KR100544598B1 - Remote meter reading device using dual tone multi-frequency code - Google Patents

Abstract

Disclosed is a remote metering device using a dual tone multi-frequency code that uses a telephone line of a customer but can only remotely read power using a telephone line using only DTMF (dual tone multi-frequency) signals.

The remote meter reading device using the dual tone multi-frequency code according to the present invention is a D-T decoder to output the decoded D-FM code by inputting and decoding a D-T signal based on the dual tone multi-frequency code, a plurality of D-FM A mapping table for storing the code and the control command corresponding to the DMP code. If a ring signal is received from the telephone line, the caller identifier is extracted to check whether the identifier is a predetermined identifier, and if the extracted identifier is a predetermined predetermined identifier, Outputs a control signal for starting F decoding, outputs a control signal for initiating a voice telephone call if not a predetermined identifier, and executes a control command corresponding to the DFM code output from the DFM decoder with reference to the mapping table. Extracting and processing the extracted control commands to output the result data And a control unit, and a DMP encoder for outputting the DFM signal to the meter reading system by encoding the result data.

 DTMF, remote meter reading

Description

Remote meter reading device using dual tone multi-frequency code

1 is a block diagram showing the structure of a remote meter reading apparatus according to a preferred embodiment of the present invention;

2 is a flowchart illustrating an example of a control flow performed by the controller of FIG. 1;

3 is a view for explaining an example of the operation of the remote meter reading apparatus using a dual-tone multi-frequency code according to the present invention.

The present invention relates to a remote meter reading, and more particularly to a remote meter reading device using a dual-tone multi-frequency code that can be remotely read at low power using a DTMF signal using a telephone line of the consumer.

To read water, city gas and electricity usage, meter readers visit customers directly. However, the conventional meter reading method in which the meter reader visits the customer directly increases the labor cost of the meter, and in the end, the burden on the consumer increases, and when a meter for meter reading is installed in the customer, no one is in the customer when the meter visits. There is a problem that there are many cases of visiting again.

In order to solve this problem, a remote meter reading service system has been developed. The remote meter reading service system allows the meter readers to read the meter data from a remote location without visiting the customer. Information can be collected by telephone line, power line, or radio frequency, and can be linked to computer programs to identify bills and demand patterns. Conventional remote metering devices use telephone lines but use a modem to meter. However, similar to those used for facsimile, a high speed digital signal processing device having a wide processing frequency band is used for a remote meter reading device using a conventional modem. In general, such a digital signal processing device is provided with a separate power source that consumes considerable power. Should be. Therefore, the conventional remote meter reading device using a telephone line has a problem that the installation and maintenance is not easy because a separate power source is required.

On the other hand, the mechanical pulse method was used in the past for dialing a landline telephone, but the pulse tone method is used now. Currently used pulse tone method, Multi Frequency Code is one of four frequencies of low frequency group (697, 770, 852, 941 Hz) and high frequency group (1209, 1336, 1477, 1633 Hz) simultaneously. Two digits constitute one digit, which is also referred to as a dual tone multi-frequency code (hereinafter referred to as DTMF). The DTMF signal is about 10 times faster than dial pulses and has a low rate of error in dialing. In addition, the occupancy time of the signaling device is short, there are many kinds of digit information, and it is available for various special services.

The DTMF signal is selected and used one by one from two mutually exclusive frequency groups consisting of four frequencies in the voice band. Among the major specifications of the DTMF signal, the digit speed is 11 digits / sec, the digit pause time is at least 40 Hz, and the digit duration. Has a minimum of 40Hz, frequency error of ± 1.8%, and frequency distortion of less than 20%. The use of the DTMF signal in the exchange is mainly a function of receiving the DTMF signal, which is necessary to detect the numeric information of the subscriber by receiving the DTMF signal generated from the pushbutton subscriber. In addition, in order to test the reception function of the DTMF signal, a function of transmitting a DTMF signal having the same specifications as the DTMF signal generated from a telephone is required. However, these DTMF signals are standardized to be used for dialing, and a separate modem is actually used to support data communication.

The technical problem to be achieved by the present invention is to provide a remote metering device using a dual tone multi-frequency code, which is good in maintenance by being driven only by its own power supplied from a telephone line because power consumption is low by not using a separate modem.

