JPH04326651A - Network controller for terminal equipment - Google Patents

Abstract

PURPOSE:To realize the network controller for terminal equipment in which communication is not disturbed by mis-reply of a facsimile equipment by disconnecting a device connected by a connection changeover circuit when a main controller detects it that a no ringing signal reaches itself. CONSTITUTION:Suppose that a FAX equipment 11 harmful to no ringing (NRS) communication is connected to a post-stage of a terminal equipment use controller(T-NCU) 6. The moment when a main controller 605 of the T-NCU6 detects the NRS signal and discriminates it to be addressed to its own terminal equipment, the controller 605 drives a connection changeover circuit 612. Since the FAX equipment 11 is disconnected from the T-NCU6, even when a signal similar to the FAX start signal is included in the NRS signal component, it is prevented that the FAX equipment 11 mistakes the signal to reach itself and replies it in mistake. Thus, the communication of the T-NCU is not disturbed due to mis-reply of the facsimile equipment.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a terminal network control device for an automatic data communication system using subscriber telephone lines.
In particular, devices that are harmful to no-ringing communications (such as facsimile machines) that are connected after the terminal network control device.
Concerning countermeasures against communication interference.

0002

[Prior Art] Generally, terminal network control equipment (T-NCU)
) is activated from the center side, the no-ringing trunk issues a polarity inversion signal first and a no-ringing (NRS) signal second. Then, that signal is transmitted to the facsimile (
FAX), telephones, etc. are also sent via connection lines.

0003

[Problem to be Solved by the Invention] However, the NRS signal has a signal component that is FA
A signal similar to the X activation signal may be included. For this reason, in the T-NCU mentioned above, the FAX connected to the subsequent stage of the T-NCU may mistakenly respond to the signal that came to it, and this interferes with the T-NCU's communication, making it impossible to communicate. There is a problem.

[0004] In view of the above, the present invention aims to provide a T-NCU whose communication is not interrupted by erroneous FAX responses.

[0005]

[Means for Solving the Problem] A means for solving the problem according to claim 1 of the present invention, as shown in FIGS. 1 to 4, performs data communication by making terminal calls from terminal devices 7 and 8 using a telephone line. Alternatively, in an automatic data communication system that performs data communication using the no-ringing trunk 5 when activated from the center side, when a terminal network control device is activated from the center side via the no-ringing trunk 5, a no-ringing signal is detected. A main controller 605 that determines whether the no-ringing signal is from the own terminal, and a connection switching circuit 612 that disconnects the connected device 11 when the main controller 605 determines that the no-ringing signal detected is from the own terminal. It is prepared.

[0006] Further, the problem solving means according to claim 2 of the present invention is the terminal network control device according to claim 1, which is provided with a command for setting whether or not to disconnect the devices 9 and 11 connected to the subsequent stage. Claim 1 based on the command
It drives and controls the connection switching circuit 612 described.

[0007]

[Function] In the problem solving means according to claim 1, when the terminal network control device is activated from the center side via the no-ringing trunk 5, the main control device 605 detects a no-ringing signal and automatically detects the no-ringing signal. Determine whether it is a terminal or not. When the main controller 605 detects the no-ringing signal and determines that it is the own terminal, the main controller 605 at that moment drives the connection switching circuit 612 to remove the device 11 harmful to the no-ringing communication from the terminal network controller. Separate.

Therefore, even if the no-ringing signal component contains a signal similar to the activation signal of the device 11, the device 11 will not mistakenly respond to the signal that came to it, so that the device 11 will not be mistaken. The response does not interfere with communication of the terminal network control device.

Further, according to claim 2, since the disconnection operation can be selected by a command, when the device 11 harmful to no-ringing communication is connected, the main controller 605 drives the connection switching circuit 612 to disconnect it. On the other hand, when a device 9 useful for no-ringing communication is connected, the main controller 605 switches the connection switching circuit 61
This is very convenient because it does not have to be disconnected without driving 2.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 4.

