JP3107994B2 - Telemetry communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telemetry communication apparatus for collecting information on the time of a certain event detected in a remote station distributed in a remote place from a master station.

[0002]

2. Description of the Related Art Conventionally, as this type of telemetry communication device, there is, for example, a communication device having a configuration shown in FIG. In this communication device, a master station 61 and each slave station 62 are connected by an optical fiber line 63, and a branch point or an optical coupler 64 is provided at a branch point. Each of the slave stations 62 is provided with a sensor 65 for detecting occurrence of an event such as a surge current or a seismic wave due to a lightning strike.

In such a configuration, the master station 61 to each slave station 6
2 uses a spread spectrum communication system. In other words, the carrier is first-order modulated by the signal to be transmitted to the slave station 62, and the transmission signal is a narrowband signal 1
It is converted to the next modulated signal. The primary modulation signal is further subjected to secondary modulation by a pseudo noise code (PN code),
The signal band is converted into a spread secondary modulation signal.

[0004] In the slave station 62, the secondary modulation code transmitted from the master station 61 is despread, returned to a narrow band signal, and demodulated. At this time, the phase of the PN code included in the secondary modulation signal received from the master station 61 and the phase of the PN code generated in the slave station are synchronized.

When a signal corresponding to an event at the sensor 65 of the slave station 62 is detected, the detection signal is transmitted to the master station 61. The master station 61 knows the event occurrence time or the detection time based on the detection signal received from the slave station 62.
When a signal is simultaneously detected by the sensor 65 of each slave station 62,
These detection signals are transmitted from the slave stations 62 to the optical fiber line 63, and multiplex communication is performed. Known multiplex communication technologies include frequency division multiplex communication (FDM), time division multiplex communication (TDM), code division multiplex communication (CDM), and wavelength division multiplex communication (WDM).

[0006]

However, in the above-mentioned conventional telemetry communication device, even if a certain event occurs at the same time and a signal is detected at each sensor 65 of each slave station 62 at the same time, these detected signals are not transmitted to the master station. 61 is not received at the same time. This is because the optical fiber line 63 has a propagation delay time, and the time for the detection signal to reach the master station 61 from the slave station 62 depends on the position where the slave station 62 is provided. Further, each slave station 62 has a different structure for performing multiplex communication, and the time delay of the circuit operation also differs depending on the slave station 62. Therefore, as shown in FIG. 8, for example, the detection signals a, b,..., N transmitted from the slave stations 62a, 62b,.
.., Tn are recognized by the master station 61. That is, in the conventional telemetry communication device, the detection time of the event cannot be measured relatively accurately between the slave stations 62.

[0007] In addition, the slave station 6 by the time division multiplex communication system.
When the detection signal is transmitted from 2 to the master station 61, each slave station 62 is assigned only a limited time. In other words, each slave station 62 must pass a transmission waiting time in order to communicate with the master station 61, and the master station 61 cannot access each slave station 62 at the same time. Therefore, each sensor 65
Are detected at the same time, the master station 61 cannot receive the detection signals of the respective slave stations 62 at the same time. Therefore, in the time-division multiplex communication system, it has been conventionally difficult to grasp the detection time of an event occurring in each slave station 62 relatively accurately. In order to solve such a problem, it is conceivable to provide a clock in each slave station 62 and transmit the time itself at which a signal is detected by the sensor 65 to the master station 61. However, the time of each clock provided in each slave station 62 does not always coincide with each other. Therefore, conventionally, each slave station 6
Also, the occurrence time of the event occurring in No. 2 could not be detected relatively accurately. When the event is a lightning surge current or the like detected on the order of μsec, each slave station 62
The slight time difference that occurs in the timepiece of this type is also a big problem.