In the remote meter reading device using a dual-tone multi-frequency code according to the present invention for achieving the above technical problem, in the remote meter reading device of the customer connected to the meter reading system of a remote place through a telephone line,

A demultiplexer decoder for outputting a decoded demultiplexer code by inputting and decoding a demultiplexer signal based on a dual tone multi-frequency code;

A mapping table for storing a plurality of DMP codes and control commands corresponding to the DMP codes;

When a ring signal is received from the telephone line, the caller identifier is extracted to check whether the identifier is a predetermined identifier. If the extracted identifier is a predetermined identifier, a control signal for starting DMP decoding is output. A control unit for outputting a control signal to start the data, extracting a control command corresponding to the DMP code output from the DMP decoder with reference to the mapping table, and outputting the result data by processing the extracted control command; And

And a DFM encoder for outputting the DFM signal to the meter reading system by encoding the result data.

Further, it is preferable that the control command is at least an instruction indicating an integrated value request and the result data is integrated value data.

The controller may output a data identifier indicating that the result data is to be transmitted together with the result data, and the DMP encoder may detmp the result data together with the data identifier.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the structure of a remote meter reading apparatus according to a preferred embodiment of the present invention. 2 is a flowchart illustrating an example of a control flow performed by the controller of FIG. 1. Referring to Figure 1, the remote meter reading device according to a preferred embodiment of the present invention is connected to the DTM FM decoder 102, the customer's remote meter reading device connected to a remote meter reading system connected to a public switched telephone network through a telephone line A table 104, a control unit 106, and a DMP encoder 108.

First, when calling from the meter reading system of the waterworks office (step S202), the control unit 106 receives a ring signal from the telephone line, extracts a caller ID, and the extracted identifier indicates a waterworks office. If the extracted identifier is a predetermined predetermined identifier, the remote meter reading apparatus according to the present invention receives a call from the remote meter reading system (step S206). It is possible to detect that the incoming call is received by the on-hook sound. Next, the meter reading system of the remote waterworks office outputs a DMP encoded signal requesting the integrated value, for example, "A" (step S208), and the control unit 106 of the remote meter reading apparatus according to the present invention. Outputs a control signal for starting DMP decoding (step S210).

Next, the DMP decoder 102 inputs a DMT signal based on a dual tone multi-frequency code and outputs a decoded DMP code by performing DTP decoding (step S212). The mapping table 104 stores a plurality of DMP codes and control commands corresponding to the DMP codes. That is, the DTMF code and the corresponding control command are mapped to the mapping table 104. For example, a control instruction called "integrated value request" is mapped to DTMF code "A".

Now, the controller 106 extracts a control command corresponding to the DMP code output from the DMP decoder 102 by referring to the mapping table 104 and processes the extracted control command to obtain the result data. Output (step S214). That is, when the DTMF code "A" is received, the integrated value is read and used as the result data. Now, the DMP encoder 108 performs DMP encoding of the result data, that is, the integrated value data (step S216) and outputs the encoded DFM signal to the meter reading system (step S218).

On the other hand, it is checked whether the extracted identifier is a predetermined identifier indicating a water establishment (step S204), and if the extracted identifier is not a predetermined identifier, a control signal is output to start a voice telephone call (step S220). )

The amplifier 110, the data access array 112, and the telephone line I / F (interface) unit 114 shown in FIG. 1 are in charge of amplification and interface processing for a public switched telephone network (PSTN) interface. 120 detects the metering pulse, LCD 122 displays the user interface and metering results, keypad 124 is responsible for input for the user interface, detailed within the scope of not disturbing the core of the present invention. Omit the description.

A caller identifier extracting unit 130 for extracting a caller ID, a phone line monitoring unit 132 for monitoring a telephone line, a ring detection unit 134 for detecting a ring signal, an off hook control unit 136, And the power distribution circuit unit 138 may be included in the control unit 106 may be implemented, but is shown as separated from the control unit 106 for convenience of description. The power distribution circuit unit 138 is a circuit for distributing power through a limited telephone line.

