JPH04126430A - Wire connection detection method for digital telephone set - Google Patents

Abstract

PURPOSE:To eliminate the need for a wire connection detection circuit by the detection of supply power and to relieve the load of the hardware by adding a message for establishing synchronization between a digital telephone set and a DSU between a telephone set function control section and a network control section of the digital telephone set. CONSTITUTION:When hook-off or the like is implemented, a telephone set function control section transfers a synchronization establishment request message between a digital telephone set and a DSU to a network control section to detect connection/ nonconnection between the digital telephone set and the DSU. When the digital telephone set confirms the establishment of synchronization between the digital telephone set and the DSU through the reception of a synchronization establishment confirmation signal INFO 4, the network control section transfers a synchronization establishment notice message to the telephone set function control section. Upon the receipt of the synchronization establishment notice message, the telephone set function control section discriminates the state to be the line connection state and uses a visual or an audible display device to display the connection state for the user and enters the user calling waiting state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wiring connection detection method for a digital telephone that uses ISDN as a transmission path.

[Conventional technology]

Conventionally, digital telephones that use ISDN as a transmission path have determined whether the wiring is connected or disconnected based on the presence or absence of phantom power supplied from a digital line termination unit (hereinafter referred to as DSU) via the wiring.

[Problem to be solved by the invention]

Digital telephones using this wiring detection method are
A power supply detection function was required for the purpose of detecting wiring connections, and digital telephones had built-in hardware components to implement this function. This part needs to electrically isolate the wiring from the control circuit inside the digital phone.
In addition, the power that can be received from the DSU via wiring is limited to 3 mW, and since this power is extremely small, the load (internal 1IIIi
Isolated switching regulators were used because they needed to have high conversion efficiency and be able to supply power to 61 circuits.

The wiring connection detection method using a switching regulator as described above requires an isolation transformer, a receiving power limiting circuit, a switching element, and a pulse generation circuit to drive the switching element in the switching regulator, and requires a large number of components and a control circuit. is not economical because it is complicated,
In addition, on the wiring between the digital telephone and the DSU, there is a disconnection of only one of the transmitting function bare wires (hereinafter referred to as T wires) or one of the receiving function pair wires (hereinafter referred to as R wires), or the T wires are connected to each other. Alternatively, if a wiring failure occurs such as a short circuit between the R wire and the cow, there is a drawback that it is erroneously determined that the wiring is connected even though communication cannot actually be performed.

The wiring connection detection method of the present invention eliminates the need for hardware components for detecting power supply for the purpose of detecting wiring connections, which was required in the past, making it more economical. The purpose is also to be able to detect.

[Means to solve the problem]

As previously mentioned, to ensure the possibility of communication on the digital telephone to DSU III wiring, it is necessary to ensure that the T and R wires are all properly connected.

In the present invention, as a method of checking whether all the T and R lines are properly connected, the CCITT Kai standard [User
A layer I synchronization establishment procedure at network interface J is used.

Therefore, the following message is newly added between the telephone function control section of the digital telephone and the network control section.

Message to request establishment of synchronization between faJ connection department - network control section - digital telephone - DSUlil Cbl network control section Live telephone function control section Message to notify the synchronization status between digital telephone and DSU Network control Upon receiving the message (a), the section enters the synchronization establishment procedure and confirms the status by sending the message (5) to the telephone function #.
Notify I4Ig department. Telephone function Iw connection section (a)
A message from the network controller requests establishment of synchronization, and a message from the network controller is received from the network controller to determine connection/non-connection.

[For production]

By using the method mentioned earlier, a digital telephone
You can confirm that the T and R wires are all connected correctly using the DSU jumper.

Further, since the wire connection detection in the present invention is realized by software, the wire connection detection circuit that detects the supplied power, which is conventionally used, is unnecessary, and the hardware can be reduced.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The first rM is a circuit configuration diagram showing an embodiment according to the present invention. l is a digital telephone and is configured as follows. The telephone function control section 1-a has a man-machine interface control function and an interface function with the network control section 1-b. The network control unit t-b has a CCITT standard [user-network interface] protocol flJwJII function and an interface function with the telephone function control unit 1-a.

The driver 1-c converts the transmission signal into an AMI signal waveform and sends it to the wiring via the isolation transformer 1-e. The receiver l-d converts the AM2 signal received from the wiring via the insulating transformer l-f into a signal that can be recognized by the network control unit 1-b and transfers the signal. 2 is an interface cable that transfers bidirectional signals between the digital telephone and the DSU, and a T line 2-a that transmits signals in the direction of the digital telephone and the DSU.
and both elbows of the R line 2-b which transmits signals from the DSU to the digital telephone. 3 is DSU and T
The line transformer 3-a receives the signal sent from the digital telephone, and the R-line transformer 3-b transmits the signal to the digital telephone. The power supply unit 3-c outputs a nominal voltage of 40V, and a negative potential is connected to the wiring-side center tap of the R-line transformer 3-b of the DSU and the wiring-side center tap of the T-line transformer 3-a, respectively. . T line 2-a and R
A phantom power supply circuit from the DSU to the digital telephone by the power supply section 3-c is constructed using the bimorphism of the line 2-b.

