JPS6317267B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control system for preventing a high level signal from being sent to an interrupt extension line during an interrupt connection in a private branch exchange. At the private branch exchange,
When a call is received from the central office line to the central office line trunk, the operator of the relay stand in the case of the relay stand system, or the specified extension (hereinafter referred to as the operator) in the case of the distributed relay stand system, will be notified of the incoming call from the central office line through a visible and audible display. , the operator responds to the terminating station line by operating the relay stand or extension telephone. Next, perform an operation to transfer the responding central office line to the target extension.

In the case of the distributed relay system, the handler makes a so-called callback transfer connection and connects the office line and the forwarded extension, but if the forwarded extension is busy, the handler connects the called Encounter while talking on an extension line.
In this case, in order to quickly accomplish the purpose of the incoming call on the central office line, and to improve the service by minimizing the holding time of the central office line, the operator can interrupt the incoming call to receive a busy call. This system forcibly interrupts the call on the called extension and notifies the busy called extension that there is an incoming call from the central office line, prompting the call to be terminated early.

As described above, the interrupt connection function in a private branch exchange is a basic and essential function. When an interrupt connection is made to a busy called extension that is receiving a signal at an extremely high level compared to the normal call audio level such as the ringer, the earpiece of the operator's handset suddenly becomes louder than human hearing. An unbearably loud sound will be emitted, which is not a desirable situation in terms of health and safety.

Furthermore, the above-described problem is exactly the same in the relay stand system, with the only difference being that the trunk involved is, for example, a seat device, rather than a callback trunk.

As a solution to the above problem, for example, in a distributed relay system, a method shown in the relay system diagram in FIG. 1 has been conventionally adopted for this type of interrupt connection.

A conventional example will be explained below with reference to FIG. In FIG. 1, EXTA and EXTB are extension lines, SW is a switch, COT is a central office line trunk, CBT is a callback trunk, HWT is a howler trunk, and CO is a central office line.

The extension EXTA that responded to the incoming call from the central office line CO is the central office line.
When you know the extension of the forwarding destination during a call with the CO and send a specific signal (for example, a hooking signal), the office line trunk COT identifies the specific signal and relays it.
Activates CN, holds the central office line CO, and connects the call back trunk CBT with the contact cn of the relevant relay CN.
to capture.

A dial tone (so-called dial tone) is sent from the captured call back trunk CBT, and after confirming the dial tone, the extension EXTA calls the called party's extension EXTB, which is the transfer destination, to call the called party's extension EXTB. When the extension number is dialed, the callback trunk CBT and the called party's extension EXTB are connected.

Now, if the called party's extension EXTB is in a state where the extension telephone is off the hook, a howler tone is emitted to notify the off-hook state in order to prevent the common trunk (e.g. calling register) from being on hold for a long time. Since the outgoing Howler trunk HWT is connected to the called party's extension EXTB and the called party's extension EXTB is busy, the calling party's extension is
EXTA is encountered while the called extension is busy, and the relay OF operates in the callback trunk CBT, and its contact
of the above calling party extension EXTA and called party extension
A resistor R for attenuating calls is placed on the interrupt call path between EXTB and EXTB.
Preparations are made for insertion.

Also, a busy tone is sent to the calling party's extension EXTA from the callback trunk CBT, and the calling party's extension EXTA listens to the busy tone and returns the called party's extension.
EXTB knows that it is busy, but the calling extension
EXTB busy connection status, i.e. the above calling party extension
Are you on a call with someone other than EXTA, are you disconnected from the handset and connected to the Howler trunk HWT, or are you connected to a ringing trunk (not shown in Figure 1) while calling from a caller extension other than EXTA? It is not possible to determine whether there are any.

From this state, the calling party's extension EXTA starts an operation for making an interrupt connection to the busy called party's extension EXTB.

That is, when the calling party's extension EXTA dials a predetermined specific number (for example, "2") for interrupt connection, the callback trunk CBT counts and accumulates the dialing signal from the specific number and returns the dialing signal to the calling party's extension. It determines the interrupt connection request from EXTA, operates the relay IK of the callback trunk CBT, and closes the contact ik, thereby connecting the calling party's extension EXTA and the called party's extension EXTB. Caller extension EXTA - central office trunk COT contact cn
(Make side) - Call back trunk CBT speech attenuation resistor R - Contact of (Make side) - Contact ik - Called party's extension EXTB" to complete the interrupt connection.

