JPS6326945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telemeter system using a telephone line for automatic meter reading of water, gas, electricity, etc. The present invention relates to a network control device for a center of a telemeter system that performs data transmission without causing any hindrance.

Small amounts of data scattered over a wide area can be collected from a master station to a child station, such as automatic meter readings for water, gas, and electricity consumption, TV audience ratings surveys, and vending machine usage surveys. The most effective method for simple data collection by sequentially activating stations is to use general subscriber telephone lines as is and use the time when no calls are being made to transmit data. ing. In addition, its application fields are very wide, and it is expected that it will become widespread in the future.

When transmitting data using a subscriber telephone line in this way, if you make a normal connection, the bell of the telephone of the terminal connected to the same line will ring, and in the case of data transmission such as automatic meter reading, It doesn't work.

Therefore, the key point is how to switch between a connection that rings the telephone bell for normal calls and a connection that does not ring the telephone bell during data transmission.

That is, the problem is how to realize a no-ringing connection that does not ring a telephone bell only during data transmission by using the existing telephone exchange network that has a connection form for telephones as is.

In addition, when a huge number of terminal devices are installed in a wide area like this system, the entire system can be centrally tested to discover faulty parts at an early stage. It is necessary to clarify the demarcation of responsibilities between the users and the users.

In any case, there is a need for efficient remote testing means at the center that can detect system failures without having to visit the terminal equipment directly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a center network control device that solves these problems and is the core of a polling system and isolation test means for realizing a telemeter system.

Next, the principle and configuration of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a no-ringing system using a general subscriber telephone line according to the present invention.

In the figure, 1 is a computer (CPU), 2 is a center network control unit (C-NCU) according to the present invention,
3 is the originating station connected to the center side; 4 is the terminating station connected to the terminal side; 5 is a special trunk added to the exchange of the terminating station in an actual no-ringing system, that is, a no-ringing trunk (NRT);
6 is a terminal network control unit (TNR-NCU), 7 is an information source such as a meter, and 8 is a subscriber telephone.

11 is a connection line, 12 is a center side telephone line, 13
is an interoffice trunk line, and 14, 15, and 16 are exchange 4 and
NRT5 interface line, 17 is subscriber telephone line,
18 is a connection line between telephone 8 and TNR-NCU 6, 1
9 is a meter cable, etc.

A computer (CPU) 1 is a data collection device that has the function of controlling a center network control device 2, and a special trunk 5 is attached to a receiving station 4.
This is a device for a new service that has a no-ringing connection function for terminal-side devices, acting as a called side for center-side devices and a calling side for terminal-side devices.

The terminal network control unit (TNR-NCU) 6 has a no-ringing terminating network control function that receives an activation signal from the nor-ring trunk (NRT) 5 that has received a no-ring connection command from the center network control unit 2; It has a data modulation/demodulation function and a meter selection/activation function, and normally operates using the office power supply via the subscriber telephone line 17.

The information source 7 indicates a meter capable of transmitting data, such as an electronic meter.

The telephone set 8 and subscriber telephone line 17 are already installed.

Furthermore, the center network control device (C-
NCU) 2 as well as special trunk (NRT) 5
This device has the functions of transmitting dial information necessary for connecting the terminal network control unit (TNR-NCU) 6, transmitting and receiving various control signals, and data modulation/demodulation functions.

Next, the operation sequence of the entire system will be explained with reference to FIGS. 2a to 2o, focusing on the center network control device which is the core of the system.

First, the center network control unit (C-NCU) 2
Meter reading is started based on the instructions from the computer (CPU) 1, and the same conditions as for making a telephone call are created (a in the figure).

The originating station 3 detects this and sends back a dial tone (DT) as a first dial request signal (b in the figure). Center network control unit (C-NCU) 2
detects this dial tone (DT) or
Alternatively, the dial sending timing is set to a certain period of time after the loop is closed.

When the C-NCU 2 receives the dial information of a special trunk that is a hidden number, ie, a no-ringing trunk (NRT) 5, from the CPU 1, it converts it into a first dial signal and transmits it, and also transmits a no-ringing trunk control signal (NRTS). do.

The originating station 3 transmits the dial information to the ICT (Incoming Trunk) of the terminating station 4 through the inter-office trunk line 13,
Special trunk (NRT) due to switching operation of terminating station 4
5 is selected and the special trunk (NRT) 5 responds. In this case, if the call is busy, a visit tone is sent from the receiving station 4 to the center. Now C-NCU2
and the special trunk 5 is connected (c to d in the figure).

Next, the special trunk (NRT) 5 is connected to the C-
A genuine C-NCU2 that has determined the presence or absence of a no-ringing trunk control signal (NRTS) from the NCU2.
It determines whether the call is from someone else or not, and sends a message such as NU Talk if the call is received by mistake. When the no-ringing trunk control signal (NRTS) is received, a second dial request signal (SDR) is sent to the C-NCU 2 (e in the figure).

