JPH01200865A - Personal computer communication adapter - Google Patents

Abstract

PURPOSE:To prevent a busy condition from being continued over a long period for a communication by detecting an interruption in the middle of the communication when a third party executes an interruption, suspending the communication, and calling a third party. CONSTITUTION:When a calling side 31 and an incoming side 32 execute the communication through an exchange 34 and an interruption person 33 telephones to the calling side 31, the exchange 34 sends an interrupting signal to the calling side 31. When the communication adapter of the calling side 31 detects it by an interrupting signal detecting part 5, a communication stopping request command is sent through a protocol control part 2, etc., to a line. When the communication adapter of the incoming side 32 receives the communication stopping request command, respective kinds of circuits are operated, to transit to a suspended condition, a ringing tone is generated from an alarm sound generating part 7, and when an operator takes up a handset 8, the line is switched to the set 8, and a line switching pulse is sent from a pulse sending part 6. When the exchange receives it, the route of a telephone line is switched between the calling side 31 and interrupting person 33.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is used for communication between personal computers or communication between a personal computer and another information processing device using a telephone line. In particular, it relates to a personal computer communication adapter that controls communication between a personal computer and a telephone line.

〔overview〕

The present invention prevents communication errors caused by interrupt signals on the telephone line by allowing interrupts from third parties in a personal computer communication adapter that controls communication between a personal computer and a telephone line, and further improves communication This allows you to interrupt the call and talk to a third party.

[Conventional technology]

2. Description of the Related Art Telephone lines are used for communication between personal computers or for communication between personal computers and other information processing devices, such as so-called "personal computer communication." In that case, a personal computer communication adapter is used to connect the personal computer and the telephone line. Personal computer communication adapters include those that are built into the personal computer and those that are connected to the outside.

[Problem that the invention seeks to solve]

However, instead of using a telephone line exclusively for a personal computer, it is common to use a single telephone line by switching to a telephone. In this case, a problem arises if the telephone line is subscribed to an interrupt service (NTT call waiting service). In such services, when a third party calls, the exchange sends an audible interrupt signal to the telephone line. There is no problem if this interrupt signal occurs while the operator is on the phone, but if a personal computer communication adapter is connected to this line for communication, not only will the interrupt not be detected, but a communication error will occur. There was a drawback. In addition, since it is not possible to accept interruptions from third parties, third parties cannot make calls, and even if there is an important message, there is a drawback that the call cannot be made.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a personal computer communication adapter that can handle an interruption when a third party interrupts the telephone line in use. do.

[Means for solving problems]

The personal computer communication adapter of the present invention is characterized by comprising means for detecting an interrupt signal on a telephone line generated by a switchboard due to a call from a third party, and means for displaying the detection output of this means to an operator. shall be.

Furthermore, this communication adapter includes means for interrupting the communication based on the detection output of the detecting means, and means for sending a signal to the exchange for switching the telephone line to the interrupting line.
It is desirable to have means for restarting communication after the call with the line on the interrupting side ends. The means for interrupting communication includes means for requesting the other party to interrupt the communication, and means for interrupting the communication when the other party requests interruption, and the means for resuming communication includes restarting the communication. It is desirable to include means for requesting a communication, and means for detecting a restart request from the other party and restarting communication.

[For production]

The personal computer communication adapter of the present invention can interrupt communication to allow an operator to talk on the phone when there is an interruption from a third party, and can also prevent communication errors caused by interruption signals. Although the call can be switched manually by the operator, it is preferable to switch the call automatically.

〔Example〕

FIG. 1 is a block diagram of a personal computer communication adapter according to an embodiment of the present invention. In this embodiment, the present invention is implemented with a communication adapter of the communication system recommended by the Ministry of Posts and Telecommunications, and is compatible with the NTT call waiting service.

This communication adapter is connected between the R8232C interface 1 and the telephone line 9, and includes communication control means for controlling communication between them, that is, a protocol control section 2, a network control section 3, a V27ter modem 4, and a pulse transmission section. 6. This communication adapter further includes an interrupt detector 5 that detects an interrupt signal on the telephone line generated by the exchange due to a call from a third party, and an alarm generator that displays the detection output of the interrupt detector 5 to the operator. 7, the protocol control unit 2 includes means for interrupting communication based on the output of the interrupt detection unit 5, means for sending a signal to the exchange for switching the telephone line to the line on the interrupt side, and a line on the interrupt side. means for resuming communication after the call with the user ends.

FIG. 2 is a block diagram showing details of the protocol control section 2. As shown in FIG.

The protocol control section 2 includes a session control section 10, a transport control section 11, a network control section 12, a link control section 13, a half-duplex control section 14, a V27ter physical control section 15, and a suspend/resume control section 16. The session control section 10 , network control section 12 , link control section 13 and half-duplex control section 14 are connected to a suspend/resume control section 16 .

FIG. 3 is a diagram for explaining the operation of the embodiment, and shows the connection state of the communication network.

First, it is assumed that the calling side 31 and the called side 32 are communicating via the exchange 34. In this state, when the third party interrupter 33 makes a call to the calling party 31, the exchange 34
sends an interrupt signal to the calling side 31.

