 confirms that the own tone detector 31 has already received a tone, it operates the relay 25, and sends the output of the own tone generator 30 to the exchange line 8a through its contact 25a.

(2) The tone detector 31 built into the DBU 3 receives the tone via the exchange line 8b.

- DBU3 performs switching after receiving this tone. That is, the control section 32 drives the relays 23, 24, 27, switches the modem 2 from the dedicated line 7 to the switched line 8 (8a and 8b) through the contacts 23a and 24a, and switches the output of the tone generator 30 through the contacts 27a. disconnect from the line.

■After the DBU4 outputs a tone for a certain period of time, the control unit 3
2 drives relay 23, 24, 27, and its contact 23a
, 24a connects the modem 2 from the leased line 7 to the switched line 8.
(8a and 8b), and the output of the tone generator 30 is disconnected from the line by the contact 27a.

〔Effect of the invention〕

As explained in detail above, according to the present invention, malfunctions can be reliably prevented because the dedicated line is switched to the switched line after confirming that a correct backup switched line has been established with a predetermined terminal. It has a big effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of an erroneous switching prevention system according to the present invention. FIG. 2 is an explanatory diagram of the operation of the DBU according to the present invention. FIG. 3 is a diagram showing an example of a conventional DBU. FIG. 4 is a diagram showing an example of an automatic switching operation on the receiving side of a conventional DBU. In the figure, 1 is a host, 2.5 is a modem, 3.4 is a dial backup device, 6 is a terminal, and 7 is a dedicated line (
4W), 7a, and 7b are each dedicated lines (2W), 8 are switched lines (4W), and 8a and 8b are each switched lines (2W).
, 9 to 12 are telephones, 20 is a control unit, 21 and 22 are ringer detectors, 23 is a switching relay, 23a is a contact of the switching relay 23, 24 is a switching relay, 24a is a contact of the switching relay 24, and 25 is a contact of the switching relay 24. Switching relay, 25a is the contact of switching relay 25, 26 is switching relay, 26a is switching relay 2
6 contact, 27 is switching relay, 27a is switching relay 27
30 is a tone generator, 31 is a tone detector, 3
2 is a control section. #jf, f)D BLJ Rule 4 RulesIf)Automatic Cutting and Cutting 4th Row

Claims (1)

[Claims] In data transmission between data communication devices (100a, 100b) using a four-wire dedicated line (7a, 7b), opposing dial backup devices (3) and ( 4) are each equipped with a tone generator (30) and a tone detector (31), and when the dedicated lines (7a, 7b) become faulty, the dial backup device (3) switches back to the initially set two lines. The own tone generator (
30), and when the dial backup device (4) detects a tone by its own tone detector (31), it sends out the output of the next set 2.
The own tone generator (
30), and when the dial backup device (3) detects a tone by the own tone detector (31), the dial backup device (4) sends back the output of the own tone generator (30). An erroneous switching prevention method characterized in that the modem is switched from the dedicated line (7a, 7b) to the two switched lines (8a, 8b) when a certain fixed period of time has elapsed.