JP2552661B2 - Line switching control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a line switching control method for switching a telephone between an external line and an internal line, and in particular, it has one external line and several internal telephones. The present invention relates to a line switching control method most suitable for a simple telephone control device.

[Conventional technology]

As a telephone control device to which a plurality of telephones are connected and which can make an outside call and an extension call, there is a telephone exchange device represented by a private branch exchange or a key telephone device.

A method of supplementing an external line or an internal line of these telephone exchange devices is, for example, by hooking off a telephone in a private branch exchange,
A method is adopted in which the telephone is connected to an outgoing line register and then the telephone is connected to an outside line or an extension line by dialing an outside line calling number or an extension number from the telephone. A method is adopted in which the telephone is connected to an outside line or an extension line by pressing the line selection button after the telephone is turned off.

[Problems to be solved by the invention]

In the line supplement method in the above conventional telephone exchange device,
The process from receiving the dial information to connecting the line is complicated, and the hardware (call register etc.) related to it is also required to be sophisticated (in the case of a private branch exchange), and the line selection means is required for the telephone. The system configuration becomes complicated and expensive (for a key telephone device). For example, the conventional line supplementing method is used for line switching control in a small system with one external line and a few telephones. You cannot do it.

The present invention proposes to solve the above problems,
It is an object of the present invention to obtain a line switching control method which is simple in control processing and can be easily configured in hardware, and which is particularly suitable for a small-scale system.

[Means for solving problems]

To achieve the above object, the present invention connects the telephone to an external line by hooking off the telephone and judges whether or not a dial signal is transmitted from the telephone to the external line by monitoring the external line, When a set time, for example 3 seconds, has passed without a signal being sent,
The connection of the telephone is switched to the extension line.

[Structure of Example]

1 and 2 are block diagrams of the first and second embodiments of the present invention, respectively. Each of the present embodiments is an example in which the telephone control device has one external line and three telephones.

In FIG. 1 and FIG. 2, 1 is a telephone control device, 21-
Reference numeral 23 is a telephone housed in the telephone control device 1 (hereinafter referred to as extension telephone), 3 is a telephone station, and 4 is a callee telephone of an outside line for communicating with the telephone control device 1.

In the telephone control device 1, 11 is an outside line, 121 to 123 are extension lines, 131 to 133 are loop monitoring units for detecting hook-off of the extension telephones 21 to 23, and 141 to 143 are extension telephones 21 to 23, respectively. A switch unit that controls switching connection between the external line 11 and the internal lines 121 to 123, 15 is a dial signal sent to the external line 11, an external line monitoring unit that monitors incoming calls from the external line, and 16 is an internal line connection confirmation sound. A signal device for generating 17 is provided between the extension lines 121 to 123 and between the traffic signal 16 and the extension lines 121 to 123
An extension call control unit 18 for controlling connection with a so-called one-chip CPU is mainly configured, and a central processing unit for collectively controlling the telephone control device 1 is provided. 181 is a central processing unit 1.
This timer is set by the program of 8 and monitors the time from the extension telephones 21 to 23 being turned off to the sending of the first digit dial.

As shown in FIG. 1, the extension telephone 21-
23 are coupled to the outside line 11 via the switch units 141 to 143, respectively, and are connected to the extension lines 121 to 123 via the switch units 141 to 143 and the loop monitoring units 131 to 133, respectively. ~ 143 is always (extension phone 21
~ 23 is on-hook) is an extension line 121-123
Facing to the side.

In addition, the extension lines 121 to 123 are connected to the extension call control unit 17, and when the extension telephones 21 to 23 desire an extension call, they receive the dialed number of the called extension, the extension call path is closed, and the extension call is made. All hardware related to extension connection such as supply of electric current is included in the extension call control unit 17, but since the hardware is not directly related to the present invention, detailed description thereof will be omitted here.

The second embodiment shown in FIG. 2 differs from the first embodiment in the following points. That is, first, the loop monitoring units 131 to 133 are inserted and connected between the extension telephones 21 to 23 and the switch units 141 to 143, and secondly, the switch units 141 to 143 are always on the outside line 11 side. The other configuration is the same as that of the first embodiment.