FIG. 2 shows a block diagram of a data communication system including a terminal network control device according to an embodiment of the present invention. In FIG. 2, 1 is a host computer, 2 is a center side network control unit (C-NCU), 3 is an exchange connected to the center side, 4 is an exchange connected to the terminal side, and 5 is used in a no-ringing system. 6 is a terminal network control unit (T-NCU), 7 and 8 are terminal devices such as meters and sensors, 9 is a home telephone, 11, 15
, 16 and 17 are connection lines, 12 and 13 are telephone lines, 14 is an interoffice trunk line, and 19 and 20 are interface lines between the terminal exchange 4 and the no-ringing trunk 5.

FIG. 3 also shows a block diagram of the terminal network control device. In FIG. 3, a polarity detection circuit 601, a modem 613, and a connection switching circuit 612 are connected to the telephone line 13. The polarity reversal detection circuit 601 is a circuit that detects that the no-ringing trunk 5 has reversed the polarity of the telephone line 13. Then, in the polar anti-polarity detection circuit 601,
A no-ringing signal (NRS) detection circuit 603 is connected. Further, the pole anti-polarity detection circuit 601, the NRS detection circuit 603, and the modem 613 are connected to the main control device 605. Connection switching circuit 612 is connected to off-hook detection circuit 611 and main controller 605. The off-hook detection circuit 611 detects whether the T-NCU 6 is connected to a recording terminal device 9 or a facsimile (FAX) device 11 during communication.
and a circuit for detecting whether or not the home telephone 10 is being used. Further, connected to the main controller 605 are a reset circuit 608 for resetting the main controller 605 and an oscillation circuit 609 for supplying a reference clock signal. The power supply circuit 610 uses a built-in battery to power this T-NC.
This is a circuit that supplies power to U6.

[0013] Also, terminal devices 7, 8 such as meters and sensors
are connected to the main controller 605 via interface circuits 606 and 607, respectively. Main control device 6
The number of terminal devices that can be connected to 05 depends on the use of main controller 605.

Furthermore, the FAX device 11 or the recording terminal device 9 is connected to the telephone line 13 via a connection switching circuit 612. The home telephone 10 is connected to a FAX device 11 or a recording terminal device 9.

[0015] Here, the operation of the T-NCU 6 will be explained. When a no-ringing call is received from the center side device, polarity reversal detection circuit 601 first detects polarity reversal. When a polarity reversal is detected, the main controller 60
5 switches from standby mode to no-ringing (NRS) signal detection operation mode. When the NRS detection circuit 603 detects the NRS signal, it regards it as a no-ringing incoming call and transmits a no-ringing trunk (NRTS) signal, which is a response signal from the T-NCU 6. Then, a communication link with the center side device is established, and the T-N
Data communication is started between the CU 6 and the center side device via the modem 613 in an asynchronous manner.

FIG. 3 shows an internal configuration diagram of the main control unit in the T-NCU. As shown in the figure, the main control device 605 includes a CPU 702 which is a central control unit, a timer/counter 701 which inputs a signal from a transmission circuit 609 and measures time, and a CPU 702 which is a central control unit.
a program memory 704 that commands control to T 702;
- Data memory 703 that holds rewritable data to be held in the NCU and temporary data generated internally
and an I interface with which the main controller 605 interfaces with the outside.
/O705 (including an interrupt terminal). Also,
In order to deal with communication interference with the T-NCU 6 caused by the FAX device 11 shown in FIG.
is programmed in the program memory 704 in the
A main controller 605 controls each block within the T-NCU and executes procedures.

FIG. 1 is a flowchart showing the disconnection processing procedure when a harmful FAX device is connected to the rear stage of the T-NCU, and this will be explained.

When the T-NCU 6 receives a no-ringing call from the center side device, the polar reversal detection circuit 601 first detects polar reversal. When a polar reversal is detected, a polar reversal interrupt signal is generated and the main controller 605 switches from the standby mode (step 1) to the NRS detection operating mode. Then, by operating the NRS detection circuit 603, the NRS signal transmitted from the no-ringing trunk 5 for about one second is detected (step 2). When the NRS detection circuit 603 detects the NRS signal, it confirms the time (approximately 70 msec) specified in the technical standards (step 3). Then, it is checked whether it matches the NRS number set in the main controller 605 of the T-NCU 6 (
Step 4). If they do not match, return to step 1. If they match, it is determined that it is the own terminal, and the process moves to the next step 5.