[0008] In addition, the slave station 6 by frequency division multiplex communication.
When the detection signal is transmitted from 2 to the master station 61, both the master station 61 and the slave station 62 require high-frequency modems. Further, in the code division multiplex communication, several codes are used for each slave station, so that a code generation circuit differs for each slave station, and a circuit for determining each of these codes is required in the master station 61. Further, in wavelength division multiplex communication, several types of signal wavelengths are used for each slave station, so that a light source emitting light at these several types of wavelengths is required. Furthermore, transmission line systems such as the optical fiber line 63 and the optical coupler 64 need to have characteristics that do not have wavelength dependency. Therefore, even if any of these multiplex communication systems is used, the circuit configuration of the communication device becomes complicated and the device price becomes expensive.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a primary modulation means for modulating a carrier wave by a transmission signal to generate a primary modulation signal and a clock are provided. A master-side PN code generating means for generating a PN code circulating through a predetermined number of different states by changing the state every time, and further modulating the primary modulation signal with the master-side PN code to produce a secondary modulation signal , A master station having signal sending means for sending the secondary modulated signal, a signal receiving means for receiving the secondary modulated signal and outputting a received signal, the same code as the master station PN code Slave unit PN code generating means for generating a series slave unit PN code,
Synchronizing means for synchronizing the phase of the code with the phase of the master-side PN code included in the received signal, demodulating means for demodulating the transmitted signal from the synchronized received signal, detecting an event and transmitting the detection to the master station And a plurality of slave stations each having a measuring means, each of the slave stations includes a latch means for latching a slave station-side PN code at a timing when an event is detected, and the measuring means includes the slave means. Office PN
The master station transmits the code as a detection signal to the master station, and the master station determines the temporal correlation between the slave station PN code sent from the slave station and a specific value used as a reference for the slave station PN code generation means. And a time calculating means for calculating an event detection time from the elapsed time from an elapsed time from a reference timing having an event detection timing.

Further, the connection control of the communication line between the master station and each of the plurality of slave stations is performed by a polling method.

The master station includes a third PN code generating means for generating a PN code of the same code sequence as the master station PN code;
Synchronizing means for transmitting the phase of the PN code generated by the third PN code generating means to the slave station and synchronizing with the phase of the returned master station PN code, and master station PN code generating means are generated. Master station PN code and master station PN returned from slave station
Latch means for latching, at a predetermined timing, PN codes generated by third PN code generation means synchronized with the codes, and a signal between the master station and the slave station based on the phase difference between the PN codes latched by the latch means. And a delay time measuring means for calculating a propagation delay time.

Further, the master station is provided with distance calculating means for calculating a product of a propagation delay time measured by the delay time measuring means and a signal propagation speed in a communication path between the master station and the slave station. It is assumed that.

[0013]

When an event is detected in each slave station, the slave station side PN code at this detection timing is latched by the latch means.
It is transmitted to the master station by the measuring means. In the master station, an elapsed time from a reference timing having an event detection timing is obtained based on a temporal correlation between the received slave station PN code and a specific value used as a reference of the slave station PN code generating means. . Further, the event detection time is obtained from the elapsed time.

At this time, the slave PN code latched at each slave station at the event detection timing is phase-synchronized with the same master PN code transmitted from the master station. For this reason, the phases of the slave station PN codes are the same between the slave stations. Therefore, the event detected by each slave station is the phase synchronization of the slave station side P
It is detected based on the same timing determined by the N code.

Further, the event detection timing is determined by the slave station PN.
Since the code is transmitted from the slave station to the master station and the detection timing itself is not transmitted, a time division multiplex communication method such as a polling method can be used for the multiplex communication.

Further, the master station is provided with a delay time measuring means for obtaining a signal propagation delay time with the slave station, so that the event detection time is corrected by the propagation delay time.

Further, a distance calculation means is provided in the master station, and the product between the propagation delay time and the signal propagation speed in the communication path is obtained, thereby obtaining the distance between the master station and each slave station.

[0018]

Next, an embodiment in which the telemetry communication device according to the present invention is applied to a system for locating a lightning point on a transmission line will be described.

FIG. 2 shows an image of this system.