After receiving the second dial request signal (SDR), the C-NCU 2 stops sending out the no-ringing trunk control signal (NRTS) and waits for the SDR from the special trunk (NRT) 5 to stop (f in the figure). After confirming that the SDR has stopped, C-NCU2:
It converts the second dial information received from the CPU 1 as a subscriber number into a second dial signal and sends it out, and also sends a no-ringing trunk control signal (NRTS) to the special trunk 5 (g in the figure).
From i).

The destination station 4 performs a switching operation based on this signal, and after connection, a special trunk 5 sends an activation signal to the terminal network control unit (TNR-NCU) 6 by inverting the polarity and using a special alternating current ringing signal (NRS). and terminal network control equipment (TNR-
Wait for a response from NCU) 6. At this time, the terminating station does not send out a 16Hz bell signal, so a no-ringing connection is established in which the telephone bell does not ring. In this case, if the subscriber line is busy, a visit tone is sent to the center from the special trunk (NRT).

When the special trunk 5 detects a response from the terminal network control unit (TNR-NCU) 6, it sends a polarity inversion signal back to the center network control unit (C-NCU) 2 via the receiving station 4 and the originating station 5. (j in the diagram).

When C-NCU2 detects this polarity reversal,
A terminal selection code for selecting a terminal number of a meter sensor, etc. connected to the terminal network control unit (TNR-NCU) 6 is sent to the terminal network control unit (TNR-NCU) 6 (k in the figure).

In this state, the C-NCU 2 and the terminal network control unit (TNR-NCU) 6 enter a complete data communication mode, and data is sent and received between the CPU 1 and the meter sensor, etc. 7 (l in the figure). In this case, if a call is made (off-hook) during data communication, the special trunk (NRT) detects this and sends a visit tone to the center.

When data communication is finished, C-NCU2
Based on the instruction in step 1, the transmission of the no-ringing trunk control signal (NRTS) is stopped, and after the line polarity is restored to normal, the DC loop is opened (from m to o in the figure).

In this way, first, the NRTS is stopped, the special trunk (NRT) 5 is restored, the terminal-side subscriber telephone line 17 is disconnected, and the polarity of the line to be restored is detected, and then the DC loop is opened. It is possible to prevent the telephone from ringing due to noise caused by relays, etc. flowing to the terminal side.

In addition, when the C-NCU 2 continuously connects with another terminal network control unit (TNR-NCU) 6 of the same terminating station switching equipment, the C-NCU 2 stops sending out the no-ringing trunk control signal (NRTS), After the line polarity is restored to a normal state, the no-ringing trunk control signal (NRTS) is sent out again, and the second dial signal is sent out in the same manner.

Next, from CPU1 to the terminal network control device (TNR-
When the isolation test for NCU) 6 is instructed, the isolation test instruction code is sent together with the terminal selection code at k in FIG. Perform a return test at the exit of the connection terminal, and if the result is good, press the space code for a certain period of time or more to C-NCU2.
Please send it back to . If the result is good, it will definitely become a mark code after the predetermined time period or more. In other words, if the result is good, a space code for a predetermined period of time is returned. That is, in this case, the space code is transmitted as upstream data in the data communication mode l in FIG.

In this case, the meter may remain connected to the TNR-NCU 6, and the meter will not be activated unnecessarily.

The C-NCU 2 determines the pass/fail of the test and notifies the CPU 1 of the result.

FIG. 3 shows an example of a circuit of a center network control unit (C-NCU) 2 according to an embodiment of the present invention, which is means for realizing the functions described in FIGS. 1 and 2. 21 is a loop closure and polarity reversal detection circuit, 2
2 is a dial signal sending circuit that sends out the first and second dial signals, 23 is a no-ringing trunk control signal (NRTS) sending circuit, 24 is a modulation circuit for data modulation, and 25 is a 400Hz reception circuit for detecting dial tone or visit tone. 26 is a second dial request signal (SDR) receiving circuit, 27 is a demodulation circuit for data demodulation, 28 is a 2-wire to 4-wire conversion hybrid circuit that combines transmission and reception, 29 is a control circuit, and 30 is an electronic computer ( This is an interface circuit with CPU) 1, etc. Further, a terminal 31 is a telephone line on the center side, and a terminal 32 is a connection terminal with a computer.

Furthermore, during the separation test, 33 sends out the separation test instruction code added to the terminal selection code via the modulation circuit 24, and receives the test result response from the TNR-NCU 6 via the demodulation circuit 27, This is a test determination circuit added to determine the pass/fail of the test and notify the CPU 1 of the result.