Although the switch parts 141 to 143 are shown as mechanical switches in FIGS. 1 and 2, it goes without saying that they can be constituted by semiconductor switch elements.

[Operation of Example]

Since the present invention relates to line switching control at the time of making a call from the extension telephones 21 to 23, the following description will be made only at the time of making a call. In addition, line connection control is an external line
11 has priority over extension lines 121 to 123.

 First, the operation of the first embodiment shown in FIG. 1 will be described.

When any extension telephone, for example, extension telephone 21 is hooked off, the DC loop is closed in the extension telephone 21. The loop monitoring unit 131 detects that the DC loop is closed in the extension telephone 21, and the central processing unit 18 reads the detection signal from the loop monitoring unit 131 to read the extension telephone 21.
Identify the hook-offs of.

When the central processing unit 18 identifies the hook-off of the extension telephone 21, it immediately controls the switch unit 141 corresponding to the extension telephone 21, switches the extension telephone 21 to the outside line 11 side, and activates the timer 181 to activate the extension telephone 21.
From the first to the transmission of the first digit dial signal is monitored.

At this time, since the extension telephone 21 is connected to the outside line 11 in the off-hook state, the telephone station 3 performs a call connection process and a dial tone (so-called dial tone) is sent from the signal device 31. Sound is sent to the extension telephone 21 through the outside line monitoring unit 15, the outside line 11, and the switch unit 141. As described above, the signal tone for confirming that the outside line 11 is connected does not need to be generated from the telephone control device 1 itself, and the dial tone from the telephone station 3 can be used as it is.

When a call is made from the extension telephone 21 to the outside telephone line 11, the first digit dial operation is performed on the extension telephone 21 within the time set by the timer 181 after off-hook, for example, within 3 seconds.

Dial the 1st digit to dial an external line from the extension 21
The dial signal sent to 11 is sent to the telephone station 3 and detected by the outside line monitoring unit 15, and the central processing unit 18 reads the dial signal detection by the outside line monitoring unit 15 and stops the activation of the timer 181. The operation of the switch unit 141 is held. As a result, all dial signals of the second and subsequent digits sent from the extension telephone 21 are sent to the telephone station 3 through the outside line 11, so that the connection processing at the telephone station 3 and the response from the telephone 4 at the other end will The extension telephone 21 can make an outside call with the telephone 4 to be called.

When making a call from the extension telephone 21 to the extension line 121,
After off-hook, wait for the set time (3 seconds) by timer 181 without dialing.

When the central processing unit 18 cannot read the dial signal detection from the outside line monitoring unit 15 within the time set by the timer 181, the switch unit 141 is controlled again at the time when the timer 181 measures the set time, and the extension telephone 21 is extended. Line 121
The switch 16 is connected to the extension line 121 and the signal line 16 is connected to the extension line 121 by controlling the extension call control unit 17.

The signal device 16 has a signal tone different from the dial tone generated by the signal device 31 of the telephone station 3, for example, a signal tone having a different tone color (including a signal tone having a different frequency) or a signal tone having a different intermittent period (the above-mentioned signal tone). When the outside line is a local line, the dial tone is usually a continuous tone, which can be understood as a signal with an infinite intermittent period.), And the signal tone sent to the extension telephone 21. Changes when the switch unit 141 switches when the set time (3 seconds) defined by the timer 181 has elapsed. That is, the extension telephone 21
When the call is sent to 121, it is sufficient to wait for the change in the signal sound heard from the receiver after the hook-off, and it is not necessary to rely on the so-called intuition.

When the extension telephone 21 dials the extension number after the signal tone changes, the dial signal sent from the extension telephone 21 is sent to the dial signal receiving unit (not shown) of the extension call control unit 17 via the extension line 121. Central processing unit
Reference numeral 18 controls a call path switch unit (not shown) of the extension call control unit 17 based on the dial information read from the extension call control unit 17, and the extension line 121 and an extension line corresponding to the dial information, for example, an extension line. Connect to the line 122.
As a result, the extension telephone 21 can make an extension call with the extension telephone 22.