Each steel tower 1 is installed on the ground 2 at an average interval of 300 m per span. An optical fiber composite overhead ground wire (OPGW) is stretched between these towers 1. That is,
An overhead ground wire 3 made of a conductive wire and a single-core optical fiber line 4 are bridged between the towers 1. Also,
Each of the towers 1 is separated from the slave stations 5 by a predetermined interval every five spans on average.
Is provided. The tower 1 provided with each of these slave stations 5
The unit is provided with a lightning surge sensor 6. As shown, when a lightning surge occurs, a lightning surge current propagates to the overhead ground wire 3 on both sides of the point to be lightned. When each of the slave stations 5 detects this lightning surge current, it sends this detection signal to the optical fiber line 4 via the optical coupler 8. This detection signal is collected by the master station 7 as transmission line maintenance monitoring information.

The connection control of the communication line between the master station 7 and each slave station 5 is performed by a polling method. That is, the relationship between the master station 7 and each slave station 5 is schematically shown in FIG. 3A, and the communication between the master station 7 and each slave station 5 is shown in FIG. , (C). FIG. 9B shows the timing of the master station polling command. The master station 7 always sends the PN code to each slave station 5, and multiplies the polling command to each slave station 5 by the hatched timing shown. FIG. 3C shows the timing of the slave station response, and each slave station 5 responds to the command from the master station 7 at the illustrated timing.

FIG. 1A is a block diagram showing the internal configuration of the master station 7. As shown in FIG. A coder (coder) 11 modulates a carrier with a transmission signal to generate a primary modulation signal, and outputs this signal serially. The M-sequence generation circuit 12 is connected to the master station side PN.
Generate a sign. A linear feedback shift register (LFSR) 13 is supplied with a clock of an oscillator (OSC) 15 frequency-divided by a frequency divider (Δm) 14. The internal configuration of the LFSR 13 is shown in FIG. 4A and includes an n-stage shift register 13a and an adder 13b. Each of the shift registers 13a1 to 13an includes a frequency divider 1
Every time a clock is input from the register 4, the stored contents are shifted to the register on the right side.
Output the series. This M-sequence output is "0", "1"
And appears repeatedly at a period of 2 @ n -1. In other words, there are 2 @ n data states stored in each of the n-stage shift registers, and when one state of all zeros is subtracted therefrom, there are 2 @ n -1 states. Also, the number of shifts and LF
The contents stored in each shift register 13a of the SR 13 have a one-to-one correspondence. Therefore, by knowing the storage state of the LFSR 13, the number of input clocks to the LFSR 13 can be known. FIG. 7B shows the M-sequence output arranged on a circle. In order to make one round of the circle from the starting point S, 2n-1 bits (g1, g2..., Gk) are used.
Elapses. Here, k = 2 @ n -1, information bit string A (g1, g2... Gn), information bit string B
(G2, g3 ..., gn + 1) ... are the shift registers 13a1
It corresponds to the stored contents of ~ 13an. That is, the M-sequence generation circuit 12 changes the state each time a clock is applied, and generates a PN code that cycles through a predetermined number of different states.

The primary modulation signal output from the coder 11 shown in FIG. 1A is multiplied by the master station PN code in a multiplier 16 and subjected to secondary modulation. These processes are performed on the bus 1
A processor 18 connected through 7
And using a memory 19. A host computer or the like is connected to the interface (I / F) circuit 20. The secondary modulation signal is electric light (E / O)
The electric signal is converted into an optical signal by the converter 21 and sent to the optical fiber line 4 via the optical coupler 8. Further, the narrow band signal which is propagated through the optical fiber line 4 and received by the master station 7 is converted from an optical signal into an electric signal by the O / E converter 22, and is decoded by the decoder 23 and the delay lock loop circuit (DL).
L) 24. The decoder 23 demodulates the serially input narrowband received signal and decodes the signal from the slave station 5. The DLL 24 is provided with a master station 7 described later.
When measuring the optical propagation delay time between the slave station 5 and the slave station 5,
This is a circuit for synchronizing with the PN code returned from.