On the other hand, the mapping table which specifies the correspondence relationship between the DTMF code and the control command or the result data is provided not only in the customer's meter reading device but also in the remote meter reading system. Therefore, the remote meter reading system receiving the DMP signal demultiplexes the received DTMF signal to obtain a DMP code. Here, the DMP code is integrated value data, for example. However, the control command based on the DFM signal transmitted from the remote meter reading system to the reader's reading device may be a serial number request of the customer reading device, and the result data becomes the serial number data of the customer reading device. The remote meter reading system includes a mapping table. The mapping table stores a plurality of DFM codes, control commands corresponding to the DFM codes, and / or data identifiers to be described below.

In the above embodiment, when the integrated value data is requested from a remote meter reading system, the receiver's metering device transmits the meter data, which is the result data, without a data identifier, as an example. However, the receiver reads the data for more accurate processing. More preferably, a data identifier for identifying the type of data is attached and transmitted.

That is, in another embodiment, the controller may output a data identifier indicating that the result data is to be transmitted together with the result data, and the DMP encoder may detmp the result data together with the data identifier. Do. For example, the DMP code "A" is mapped to a control command requesting the integrated value, and the reading device of the receiver reads the integrated value and indicates that the integrated value data is a DMT code "B" and the predetermined result data. DTI-F encodes the integrated value data "042941" of the digit and transmits the DTI-F signal to a remote meter reading system. That is, the control unit may output a data identifier indicating that the result data is transmitted together with the result data, and the DMP encoder may perform DTF encoding of the result data together with the data identifier. In addition, the control command may be the next reading time, error information, software change information.

In the above embodiment, the call for the meter reading in the remote meter reading system has been described as an example, but it is also possible to determine to call the meter reading system from the receiver's meter. In this case, it is the core of the present invention to encode and transmit the signal that transmits the integrated value after the call based on the DTF. In this case, when the incoming call is received from a remote meter reading system, the incoming value is read from the DFM encoder. Start TMP encoding. The encoded DMP signal is decoded in a remote meter reading system to obtain an integrated value.

3 is a view for explaining an example of the operation of the remote meter reading apparatus using a dual-tone multi-frequency code according to the present invention. Referring to FIG. 3, when the remote meter reading system 30 requests the integrated value using the DFM signal, the customer meter reading device 32 provides the integrated value data using the DFM signal. Here, it should be noted that both the request for the integrated value and providing the integrated value data use a DFM signal.

The remote meter reading device using the dual tone multi-frequency code does not include a separate modem. The communication procedure described above functions similarly to a modem, but in practice, DTF-based signals have a lower power consumption than the frequency band of the signal used for data communication by the modem, and thus require low power and power supplied from a telephone line. Is enough. In other words, the remote meter reading device using the dual tone multi-frequency code as described above does not use a separate modem, so the power consumption is low, and only the own power supplied from the telephone line is used to maintain and maintain the device as compared to a remote meter reading device using a conventional phone line. There is an advantage that it is good.

As described above, the remote meter reading device using the dual tone multi-frequency code according to the present invention is driven by only its own power supplied from a telephone line because power consumption is low by not using a separate modem, compared to a remote meter reading device using a conventional telephone line. The advantage is good maintenance.

Claims (3)

A customer remote meter reading device connected to a meter reading system at a remote location via a telephone line, A demultiplexer decoder for outputting a decoded demultiplexer code by inputting and decoding a demultiplexer signal based on a dual tone multi-frequency code; A mapping table for storing a plurality of DMP codes and control commands corresponding to the DMP codes; When a ring signal is received from the telephone line, the caller identifier is extracted to check whether the identifier is a predetermined identifier. If the extracted identifier is a predetermined identifier, a control signal for starting DMP decoding is output. And outputs a control signal to the DMP code by referring to the mapping table in which a plurality of DMP codes and control commands corresponding to the DMP codes are stored. A controller for extracting a control command to be output and processing the extracted control command to output result data; And And a DFM encoder for outputting the DFM signal to the meter reading system by encoding the result data. And the control command is at least a command indicating an integrated value request and the result data includes integrated value data. delete The method of claim 1, The control unit outputs a data identifier indicating that the result data is transmitted together with the result data, and the DMP encoder encodes the result data with the data identifier by using the dual tone multi-frequency. Remote meter reading device using code.

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