Here, for the sake of explanation, a distinction will be made between the calling side 31 and the called side 32, but the following operations are the same even if the originating and receiving calls are switched. The interrupt signal sent from the exchange 34 to the calling side 31 is a 400 Hz tone signal in the case of this embodiment, and a signal that is repeatedly on for 0.25 seconds and off for 0.25 seconds is sent for 1 second. , pause for 3 seconds, and repeat. This signal is shown in FIG. When the communication adapter on the calling side 31 detects an interrupt signal in the interrupt signal detection section 5, it notifies the protocol control section 2. When the protocol control unit 2 receives the notification of the detection of the interrupt signal, the suspend/resume control unit 16 requests the network control unit 12 to suspend. In response to this, the network control unit 12
A communication suspension request command is sent to the line via the link control unit 13, half-duplex control unit 14, and V27ter physical control unit 15.

In the protocol of the communication method recommended by the Ministry of Posts and Telecommunications, commands and responses for requesting communication suspension, acknowledgment of communication suspension, and refusal of communication suspension are defined by the format of the block header of the network layer. This is shown in FIG. In this figure, M is the more data bit and Q is the qualifier bit.
The bit F indicates a communication suspension request bit, A indicates a communication suspension approval bit, and R indicates a communication suspension refusal bit.

When the communication adapter on the called side 32 receives the communication suspension request command, the network control unit 12 detects this, notifies the suspend/resume control unit 16 of suspension acceptance, and at the same time sends a communication suspension acknowledgment response to the line. Send. The suspend/resume control section 16 monitors the state of the half-duplex control section 14, waits for completion of transmission of the communication suspension acknowledgment response, and then transitions to the suspend state. In the suspended state, the link control unit 13 monitors received frames. In the communication adapter of the calling side 31, when the network control unit 12 receives the communication suspension acknowledgment response, it notifies the suspend/resume control unit 16 of the end of suspension. As a result, the suspend/resume control unit 16 transitions to the suspend state and instructs the network control unit 3 to wait for the handset 8 to go off-hook. At the same time, the alarm sound generator 7 generates a ringing sound to call the operator.

When the operator picks up the handset 8, the network control unit 3 switches the line from the v27ter modem 4 to the handset 8.

Upon receiving the notification of line switching from the network control unit 3, the suspend/resume control unit 16 stops the alarm sound, and then causes the pulse sending unit 6 to disconnect the line for about 1 second and send out a line switching pulse.

When the exchange 34 receives the above line switching pulse, it switches the connection route of the telephone line between the calling party 31 and the interrupter 33. Through the above operations, the calling party 31 and the interrupting party 33
can make calls.

When the calling party 31 and the interrupter 33 finish their conversation and put down the handset 8 of the calling party 31, the network control unit 3 connects the line to V27t.
er modem 4 side, and notifies the protocol control unit 2 of the end of the call. When the suspend/resume controller 16 receives the notification of the end of the call, the pulse transmitter 6 transmits a line switching pulse. When the interrupter 33 hangs up or receives a line switching pulse from the calling side 31, the exchange 34 reroutes the telephone line between the calling side 31 and the called side 32. Subsequently, the suspend/resume control section 16 of the calling side 31 instructs the link control section 13 to send an RR command.

In response to this, the link control unit 13 sends an RR command with P=1 to the line.

In the communication adapter of the called side 32, the link control unit 13
When receiving an RR command with F=1, it sends an RR response with F=1 to the line. At the same time, the suspend/resume control unit 16 notifies the suspend/resume controller 16 of the suspension.

The suspend/resume control unit 16 cancels the suspended state.

In the communication adapter of the calling side 31, the link control unit 13
When an RR response of =1 is received, a resume completion notification is sent to the suspend/resume control unit 16, and the suspended state is released.

Communication is restarted through the above steps.

Here, the link layer RR command, response format and protocol are the link layer of CCITT Recommendation X25.
Follow level protocols.

Furthermore, it is equipped with a timer to prevent calls from continuing for a long time when the operator is absent on the calling side, and is configured to automatically restart communication if the operator does not pick up the handset within a certain period of time. You can also.

In addition, a timer is provided to prevent the called side from being in a suspended state unnecessarily, and if the suspended state continues for a long time,
It is also possible to configure the line to be automatically opened.

〔Effect of the invention〕

As explained above, in the personal computer communication adapter of the present invention, if there is an interruption from a third party during communication, it is possible to detect it, interrupt the communication, and talk to the third party. Furthermore, if restart control is provided, communication can be resumed after the call ends.

This has the effect of preventing communication errors caused by interrupt signals, and also preventing the communication from being in a busy state for a long time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a personal computer communication adapter according to an embodiment of the present invention. FIG. 2 is a block diagram showing details of the protocol control section. FIG. 3 is a diagram showing the connection state of a communication network. FIG. 4 is a diagram showing the format of an interrupt signal. FIG. 5 is a diagram showing the format of a network block header. 1... R3232C interface, 2... Protocol control unit, 3... Network control unit, 4... C27ter
Modem, 5... interrupt detection section, 6... pulse sending section,
7... Alarm generating section, 8... Handset, 9...
...Telephone line, IO...Session control unit, 11...
- Transport control unit, 12... Network control unit, 13... Link control unit, 14... Half-duplex control unit, 15... v27ter physical control unit, 16...
- Suspend/resume control unit, 31... calling side,
32... Called party, 33... Interrupter, 34... Exchange.

Claims (1)

[Scope of Claims] 1. In a personal computer communication adapter equipped with a communication control means for controlling communication between a personal computer and a telephone line, an interrupt signal on the telephone line generated by a switch due to a call from a third party is provided. 1. A personal computer communication adapter comprising: a means for detecting; and a means for displaying a detection output of the means to an operator.