FIG. 1B is a block diagram showing the internal configuration of the slave station 5. As shown in FIG. The signal received from master station 7 is first O / E
The electric signal is returned to the electric signal by the converter 31. And a multiplier 32
a and a band-pass filter (BPF) 33a correlate with the PN code sequence P on the slave station side.
Is demodulated. At this time, the master station PN included in the received signal
The phases of the code and the slave station PN code are always synchronized by the DLL 35.

That is, P which is advanced by a half-chip phase as compared with the slave station-side PN code sequence P output from the LFSR 36.
N code sequence E, PN code sequence L with half chip phase delay
Are multiplied by the received signals in multipliers 32b and 32c, respectively. The multiplication result is integrated by the BPFs 33b and 33c, so that a correlation between the received signal and each of the code sequences E and L is obtained. Each of the correlated signals is further passed through an envelope detection circuit (ABS) 37b, 37c, and a difference between them is obtained in an adder 38. This difference is integrated by a low-pass filter (LPF) 39, and a voltage corresponding to this difference is input to a voltage controlled oscillator (VCO) 40. VCO4
0 outputs a frequency signal corresponding to the input voltage. This signal is frequency-divided by a frequency divider (分 m) 41,
6 given. The LFSR 36 responds to this signal input,
The phase of the generated PN code sequence on the slave station is shifted to match the phase of the PN code sequence on the master station. These processes are performed using a processor 43 and a memory 44 connected to the bus 42.

The output of the LFSR 36 is provided to the latch circuit 50. When the lightning surge current is detected by the lightning surge sensor 6, the LFS at the detection timing is detected.
The contents of the register R36 are latched by the latch circuit 50. Signals from other transmission line maintenance / monitoring sensors are input to the interface (I / F) circuit 45. The analog measurement information from the outside is converted from an analog signal to a digital signal by the A / D converter 46. The coder 47 converts a signal transmitted serially from the slave station 5 to the master station 7 into a narrow band signal. This narrow band signal is transmitted through switch 48 to E /
The signal is supplied to the O converter 49, converted into an optical signal, and transmitted to the optical fiber line 4. Also, a reply changeover switch 48
Is switched from the b side to the a side when the optical propagation delay time between the master station 7 and the slave station 5 described later is measured.

Note that a CMI code is used as an optical transmission code, and is transmitted at a speed four times that of one chip of a PN code. That is, each of the frequency dividing circuits 14, 30, and 41 divides the frequency by four. This optical transmission code may use Manchester or scramble NRZ. The command transmission from the master station 7 to the slave station 5 is performed by multiplying the PN code by 1 bit with a length of 24 times one chip of the PN code. Therefore, in the DLL 35 of the slave station 5, the 4 × 1/1 extracted by the CMI codec is used.
Digital synchronization is achieved using the clock of the chip.

Each of the E / O converters 21 and 49 and each of the O / E converters 22 and 31 are configured using laser diodes having the same wavelength. In this embodiment, multiplex communication is performed in a time-division manner by the above-described polling method, but the wavelength is set for transmission from the master station 7 to the slave station 5 and from the slave station 5 to the master station 7 on the single-core optical fiber line 4. You may comprise so that it may change. Further, the optical fiber line 4 may be constituted by a two-core optical fiber for each communication direction.

In such a configuration, when the lightning surge current is detected by the sensor 6 and the contents of the shift register of the LFSR 36 are latched by the latch circuit 50, the contents of the shift register are transferred from the slave station 5 to the master station 7 by the coder 47. Sent to