In step 5, the RAM set in the main controller 605 determines whether or not to disconnect the FAX device 11, telephone 10, etc. connected to the subsequent stage of the T-NCU 6.
Check. This RAM is set in advance by a command to 1 when a FAX device 11 harmful to no-ringing communication is connected, or to 0 when a recording terminal device 9 useful for no-ringing communication is connected. . If the command is 1, the connection switching circuit 612 is driven to disconnect the FAX device 11, telephone 10, etc. connected to the subsequent stage of the T-NCU 6 (step 6). If the command is set to 0, proceed to the next step, then confirm that the NRS signal has been interrupted, and after a certain period of time send out a no-ringing trunk (NRTS) signal, which is a response signal from the T-NCU 6 (
Step 7): Start communication.

[0020] In this way, when the FAX device 11 harmful to no-ringing communication is connected to the downstream of the T-NCU 6, the moment the main control device 605 of the T-NCU 6 detects the NRS signal and determines that it is the own terminal. The main controller 60
5 drives the connection switching circuit 612 to disconnect the FAX device 11 from the T-NCU 6, so the NRS signal component is
Even if a signal similar to the X activation signal is included, the FAX device 11 will not erroneously respond to a signal that has come to itself. Therefore, communication of the T-NCU is not disturbed due to erroneous FAX responses.

[0021] Furthermore, since the disconnection operation can be selected by a command, FAX equipment 1 which is harmful to no-ringing communication can be selected.
1 is connected, and conversely, when the recording terminal device 9 useful for no-ringing communication is connected, it is possible to not disconnect it, which is very convenient.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

[0023]

As is clear from the above description, according to claim 1 of the present invention, if a FAX that is harmful to no-ringing communication is connected after the T-NCU, the T-NC
The moment the main controller of U detects the NRS signal and determines that it is its own terminal, the main controller drives the connection switching circuit to switch to the FA.
Since X is separated from T-NCU, F is added to the NRS signal component.
Even if a signal similar to the AX activation signal is included, the FAX
There is no chance that you will mistakenly respond to a signal sent to you by mistake. Therefore, communication of the T-NCU will not be disturbed due to erroneous FAX responses.

Furthermore, according to claim 2, the disconnection operation can be selected by a command, so that when a harmful FAX is connected, it is disconnected, and conversely, when a useful recording terminal device or the like is connected, it is not disconnected. is possible and very convenient.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a procedure for disconnecting connected devices by a terminal network control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a data communication system including a terminal network control device.

FIG. 3 is a block diagram of a terminal network control device.

FIG. 4 is a block diagram of the main control device of the terminal network control device.

[Explanation of symbols]

1 Host computer 2 Center-side network control device 3 Center-side exchange 4 Terminal-side exchange 5 No-ringing trunk 6 Terminal network control devices 7, 8 Meters, sensors, etc. 9 Recording terminal equipment 10 Telephone 11 FAX equipment 601 Polarity detection circuit 603 NRS detection circuit 605 Main controller 606, 607 Interface circuit 608
Reset circuit 609 Transmission circuit 610 Power supply circuit 611 Off-hook detection circuit 612 Connection switching circuit 613 Modem 701 Timer/counter 702 CPU 703 Data memory 704 Program memory 705 I/O

Claims (2)

[Claims] [Claim 1] In an automatic data communication system that performs data communication by making a terminal call from a terminal device using a telephone line, or performs data communication using a no-ringing trunk initiated from the center side, When starting up a network control device for a terminal via a no-ringing trunk, a main control device detects a no-ringing signal and determines whether the no-ringing signal is from the own terminal, and a main control device detects a no-ringing signal and determines whether the no-ringing signal is from the own terminal; A network control device for a terminal, comprising a connection switching circuit that disconnects a connected device when it is determined that the device is connected. 2. The terminal network control device according to claim 1, further comprising a command for setting whether to disconnect a device connected to a subsequent stage, and driving the connection switching circuit according to claim 1 based on the command. A network control device for a terminal, characterized in that it controls.