The conventional connection detection method requires a voltage detector 1-g as shown in FIG. 2 in order to detect the power supplied to the phantom from this DSU. Figure 3 shows a wiring fault that is incorrectly determined to be a connection using the conventional method. Figure 3(a) shows a disconnection of one of the T wires and one of the R wires, and Figure 3(b)
) is a short circuit between the T wire and the R wire. If a wiring fault exists as described above, the telephone function control unit that receives an activation request caused by the user performing an operation intended to make a call, such as off-hook, enters the state of waiting for the user's call operation. Displays that it is possible to make a call to.

FIG. 4 is a diagram showing an example of the connection/non-connection detection procedure according to the present invention, and FIG. 4(a) shows the detection procedure when both the T line and the R line are normally connected. When the user performs an off-hook operation, for example, activation of the telephone function Ill1I1 is requested. Upon receiving this request, the telephone system function section sends the digital telephone to the network control section in order to detect connection/disconnection between the digital telephone and the DSU.
Transfers synchronization establishment request messages between DSUs. The network control unit sends an activation request signal IN to the DSU via the pulse driver in order to activate the synchronization procedure between the digital telephone and the DSU.
Send the FOI and start the timer at the same time. If the T line is normally connected, the DSU receives an activation request signal INFOI from the digital telephone and transmits a frame synchronization signal INFO2 in response to the activation request signal INFOI to the digital telephone. At this time, if the R line is connected normally, the frame synchronization signal I
The digital telephone receives NFO2, and synchronization from the DSU to the digital telephone is established. Frame synchronization signal I
Upon receiving NFO2, the digital packing machine immediately transmits a synchronization establishment signal INFO3, which is received by the DSU, thereby establishing synchronization in the direction from the digital telephone to the DSU. DSU that received synchronization establishment signal INFO3 and completed startup
transmits a synchronization establishment confirmation signal INFO4. By receiving the synchronization establishment confirmation signal INFO4, the digital telephone confirms that synchronization between the digital telephone and the DSU has been established. After confirming the establishment of synchronization between the digital telephone and the DSU, the network control section transfers a synchronization establishment notification message to the telephone function control section. (These synchronization procedures are performed before the previously started timer times out.) The telephone function control section determines that the wiring is connected by receiving the synchronization establishment notification message, and indicates whether the wire is connected by the visual or audible indicator. It displays to the user that it is connected and waits for the user to make a call. A normal call procedure is activated by the user's call operation while waiting for the user call operation. FIG. 4(b) shows the detection procedure when the wiring is not connected. Digital telephone-D sent by the telephone function lll1lI section in response to a startup request from the user.
The network control unit that receives the synchronization establishment request message between SUs transmits an activation request signal INFOI and activates a timer. Since the wiring is not connected, the digital telephone does not receive the frame synchronization signal INFO2 and issues INFO! The timer set at the sender when sending out times out.

The network control unit that detects the timeout transfers a synchronization error notification message to the telephone function control unit. The telephone function control unit that receives this synchronization error notification message determines that the wiring is disconnected, and displays the disconnected status to the user using a visual or audible display.

〔Effect of the invention〕

As described in detail above, the present invention provides a digital telephone-D interface between the telephone function control section of the digital telephone and the network control section.
The simple method of adding messages for establishing synchronization between SUs has the following effects.

Wiring connections can be detected without using conventionally required hardware components, making it possible to save money. In addition, it is now possible to detect some wiring faults that were incorrectly determined to be connections using conventional methods, and it is now possible to confirm that all T and R wires are properly connected, thereby confirming the possibility of communication on the wiring. I can guarantee it.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a circuit configuration for implementing the detection method according to the present invention, Fig. 2 is a configuration diagram of a conventional circuit implementing the detection method using power detection components, and Fig. 3 is a diagram showing the drawbacks of the conventional detection method. FIG. 4 is a diagram explaining the connection/disconnection detection procedure according to the present invention, and FIG. 4(a) is the wiring connection state detection procedure. FIG. 4(b) is the wiring disconnection state. An example of the detection procedure is shown below. ! Figure 2 Telephone gu = 1 := Now DSU Voltage detector Figure 3 (b) Power supply device 2-t'- Telephone function control unit Network control unit SU Figure 4 (a) Telephone Figure 4 (b) Procedure correction Type (method) % formula % 1. Indication of the case Japanese Patent Application No. 2-246250 Z Name of the invention Method for detecting wiring connections for digital telephones 3 Person making the amendment Relationship to the case Patent applicant Representative applicant Specification 轻 -- I

Claims (1)

[Claims] In a digital telephone that uses ISDN as a transmission path, there is a system between a network control section that controls layers 1 to 3 and a telephone function control section that controls the state of the telephone according to signals from the network control section and user operations. , a message requesting the activation of the frame synchronization establishment procedure in layer 1 and a message notifying the synchronization state after the activation of the frame synchronization establishment procedure are provided, and the network controller is configured to perform a counting operation in conjunction with the activation of the frame synchronization establishment procedure. The network control unit receives a message requesting activation of the frame synchronization establishment procedure from the telephone function control unit, activates the frame synchronization establishment on the rope side, and starts the frame synchronization establishment procedure for a predetermined time of the timer. If synchronization establishment is confirmed within the specified time period, a synchronization establishment notification is sent to the telephone function control unit, and if synchronization establishment is not confirmed within the predetermined time of the timer, a synchronization error notification is sent to the telephone function control unit. , the synchronization establishment notification/
A synchronization error notification causes the phone function control unit to connect/reset the wiring.
A method for detecting wiring connection of a digital telephone, characterized by determining non-connection.