On the master station 7 side, the contents of the shift register sent from the slave station 5 are referred to as table values stored in the ROM 51 in advance. In the table of the ROM 51,
Temporal correlation between the number of input clocks to the LFSR 36 (a specific value as a reference of the LFSR 36) and the contents of the shift register of the LFSR 36 corresponding to the number of input clocks (PN code on the slave station) based on a certain timing Is stored. As described above, the master station PN code is always sent from the master station 7 to each slave station 5, and the slave station PN code generated by the LFSR 36 of each slave station 5 is, as described above, the master station PN code.
It is synchronized with the code. That is, the contents of the shift register of the LFSR 36 in each slave station 5 change at the same timing as the contents of the same shift register of the LFSR 13 in the master station 7. The contents of this register from the slave station 5 latched by the latch circuit 50 are referred to the above table, so that the elapsed time t from a certain reference timing can be known. That is, as shown in FIG. 5A, the contents of the shift register at each timing (g1, g2... Gn), (g2, g3.
Are, for example, elapsed times t1, t2,.
Correspond one-to-one. Then, by inputting the contents of this shift register, for example, (g1, g2..., Gn) into the ROM 51 shown in FIG. 3B as an address, the elapsed time ti, for example, t1 is output as data. Knowing this elapsed time, the occurrence time of the lightning surge current detected by the sensor 6 of the slave station 5 can be measured.

As described above, in this embodiment, the slave station PN latched by each slave station 5 at the lightning surge detection timing.
The code is in phase synchronization with the same master station PN code sent from the master station 7. Therefore, the phases of the slave station PN codes are the same between the slave stations 5. For this reason, the lightning surge detected by each slave station 5 is detected based on the same timing determined by the slave station side PN code synchronized in phase. Therefore, the lightning surge detection time obtained by the master station 7 from the latched slave station PN code does not include an error between the slave stations 5. That is, the detection time of the lightning surge detected by each of the slave stations 5 is relatively accurately measured between the slave stations 5.

The detection timing of the lightning surge is conventionally transmitted as the detection timing itself. In the present embodiment, the detection timing is transmitted from the slave station 5 to the master station 7 as the slave station PN code. . For this reason, according to the present embodiment, it is possible to employ the polling method described above for multiplex communication. Therefore, each slave station 5 can have the same configuration, and the master station 7 and each slave station 5 can be configured relatively easily as compared with other multiplex communication systems.
Therefore, according to the present embodiment, it is possible to reduce the price of the telemetry communication device.

The PN code is always transmitted from the master station 7 to the slave station 5 in order to time the lightning surge detection time. At this time, the PN code is determined according to the distance between the master station 7 and the slave station 5. A propagation delay due to the optical fiber line 4 and an operation delay of each circuit are added. Therefore, in this embodiment, the measurement time is corrected as follows.

The correction of the measurement time due to the operation delay of each circuit can be performed by subtracting the previously measured delay time from the measurement time because the operation delay can be measured in advance when the device is manufactured.

In correcting the measurement time due to the light propagation delay, first, a command is sent from the master station 7 to the slave station 5,
The switch 48 in the slave station 5 is switched from the b side to the a side. Next, as shown in FIG. 6, the master station side PN code is transmitted from the LFSR 13 of the M sequence generation circuit 12 in the master station 7 to the slave station 5. At this time, the command input from the coder 11 to the multiplier 16 is kept constant. The PN code on the master station side is the O / E converter 31 and the E / O converter 4 on the slave station 5 side.
It returns to the master station 7 via 9. In this embodiment, the master station 5
The DLL 24 shown in FIG. 1 is also provided therein. This D
LL24 forms a baseband delay lock loop, and sets the phase of the M-sequence code generated in LFSR25 to
The phase is matched with the phase of the returned master station PN code. Here, the M-sequence code generated by the LFSR 25 has the same code sequence as the M-sequence code generated by the LFSR 13 in the M-sequence generation circuit 12.

For example, the n-th stage and the n-2
The output of the shift register at the stage and the received master station PN code are multiplied by multipliers 26a and 26b, respectively. This multiplication result is a low-pass filter (LPF) 27a,
The correlation between the master station PN code received from the slave station 5 and the output of each shift register is obtained by being integrated by passing through b. The adder 28 calculates the difference between these correlations, and calculates VC
O29 outputs a frequency signal of a voltage corresponding to this difference. This frequency signal is frequency-divided by a frequency divider (÷ m) 30,
It is input to the LFSR 25. The LFSR 25 shifts the phase of the generated PN code according to the input signal, and synchronizes with the phase of the received PN code from the slave station 5.

