JPH05137176A - Method and device for collecting information - Google Patents

Abstract

PURPOSE:To easily extend a system to which an information collecting device is applied by reducing the cost related to change and adjustment of the device accompanied with the increase of the number of slave stations. CONSTITUTION:The question signal subjected to spectrum spread by PN series Sa1, Sa2... whose mutual correlations values are small correspondingly to plural slave stations Ca1, Ca2... is sent from a master station Pa. The response signal based on prescribed information subjected to spectrum spread by PN series Sb1, Sb2... whose mutual correlation values are small correspondingly to respective slave stations is sent from a required slave station, and information based on the response signal is gathered by the master station Pa. Thus, information from slave stations is quickly gathered, and channels are effectively used to easily increase the number of slave stations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows an inquiry signal to be transmitted from a master station to slave stations provided at a plurality of remote locations, and a response signal based on predetermined information can be transmitted from a required slave station. The present invention relates to a method and apparatus for a master station to collect the information based on a response signal.

[0002]

2. Description of the Related Art Conventionally, a facility for supplying electric power to a remote place uses a breaker to prevent damage to the power supply source or damage to the power line due to overcurrent when the power line causes a failure such as a short circuit. It is common to disconnect the connection between the power supply source and the power line, but at the same time, locate the accident section as quickly as possible, change the power transmission route so as to avoid that location, and re-power the healthy section. In many cases, a power distribution state monitoring system is provided for the purpose of minimizing the power failure time.

FIG. 4 is a block diagram showing an example of a conventional power distribution state monitoring system. This is a system in which a master station P is added to a power supply source 1 and measurement points a, a, at various points along the power line 2 are provided. A plurality of slave stations C1 to Cn are respectively arranged in ... And these slave stations and the master station P are connected by a communication line 3. The master station P includes a transmitter 4 and a receiver 5, and each slave station has a receiver 6 and a transmitter 7 corresponding thereto.
Have and. In this system, when the power line 2 is short-circuited and the breaker B operates, the transmitter 4 of the master station P, which has detected that fact, sequentially sends out an inquiry signal assigned to each of the slave stations via the communication line 3, and each slave Gather information based on station sensors 8. As a result, the accident section is detected and power is re-supplied to a healthy section excluding the section. Such an information collecting method is generally called polling.

However, in such a polling-type information collecting system, the master station transmits the interrogation signal to each slave station until it detects a response signal to the interrogation signal, and then interrogates other slave stations. As the number of slave stations increases, it takes a long time to detect an accident section, which is an obstacle to shortening the power failure time in a sound section.

In order to solve such a problem, there has been conventionally proposed a method for simultaneously accessing a plurality of slave stations by a frequency multiplexing system as shown in FIG. That is, in the system shown in this figure, when the power supply source goes into a power failure state as described above, the transmitter 9 of the master station Px detects that fact, and the interrogation signal generated from the signal generator 10 is transmitted to the modulators 11, 11, …
To enter. In the modulator, a generator H that generates carriers f1 to fn having different frequencies assigned to each slave station is provided.
1 to Hn, each of which is modulated by the interrogation signal and then sent to the communication line 3. On the other hand, each of the slave stations Cx1 to Cxn includes a filter 13 that passes only the carrier signal assigned to the receiving unit 12, demodulates the interrogation signal from the master station by a demodulator (not shown), and identifies the discriminator 14 When it is detected that the question signal is addressed to your station,
The transmitter 15 is activated to generate a response signal. The transmitter 1
Reference numeral 5 determines whether or not the electrical characteristics of the measurement point are normal based on the output of a predetermined sensor arranged at various points along the power line by the signal generator 16 and generates a response signal based on the determination result. .. Further, it is provided with a generator 17 and a modulator 18 for generating any one of carrier waves fa1 to fan having a frequency separately determined for each slave station, and modulates the allocated carrier wave with the response signal to make a communication line. Send to 3. The response signals thus returned are filters B1 to Bn for extracting the respective carrier waves fa1 to fan of the receiver 19 of the master station Px, and a demodulator M1 provided for each of them.
To Mn and then input to the determiner 20 to collect the determination result information of all the measurement points of the power line. Therefore, according to this system, the master station can receive the response signal from each slave station at the same time and can collect necessary data in a short time, so that the power failure time for a healthy section can be shortened.

However, even if such a system is adopted, the following problems occur. That is, in order to make effective use of the communication line extending along the power line, when the communication means other than the power distribution monitoring system described above, for example, is also assigned for transmission of a power line insulation monitoring signal or carrier telephone signal. Considering that, it is necessary to prepare an empty channel in advance, assuming that the number of slave stations will increase with the expansion of the power distribution range of the power supply facility, which is disadvantageous for effective use of the channel. Not only that, when the total number of channels is insufficient, it is necessary to reallocate channels to the existing communication equipment from the beginning, which causes a problem that the cost for changing and adjusting the equipment increases. It was In addition, such a problem is not limited to the power distribution monitoring system as described above, and the master station sends an inquiry signal to a plurality of slave stations, and each slave station returns a response signal based on predetermined information. This has been a widespread problem even in the system where the master station collects such information.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional information collecting apparatus as described above, and can collect information from a plurality of slave stations quickly and at the same time make effective use of channels. Moreover, it is an object of the present invention to provide an information collecting method and device in which the number of child stations is extremely simple.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, an information collecting method and device of the present invention are configured as follows. That is, as the interrogation signal for each of the plurality of slave stations, the interpolated interrogation signal of the PN sequence having a small cross-correlation value is used. Or a predetermined narrow band signal is used as an interrogation signal for each of a plurality of slave stations. For the return of the response signal from each child station to the parent station, a PN sequence having a small cross-correlation is assigned to each child station, and thereby a spread spectrum response signal is simultaneously generated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a configuration diagram showing an embodiment in which the information collecting apparatus according to the present invention is applied to a power distribution state monitoring system. In the figure, reference numeral 21 is an information collecting device, and a master station Pa attached to the power supply source 1 and slave stations Ca1 to Can arranged mainly at each section switch installation location of the power line are connected by a communication line 3 to each other. Further, the power distribution state monitoring system is configured by connecting the input terminals of the respective slave stations to any of measurement points a, a, ... Among them, the master station Pa has a transmitter 22 and a receiver 23, and the transmitter 22 has one signal generator 24 for generating an inquiry signal and a PN assigned to each slave station and having a small correlation with each other. Series Sa1 to San
And PN sequence generators Ga1 to Gan that generate the respective signals and modulators Ma1 to Man that spread the spectrum with the PN sequences Sa1 to San assigned to the respective slave stations as the output of the signal generator 24 as a modulation signal. .. In addition, the receivers 23 are connected to each other and the PN sequence Sa
PN sequence Sb1 with small cross-correlation with each of 1 to San
To Sbn, and generate any of these
Sequence generators Gb1 to Gbn and n demodulators Da1 to Dan that despread with the PN sequences Sb1 to Sbn of each slave station to demodulate the spread signal transmitted from the slave station.
And a determiner 25 for locating the faulty section of the power line based on the demodulated signal.

On the other hand, each of the slave stations Ca1 to Can is provided with a receiving section 26 and a transmitting section 27, and the receiving section 26 has a demodulator 2
8 is connected to the communication line 3 and the output terminal of a PN sequence generator 29 for generating any of the PN sequences Sa1 to San assigned to the local station is connected to the demodulator 2
8 and the output end of the demodulator 28 is connected to the input end of the transmitter 27 via the discriminator 30. In addition, the transmitter 27 of each slave station connects the output end of the sensor 8 and one input end of the modulator 32 to the input end and the output end of the signal generator 31 which respectively generate a predetermined response signal. , The PN sequences Sb1 to Sb assigned to the own station
The output terminal of the PN sequence generator 33 for generating any of n is connected to the other input terminal of the modulator 32, and the output terminal of the modulator 32 is connected to the communication line 3.

The information collecting device 21 configured as described above operates as follows. That is, in this device, when an excessive current flows due to, for example, a short-circuit of the power line 2 and the transmission unit 22 of the master station Pa detects a status signal indicating that the breaker B has operated, the transmission unit 22 outputs the signal from the signal generator 24. A common interrogation signal is generated for each of the stations Ca1 to Can, and
Modulators Ma1 to Man spread the spectrum of the interrogation signal with each of the PN sequences Sa1 to San and send out the multiplexed signal to the communication line 3. On the other hand, the reception unit 26 of each slave station demodulates the interrogation signal by correlating the multiplexed signal transmitted from the master station Pa by the demodulator 28 with the PN sequence assigned to the local station, and at the same time, the discriminator When 30 is used to detect the interrogation signal, the transmitter 27 is operated. The transmission unit 27 inputs a measurement signal based on the measurement value of the current and voltage at the measurement point a connected to the own station via the sensor 8 using the signal generator 31, and outputs the measurement signal of the measurement point a from the signal. It is determined whether or not the electrical characteristics are normal, and a response signal is generated only when an abnormality is found in the determination result, and the response signal is assigned via the modulator 32 to the PN sequence Sb1 assigned to the own station. A signal whose spectrum has been spread by any one of Sbn to Sbn is transmitted to the communication line 3.

The response signal thus returned is received by the demodulators Da1 to Dan of the receiving unit 23 of the master station Pa, and the response signals of the respective slave stations are obtained by correlating with the PN sequences Sb1 to Sbn. Of the measurement points a, a, ... Of the power line 2 based on these response signals by using the determination device 25, and the determination result information for the required electrical characteristics of the measurement points a, a ,. Find out if the location is short-circuited. Next, a control signal for changing the power transmission path so as to avoid the short-circuited portion that is located is transmitted to each transmission path switching device via a power transmission path control means (not shown). After that, the breaker B is used to connect the power supply source 1 and the power line 2 to each other to enable the normal power distribution state to be restored.

Therefore, according to the information collecting device 21,
The parent station Pa sends a spread spectrum multiplex signal of a common inquiry signal to each child station, and all the child stations that have detected an abnormality send back a response signal that is spread spectrum with a PN sequence having a small mutual correlation. Therefore, compared to the conventional power distribution monitoring system shown in FIG. 5, it is possible to collect the required judgment result information at the slave station in a short time, so that the power supply source is in a power failure state. It is possible to shorten the time required to return from the normal power distribution state. In addition, according to this device, there are generally only a few faulty points on the power line, and the number of spread spectrum signal transmissions of each slave station does not overlap each other. The increase in the noise level of the line can be reduced. Further, when the number of slave stations is increased in accordance with the expansion of the power supply range of the power supply equipment, the information collecting device 21 having this configuration creates a PN sequence having a small cross-correlation with each of the PN sequences Sa1 to San and Sb1 to Sbn described above. It suffices to add a transmission / reception block as a spread signal to the master station, and it is easy to add slave stations. Furthermore, since the information collecting device 21 adopts the spread spectrum method, it is possible to use the signal transmission line between the master station and each slave station for other signal transmission. That is, if a narrow band signal is used for other signal transmission, interference with a spread spectrum signal is small, and even with the same spread spectrum system, there is no problem if PN sequences having a small correlation are used.

In the above embodiment, the transmitter 2 of the master station Pa is used.
The reference numeral 2 assigns an interrogation signal common to each slave station to each slave station and demodulates the multiplexed signal by spectrum spreading with each of the PN sequences Sa1 to San, but the present invention is not limited to this. Various modifications are possible as shown below. FIG. 2 is a block diagram showing another embodiment of the present invention. The difference of this example from the system of FIG. 1 is that the PN sequence of the inquiry signal transmitted from the master station to the slave station is one and all That is, the same signal was sent to the slave station. That is, the transmission unit 34 of the master station Pb connects the output end of the signal generator 24 that generates the interrogation signal common to each slave station to one input end of the modulator Mc, and the PN sequences Sb1 to Sbn are The output end of the PN sequence generator Gc for generating the PN sequence Sc having a small cross-correlation is connected to the other input end of the modulator Mc, and the output end of the modulator Mc is connected to the communication line 3. On the other hand, the reception unit 35 of each of the slave stations Cb1 to Cbn has the P
It goes without saying that a PN sequence generator 36 for generating the N sequence Sc is provided.

The operation of this information collecting apparatus is the same as that shown in FIG. 1 except that the inquiry signals transmitted from the master station to the slave stations are all the same. Since the labor for changing the information collecting device is less than that of the above-described embodiment, there is an advantage that the cost for changing and adjusting the device due to the increase of the slave stations can be reduced as compared with the embodiment of FIG.

The present invention also provides the above-mentioned information collecting device as shown in FIG.
It may be modified as shown in FIG. FIG. 3 is a block diagram showing still another embodiment of the present invention. In this embodiment, the interrogation signal transmitted from the master station to the slave station is a spread spectrum signal instead of a narrow band signal such as a tone signal. Is different from FIGS. That is, the transmitter 37 of the master station Pc connects the output end of the signal generator 38 that generates a signal having a narrow signal band, for example, a tone signal, to the communication line 3. On the other hand, the slave stations Cc1 to Cc
Each receiving unit 39 connects the output end of the filter 40 whose pass band is the signal band of the tone signal to the input end of the transmitting unit 27 via the discriminator 30, and connects the input end of the filter 40 to the communication line. Connect to 3.

This information collecting device operates as follows when applied to a power distribution monitoring system. That is, when the breaker operates as described above and the transmission unit 37 of the master station Pc detects the status signal, the transmission unit 37 sends a tone signal from the signal generator 38 to the communication line 3. On the other hand, the reception unit 39 of each slave station extracts the tone signal transmitted from the master station Pc via the filter 40, and when the discriminator 30 detects the tone signal, activates the transmission unit 27. After that, based on the information collected by the master station, it is possible to control the power supply to the healthy section again.
And the same as the example of 2.

According to the system shown in this example, since it is not necessary to provide each slave station with means for demodulating a complex and expensive spread spectrum signal, it is economical when a large number of slave stations are provided. There is such a big merit. That is, since the information collecting device uses a tone signal with a narrow signal band for the inquiry signal output from the master station to the slave station, and uses a spread spectrum signal for the signal transmitted from each slave station to the master station,
The amount of interference between the transmission signal of the master station and the transmission signal of the slave station can be made smaller than that in the above-mentioned embodiment, and even if the signal transmissions of both stations overlap, each station transmits the signal transmitted by its own transmitter. It is possible to improve the deterioration of the receiving sensitivity of the receiving unit caused by the fact that the signal goes around to the receiving unit of the own station.

Further, in the above-mentioned embodiment, each slave station generates the response signal only when the judgment result for the measurement signal from the sensor is abnormal, but the present invention is not limited to this, and the inquiry signal or the tone. It will be apparent that the function of the slave station may be simplified by generating a response signal based on the determination result when a signal is detected.

Although the present invention is applied to the power distribution monitoring system in the above-described embodiments, the present invention is not limited to this, and the master station sends out an inquiry signal to a plurality of slave stations via a communication line, and the required signal is transmitted. It may be applied to a system in which a response signal based on predetermined information is sent back from a slave station through a communication line to collect the information, and as described above, a signal is transmitted between the master station and a small station. It is obvious that the communication medium to be transmitted is not limited to a wire such as a power line and an optical fiber, and may be wireless.

[0021]

Since the present invention is constructed and functions as described above, the cost for changing and adjusting the information collecting device due to an increase in the number of slave stations is reduced. It is effective in facilitating the expansion of the system to which is applied.

[0022]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a modified embodiment of the present invention.

FIG. 3 is a configuration diagram showing a modified embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional power distribution monitoring system.

FIG. 5 is a configuration diagram showing another conventional power monitoring system.

[Explanation of symbols]

Pa parent station Ca1 to Can slave station 3 communication line 21 information collecting device 22 and 27 transmitter 23 and 26 receiver 24 signal generator 25 determiner 28 and Da1 to Dan demodulator 29, 33, Ga1 to Gang and Gb1 to Gbn
PN sequence generator 30 discriminator 31 signal generator 32 and Ma1 to Man modulator

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location H04Q 9/00 321 E 7170-5K (72) Inventor Atsushi Yokoi Atani 2-chome, Samukawa-cho, Takaza-gun, Kanagawa Prefecture No. 1 to 1 within Toyo Communication Equipment Co., Ltd.

Claims (5)

[Claims] 1. A query signal, which is spread spectrum with a PN sequence having a small cross-correlation value for each of a plurality of slave stations, is transmitted from a master station, and spread spectrum is spread by a PN sequence having a small cross-correlation for each slave station. An information collecting method, characterized in that a response signal based on the predetermined information is transmitted from a required slave station, and the master station collects the information based on the response signal. 2. Predetermined information obtained by transmitting an inquiry signal, which is spread spectrum with one PN sequence to each of a plurality of slave stations, from a master station, and spread spectrum with a PN sequence having a small cross-correlation value for each slave station. A method for collecting information, characterized in that a response signal based on the response signal is transmitted from a required slave station, and the master station collects the information based on the response signal. 3. A response signal based on predetermined information obtained by transmitting a predetermined narrow band signal to each of a plurality of slave stations from the master station and performing spectrum spread on a PN sequence having a small cross-correlation value for each slave station. Is transmitted from a required slave station, and the master station collects the information based on the response signal. 4. An inquiry signal is sent from a master station to a plurality of slave stations, and a response signal based on predetermined information is sent from a required slave station, and the master station collects the information based on the response signals. In the information collecting apparatus, the master station has means for spectrum spreading the interrogation signal with each PN sequence having a small cross-correlation value determined corresponding to each slave station. 5. An inquiry signal is transmitted from a master station to a plurality of slave stations, and a response signal based on predetermined information is transmitted from a required slave station, and the master station collects the information based on the response signals. The information collecting device is characterized in that each slave station comprises means for spectrum spreading a response signal based on predetermined information by a PN sequence previously assigned to each slave station and having a small mutual correlation value. ..