In this case, the called party's extension EXTB is connected to the Haulah trunk HWT and is receiving the Haulah tone, so the calling party's extension EXTB, which has made an interrupt connection to the called party's extension EXTB, also has the "Haulah trunk HWT" −
Point A - Call back trunk CBT contact ik - Contact of (make side) - Call attenuation resistor R - Office line trunk COT contact cn (make side) - Caller's extension EXTA
A howler sound is transmitted along the route. That is, by inserting a call attenuation resistor R into the interrupt call path only when an interrupt connection is made, the level of a signal such as howler sound whose level is extremely high compared to the call voice level is attenuated, and the caller's extension is The level of howling sounds etc. sent to EXTA is suppressed within a range that does not cause discomfort.

However, according to this conventional method, when an interrupt connection is made to a busy extension during a normal call, the conversation between the calling party's extension and the called party's extension is also attenuated. It is not easy to select an appropriate resistance value for the call attenuation resistor R because there is a risk that it will not be possible to ensure a sufficient level of interrupting calls.

Furthermore, it is uneconomical because it is necessary to provide a relay OF for each callback trunk CBT for inserting the speech attenuation resistor R into the interrupt communication path only when an interrupt connection is made.

The present invention has been made in order to solve the above-mentioned conventional problems, and when an interrupt connection is made to an extension that is currently talking, it is possible to interrupt the call between the calling party and the called party. If the call level is sufficient and a high-level signal such as a howler tone or ring tone is being sent to the called party (interrupted extension), the high-level signal is transmitted to the calling party (interrupted extension). The purpose of the present invention is to provide a control method for interrupt connections that can prevent calls from being sent to (extension lines).

To achieve this objective, the present invention focuses on the fact that if the type of trunk connected to the interrupted extension can be identified, an interruption connection can be made only to the extension that is currently talking, and uses a high-level signal such as a howler trunk. A storage device is provided for each trunk to be sent to store the extensions connected to the trunk, and when an interrupt connection is made, the contents of the storage device are referred to for the extension to be interrupted, and it is determined whether or not to accept an interrupt call. The system is designed to prevent high-level signals from being sent to the calling party.

An embodiment of the present invention will be described below with reference to FIG.

Figure 2 shows an example in which the present invention is implemented in a private branch exchange using stored program electronic switching. In Figure 2, EXTA and EXTB are extension lines, SW is a switch, COT is a central trunk, and CBT is a call back. trunk, HWT is a howler trunk, RGT is a ringing trunk, CO is a central office line, CC is a common control circuit, MEM is a storage device, and BUS is a bus line.

The functions of the switch SW, central office trunk COT, call back trunk CBT, and howler trunk HWT are the same as in the conventional example, and the ringing trunk RGT is used to send a ring tone to the calling extension (called extension). This is the trunk.

The storage device MEM is a device that stores the status of the extension or information and status from the various trunks, and in the present invention, stores the connection status of high-level signal trunks such as the Haulah trunk HWT and the ringing trunk RGT to the extension. parts are involved.

The common control circuit CC connects the various trunks, switch SW, and storage device through the bus line BUS.
It exchanges information with the MEM, processes it, and sends various control signals.

The extension EXTA that responded to the incoming call from the central office line CO is the central office line.
When an operation is performed to call extension EXTB with CO on hold, a so-called callback connection is made via callback trunk CBT, and if the above extension EXTB is busy with an extension other than the above extension EXTA, the above extension EXTA becomes the called extension. The connection up to the point where the inside is encountered is the same as the connection explained in the conventional example.

After the above callback connection is made, the calling extension EXTA and the called extension EXTB, which is connected to other extensions or various trunks and are in a busy state.
The communication path for interrupt connection between the caller and the caller, i.e., the route of "calling party extension EXTA - central office trunk COT contact cn (making side) - call back trunk CBT contact ik - busy called extension EXTB" is prepared, but the relay IK of the callback trunk CBT is not yet activated and its contact ik is in a conductive state (closed state).
, so no interrupt connection is made yet.