Further, the present invention can be implemented without providing the signal device 16. That is, in this case, the switch unit 141
~ 143 is directed to the outside line 11 side, the dial tone generated by the signal device 31 of the central office 3 is the extension telephones 21 to 23.
When the switch units 141 to 143 are switched to the extension lines 121 to 123, the dial tone disappears. Therefore, even if such a change in signal tone (sending and stopping of signal tone) occurs, The switching from the line 11 to the extension lines 121 to 123 can be recognized.

Further, for example, when the extension telephone set 21 is already in an outside line call and the extension telephone set 22 is off-hooked, the switch unit 142 corresponding to the extension telephone set 22 is not controlled to be directed to the side of the extension line 11 (the extension line 11 is The fact that it is in use can be identified by monitoring the outside line monitoring unit 15.) Further, the timer 181 does not monitor the time. That is, the extension line 122 is connected to the extension line telephone 22 from the beginning, and this means that the signal tone from the signal device 16 is sent to the extension line telephone 22 when the extension phone 22 is off-hook (or silence when the signal device 16 is not provided). Be recognized).

Next, with respect to the second embodiment shown in FIG. 2, the operation of the part different from the first embodiment will be described.

For example, when the extension telephone 21 is turned off, the central processing unit 18 reads the extension hook of the extension telephone 21 from the loop monitor 131, activates the timer 181 and all the switch portions 142, 143 other than the switch portion 141 corresponding to the extension telephone 21. Control these switch parts 14
2,143 is switched to the extension line 122,123 side. When the extension telephone 21 dials the first digit within the time set by the timer 181, the connection between the extension line 11 and the extension telephone 21 is maintained and the call is transmitted to the outside, as in the first embodiment. Also,
If the extension telephone 21 does not dial the first digit within the time set by the timer 181, the central processing unit 18 controls the switch unit 141 to connect the extension telephone 21 to the extension 121 when the set time elapses. The switch sections 142, 143 are controlled so that the switch sections 142, 143 are turned to the outside line circuits 142, 143 again. As a result, the extension telephone 21 becomes an extension call, and the extension telephones 22 and 23
Is always available for outside calls.

〔The invention's effect〕

As described above in detail, according to the present invention, the hook-off of the telephone is used to connect the telephone to an external line having a higher priority and monitor the time from the hook-off until the first digit is dialed. If the 1st digit dial signal is not sent from the telephone, the telephone is switched to the extension line with the lower priority, and it is made known by the change in the signal tone being sent to the telephone that the line has been switched. It is possible to switch the line with extremely simple means and control, and since it is possible to recognize with a signal sound without considering the line switching, it is less likely that an operation error will occur. The invention has various advantages and its effect is extremely large.

[Brief description of drawings]

1 and 2 are block diagrams showing an embodiment of the present invention. (Main symbols) 1 ... Telephone control device 21-23 ... Extension telephone 11 ... External line 121-123 ... Extension line 141-143 ... Switch 16 ... Signal 18 ... Central processing unit 181 ... …timer.

Claims (2)

(57) [Claims] 1. A telephone control device for accommodating a plurality of telephones, an outside line and an extension line, and enabling the telephone to make a call through the outside line and between the telephones through the extension line. In the line switching control method described above, by hooking off the telephone, the telephone is connected to an external line, and whether the dial signal is transmitted from the telephone to the external line is determined by monitoring the external line, A line switching control method for switching the connection of the telephone to an extension line when a set time has elapsed without sending the dial signal. 2. A telephone control device for accommodating a plurality of telephones, an outside line and an extension line, and enabling the telephone to talk via the outside line and between the telephones via the extension line. In the line switching control method, the dial tone sent from the outside line is relayed to the telephone when the telephone is connected to the outside line, and the dial tone is relayed to the telephone when the connection of the telephone is switched to the extension line. A line switching control method for making the type of the line connected to the telephone known to the public by disabling.