In order to realize a no-ringing connection in the system of the present invention, a special trunk, that is, a no-ringing trunk (NRT) 5 is provided at the receiving station 4, and
The terminal is equipped with a terminal network control unit (TNR-NCU) 6, and these are connected to the center network control unit (C-NCU).
2 by combining the first dial signal and the second dial signal.

Furthermore, the center network control unit (C-NCU), which is the core of this polling system, has the function of instructing and determining the results of a separation test at the demarcation point between the terminal network control unit (TNR-NCU) and meters, etc. By doing so, a simple remote testing method becomes possible.

As described above, if the center network control unit (C-NCU) according to the present invention is used, the center network control unit can be simply connected to the subscriber telephone line, and there is no need to take geographical conditions into account. , it is possible to realize a data transmission system that allows continuous calling with call priority and that allows no-ringing connections using the existing switching network. Particularly, in the present invention, a circuit for sending out a no-ringing trunk control signal is provided, and the timing for starting sending out the no-ringing trunk control signal is made to be the same as the timing for starting sending out the first dial signal indicating the number of the no-ringing trunk.
Then, the no-ringing trunk determines that the call based on the first dial signal is normal only when it receives the no-ringing trunk control signal, and sends out a second dial request signal. For this reason, the no-ringing trunk is
It responds only to calls from authorized center network control equipment, and does not respond to simple mistaken calls. As described above, the present invention has the advantage that a no-ringing operation can be performed without malfunction.

Furthermore, by using the same procedure, it is possible to construct a unified system that can perform isolation tests on a huge number of network control devices for terminals scattered over a wide area, without having to visit the terminals directly. In particular, according to the present invention, even if the terminal network control device is malfunctioning and is fixed in space mode, this malfunction can be detected. This is because when the terminal network control device is normal,
This is because, as a result of the test, not only a series of space codes but also a mark is always transmitted after a predetermined period of time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a no-ringing system using a general subscriber telephone line according to the present invention, and FIG.
1 is a diagram showing an operation sequence of the system of FIG. 1, and FIG. 3 is a block diagram showing a circuit of a center network control device according to an embodiment of the present invention. 1... Computer (CPU), 2... Center network control unit (C-NCU), 3... Originating station, 4... Terminating station, 5... No-ringing trunk (NRT),
6...Terminal network control unit (TNR-NCU), 7...
... Information source, 8 ... Subscriber telephone, 21 ... Loop closure and polarity reversal detection circuit, 22 ... First and second
dial signal sending circuit for sending out a dial signal, 23... no-ringing trunk control signal sending circuit, 24... modulation circuit for data modulation, 25...
…400 for dial tone and visit tone detection
Hz receiving circuit, 26... Second dial request signal receiving circuit, 27... Demodulation circuit for data demodulation, 28...
2-wire-4-wire conversion hybrid circuit, 29...control circuit, 30...interface circuit, 33...test determination circuit.

Claims (1)

[Claims] 1 A center network control device that is installed at the entrance of the center-side network of a data transmission system connected to a general subscriber telephone line and operates by being connected to a data processing device such as a computer, which a loop closing circuit for closing a loop between the center network control device and the originating station to which the center network control device is connected in response to an instruction from the originating station; a dial tone and visit tone detection circuit for detecting; a first dial signal sending circuit that receives a number of a no-ringing trunk attached to a destination exchange from the data processing device and sends it as a first dial signal to the originating station; , a second dial request signal receiving circuit that receives a second dial request signal from the no-ringing trunk, and a second dial that sends the subscriber number received from the data processing device to the no-ringing trunk as a second dial signal. It has a signal sending circuit, a polarity reversal detection circuit for detecting polarity reversal from the no-ringing trunk, and a data modulation/demodulation circuit for performing data communication with a terminal network control device connected to the receiving station. , in the center network control device that performs network control and data communication when a general subscriber telephone line is used as a no-ringing system, a no-ringing trunk control signal to the no-ringing trunk is transmitted from the first dial signal sending circuit to the first No-ringing, in which transmission of the no-ringing trunk control signal is started when the dialing signal is transmitted, and transmission of the no-ringing trunk control signal is stopped when the second dialing request signal receiving circuit receives the second dialing request signal from the no-ringing trunk. further comprising a trunk control signal sending circuit, configured to send the second dial request signal to the no-ringing trunk only when receiving the no-ringing trunk control signal after it has been paged by the first dialing signal. Further, when the data processing device instructs the terminal network control device to perform an isolation test, the terminal network control device simultaneously sends a test instruction code to the terminal network control device. It also has a test determination circuit that determines whether the test is good or not based on whether or not a space code is detected for a predetermined period of time from the device, and notifies the data processing device of the result, and also has a separation test function. A center network control device comprising: