JPH0545453A - Data collecting apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an excellent data collection device capable of determining whether or not a data transmission device is located within a certain distance and limiting a communication area with the data transmission device to a certain range. The purpose is to do. A data acquisition system for transmitting a quasi-microwave carrier signal and receiving a modulated wave in which the carrier signal retransmitted from at least one data transmitting device that has received the quasi-microwave signal is modulated by identification information in the data transmitting device. A device for demodulating the modulated wave to obtain the identification information, a distance discriminating circuit for discriminating whether or not a separation distance of the data transmitting device is within a certain distance, and the distance discriminating circuit. And a signal control circuit which sends out the identification information when it is determined that the separation distance is within the predetermined distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data collecting device used for identifying numbers of all moving bodies such as trains and automobiles.

[0002]

2. Description of the Related Art Conventionally, a data collecting apparatus of this type includes a circuit for detecting and receiving quasi-microwave and re-radiating a modulated wave obtained by modulating a radio wave in accordance with ID information which is identification information contained in a mobile body. It is used in combination with a data transmission device, and is provided with a quasi-microwave band oscillation circuit and a power amplification circuit. Furthermore, when the ID information is read out by receiving and demodulating the modulated wave, the ID information is sent to an external device. Is configured to communicate.

[0003]

However, in the above-mentioned conventional data collection device, when the re-radiated wave from the data transmission device is received, the separation distance to the data transmission device cannot be determined, so that the communication area is effective. There is a problem that the reception range cannot be limited to a certain range, and uncertain ID information received from a data transmission device existing outside the range cannot be rejected.

The present invention is intended to solve such a conventional problem, and determines whether or not the data transmission device is located within a certain distance, and makes the communication area with the data transmission device constant. It is an object of the present invention to provide an excellent data collection device that can be limited in range.

[0005]

In order to achieve the above-mentioned object, the present invention comprises a circuit for demodulating and reading ID information when a re-radiated wave from a data transmission device is received. Only when it is determined that the position of the data transmission device at the time of reading exists within a certain distance, the demodulated ID information is transmitted to the external device.

[0006]

Therefore, according to the present invention, when the modulated wave from the data transmission device is received, the separation distance to the data transmission device can be determined, so that the communication area is limited to a certain range,
It is possible to prevent the reception ID information from the data transmission device existing outside the range from being transmitted to the external device.

[0007]

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

FIG. 1 shows an embodiment of the present invention. In FIG. 1, 11 is an oscillating circuit that generates a quasi-microwave carrier signal, 12 is a power amplifier circuit that amplifies a carrier signal obtained from the oscillating circuit, 13 is a circulator that switches between transmitting and receiving, 14 is an antenna, and 15 Is a data transmitting device that receives a carrier wave signal radiated from the antenna 14 and modulates the carrier wave signal to re-radiate the modulated wave signal; 16 is a decoding circuit that decodes the modulated wave signal obtained through the antenna 14 and the circulator 13; Is the data transmission device 1
A distance measuring circuit that measures the distance to 5 to generate distance data, 21 is a reference distance setting circuit that sets a reference distance, and 17 is distance data obtained from the distance measuring circuit 18 and is obtained from the reference distance setting circuit 21. A distance discriminating circuit for comparing and discriminating with a reference distance and issuing a discriminating signal, 19 is a signal control circuit for controlling transmission of a reception signal obtained from the decoding circuit 16 according to the discrimination signal from the distance discriminating circuit 17, and 20 is a reception signal. Is a connection terminal for sending out to an external device (not shown).

Next, the operation of the configuration shown in FIG. 1 will be described. The carrier wave signal from the oscillator 11 is the power amplifier circuit 1
2 and the circulator 13 in the transmission mode state, the light is radiated from the antenna 14 and transmitted to the data transmission device 15. In the received data transmission device 15, the carrier wave signal is modulated by the ID information in the data transmission device, and the modulated wave signal is re-radiated toward the antenna 14.
The modulated wave signal received by the antenna 14 is supplied to the decoding circuit 16 via the circulator 13 in the reception mode state, demodulated and supplied to the signal control circuit 19.

On the other hand, the distance data obtained from the distance measuring circuit 18 and the reference distance obtained from the reference distance setting circuit 21 are compared and discriminated. If the distance data is within the reference distance, the signal control circuit 19 is notified. Received signal connection terminal 20
A discrimination signal to be sent to an external device is given. When the distance data exceeds the reference distance, the received signal is not sent to the external device. Since this reference distance is set in the communication area where a reception signal can be obtained from the data transmission device without error, an uncertain reception signal from the data transmission device existing at a distance where an error can occur is not transmitted to an external device. ..

FIG. 2 is a diagram showing an example of actual operation of the data collection device according to the present invention. In this figure, 22 is 1 in FIG.
Reference numerals 1 to 21 denote data collection devices; 23, a mobile body having a data transmission device 24; 25, a mobile body having a data transmission device 26; and 27, a communication lane.

Now, the moving body 23 having the data transmission device 24 is connected to the communication traffic lane 2 in front of the data collection device 22.
When it passes through the range of 7, the data collection device 22 determines that it is within the reference distance, and sends the received ID information of the mobile unit 23 sent from the data sending device 24 to the external device. However, the data transmission device 2 attached to the moving body 25 passing outside the communication traffic lane 27
6 is the ID received from the data transmission device 26 when the data collection device 22 determines that the reference distance is exceeded.
It is possible to prevent information from being sent to an external device.

As described above, according to the above-described embodiment, when the modulated wave from the data transmission device is received, the separation distance between the data collection device and the data transmission device can be discriminated, so that the communication area becomes effective. Since it is possible to limit the communication to a certain range, it is possible to prevent uncertain ID information received from a data transmission device existing outside the range from being transmitted to an external device.

[0014]

As is apparent from the above embodiment, the present invention is provided with a circuit for demodulating and reading ID information when a modulated wave from a data transmission device is received, and at the time of reading the ID information, The data transmission device is provided with a distance discriminating circuit for discriminating whether or not the device exists within a certain distance, and when the result of the discrimination by the distance discriminating circuit determines that the data is within the certain distance, the obtained ID information is transmitted to an external device. When it is determined that the distance exceeds the certain distance, it is desirable to prevent the ID information from being sent to the external device.

This has the advantage that the communication area can be limited to a certain range, and it is possible to prevent uncertain ID information received from a data transmission device existing outside the range from being transmitted to an external device. Have an effect.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an embodiment of a data collection device according to the present invention.

FIG. 2 is a schematic diagram showing an actual operation example of a data collection device according to the present invention.

[Explanation of symbols]

 11 oscillation circuit 12 power amplification circuit 13 circulator 14 antenna 15 data transmission device 16 decoding circuit 17 distance determination circuit 18 distance measurement circuit 19 signal control circuit 20 external device connection terminal 21 reference distance setting circuit 22 data collection device 23, 25 moving body 24 , 26 Data transmission device 27 Communication traffic lane

Claims (1)

[Claims] 1. A quasi-microwave carrier signal is transmitted, and a modulated wave obtained by modulating the carrier signal retransmitted from at least one data transmitting device that has received the carrier signal with identification information in the data transmitting device is received. A data collection device, a decoding circuit that demodulates the modulated wave to obtain the identification information, a distance determination circuit that determines whether or not the separation distance of the data transmission device is within a fixed distance, and this distance determination And a signal control circuit that sends the identification information when the circuit determines that the separation distance is within the predetermined distance.