At this time, the extension number of the called party's extension EXTB is stored in the call back trunk CBT. The calling extension encountered while the called extension is talking in this state.
When EXTA dials a specific number (for example, "2") for interrupt connection, the dial signal of the specific number is received by the callback trunk CBT,
The callback trunk CBT forms the interrupt connection route by detecting the occurrence of an interrupt connection request, operating the relay IK, and closing its contact ik. Before operating, a test is performed to see whether the interrupted extension line EXTB is connected to a trunk outputting a high level signal, for example, in this embodiment, the howler trunk HWT or the ringing trunk RGT.
That is, when connecting an extension to a trunk that outputs a high-level signal, the extension number of the extension is stored in the storage device MEM for each trunk that outputs the high-level signal by the control operation of the common control circuit CC. It is controlled so that

Now, assuming that the interrupted extension EXTB, which has undergone an interrupt connection operation to the calling party's extension EXTA, is already connected to, for example, the Howler trunk HWT and is in a busy state, the above-mentioned Howler trunk HWT in the above-mentioned storage device MEM is The extension number of the extension to be interrupted, EXTB, is stored in the part (address) corresponding to .
Also, assuming that the ringing trunk RGT is not connected to any extension, the above storage device
No extension number is stored in the portion (address) of the MEM that corresponds to the ringing trunk RGT.

In this state, when the calling party extension EXTA performs the interrupt operation described above, the extension number of the called extension EXTB stored in the callback trunk CBT at the time of callback connection is transferred to the common control circuit.
The CC reads through the bus line BUS, and sequentially compares the contents of the extension number storage portion corresponding to the howler trunk HWT and ringing trunk RGT in the storage device MEM with the extension number of the extension EXTB read above.

Now, the Howler trunk in the above storage device MEM
The extension number storage part corresponding to HWT is the extension number above.
Since the extension number of EXTB is stored, the common control circuit CC detects a match between the read-in extension number and the contents of the extension number storage section when checking the extension number storage section. By detecting this coincidence, the common control circuit CC identifies that the interrupted extension EXTB is connected to the howler trunk HWT, and maintains the relay IK of the callback trunk CBT inactive. This prevents the route for said interrupt connection from being closed, thus prohibiting an interrupt connection from calling extension EXTA to called extension EXTB, and calling extension EXTA has a high level of Howler sound is not transmitted.

Also, the interrupted extension EXTB is a Haula trunk.
If the storage device is not connected to the HWT or the ringing trunk RGT and is busy with a normal call,
The extension number of the interrupted extension EXTB is not stored in any of the extension number storage portions of the MEM corresponding to the above-mentioned howler trunk HWT and ringing trunk RGT. Therefore, no match is detected in the matching operation in the common control circuit CC, and as a result, the common control circuit CC
It identifies that the EXTB is not connected to the trunk with the high-level signal sound (howler trunk HWT and ringing trunk RGT), and sends the relay IK operation instruction control signal from the common control circuit CC to the callback trunk CBT on the bus line. Send through BUS.

In the callback trunk CBT, relay IK is operated by this operation instruction control signal, and by closing its contact ik, the route for the above-mentioned interrupt connection is completed, and the calling extension EXTA interrupts the interrupted extension EXTB. Connected.

As explained in detail above, the present invention stores the extension numbers of extensions connected to trunks that output high-level signals for each trunk that outputs high-level signals, and stores the extension numbers of extensions connected to trunks that output high-level signals, and According to the present invention, an interrupt connection is prohibited for an extension connected to a trunk that outputs a level signal. Not only will you never receive a call, but if you make an interrupt connection to an extension that is currently making a normal call, there is no need to attenuate the call level as in the conventional case, so you can receive a clear interrupt call. Moreover, there is no need for a resistor for attenuating calls and a relay for electrically inserting the resistor as in the past.

As described above, according to the present invention, it is possible to improve service in terms of operation and provide an inexpensive private branch exchange, and the present invention has extremely large effects.

Although the above embodiments have been described using an example in which an interrupt connection occurs in conjunction with a so-called callback connection, the present invention is applicable not only to the embodiments but also to any type of interrupt connection. It goes without saying that this can be done.

Further, the present invention can be implemented even in exchanges other than those using the stored program electronic exchange system.

[Brief explanation of the drawing]

FIG. 1 is a relay system diagram explaining a conventional interrupt connection system, and FIG. 2 is a relay system diagram showing an embodiment of the present invention. (Main symbols), EXTA, EXTB, ...extension,
COT...Central line trunk, CBT...Callback trunk, HWT...Hauler trunk, CC...
Common control circuit, MEM...storage device.

Claims (1)

[Claims] 1. In a private branch exchange that has an interrupt connection function in which a caller encountered while the called extension is talking is forcibly connected to the called extension, the voice level of the call is
Each trunk that generates an extremely high level signal is equipped with a storage device that stores the extension connected to that trunk, and when performing an interrupt connection operation, the contents of the storage device are referred to for the extension to be interrupted, and the called A system for preventing transmission of a high level signal at the time of interrupt connection, characterized in that the interrupt connection to the called extension is prohibited when the extension is stored in the storage device.