When the contents of the register of the LFSR 13 in the M-sequence generating circuit 12 become, for example, a bit information sequence A (g1, g2,..., Gn), the processor 18 of the master station 7
Register contents of SR13 and LFSR in DLL24
The contents of the register 25 are latched in the latch circuit 52 (see FIG. 6). The register contents of the LFSR 25 in the DLL 24 include the light propagation delay of the optical fiber line 4.
Therefore, the difference between the contents of the registers of the latched LFSR 13 and LFSR 25 is obtained, and the difference is converted into time, whereby the light propagation delay time due to the optical fiber line 4 can be obtained. This optical propagation delay time corresponds to the round trip time of the master station side PN code between the master station 7 and the slave station 5. Therefore, by subtracting the round trip time from the measured time as described above, the light propagation delay time previously added to the measured time can be removed. That is, according to this embodiment, the lightning surge detection time is corrected by the propagation delay time, and an accurate detection time is obtained.

By knowing the light propagation delay time, the distance between the master station 7 and the slave station 5 can be measured. That is, by taking 1/2 of the above-mentioned round trip time, the one-way light propagation delay time τ can be obtained. By multiplying the time τ by the light propagation speed c in the optical fiber line 4, the distance L between the master station 7 and the slave station 5 can be obtained. For this reason, if this distance is registered in the host computer, it is possible to immediately determine at which point the slave station 5 is located at the time of maintenance or replacement of each slave station 5. That is, the distance L between the master station 7 and each slave station 5 is automatically measured, which can be used for maintenance of each slave station 5 and the like.

In the above embodiment, the case where the present invention is applied to a system for locating a lightning point of a transmission line has been described, but the present invention is not limited to this. For example, the present invention can be applied to a system for measuring the detection time of a seismic wave such as a p-wave and an s-wave at each of the observation points dispersedly arranged. In this case, the same effect as in the above embodiment can be obtained.

[0040]

As described above, according to the present invention, the slave station PN code latched at the event detection timing in each slave station is synchronized with the same master station PN code transmitted from the master station. Therefore, the phases of the slave station side PN codes are the same between the slave stations. For this reason, the event detected by each slave station is detected based on the same timing determined by the slave station side PN code synchronized in phase. Therefore, the event detection time obtained at the master station from the latched slave station PN code does not include an error between the slave stations. That is, the detection time of the event detected in each slave station is relatively accurately measured.

The event detection timing is determined by the slave station side PN.
Since the code is transmitted from the slave station to the master station and the detection timing itself is not transmitted, a time division multiplex communication method such as a polling method can be used for the multiplex communication. Therefore, each slave station can have the same configuration, and can be configured more easily than other multiplex communication systems. Therefore, it is possible to reduce the price of the communication device.

Further, by providing the master station with a delay time measuring means for obtaining a signal propagation delay time with the slave station, the event detection time is corrected by the propagation delay time. Therefore, an accurate event detection time is obtained.

Further, a distance calculation means is provided in the master station, and the product between the propagation delay time and the signal propagation speed in the communication path is obtained, thereby obtaining the distance between the master station and each slave station. For this reason, the position of each slave station can be known, which can be used for maintenance of each slave station.

[Brief description of the drawings]

FIG. 1 is a block diagram showing respective configurations of a master station and a slave station of a telemetry communication device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating a lightning target location system to which the present embodiment is applied;

FIG. 3 is a diagram showing a schematic configuration and a signal timing chart of a polling communication system adopted as a multiplex communication system of the embodiment.

FIG. 4 shows a linear feedback shift register (LFS).
3 is a diagram illustrating an internal configuration and functions of R). FIG.

FIG. 5 is a diagram for explaining the principle of obtaining the elapsed time from the reference timing of the event detection timing from the correlation between the slave station PN code and the number of input clocks to the slave station PN code generation means.

FIG. 6 is a block diagram showing an outline of delay time measurement for obtaining an optical propagation delay time between a master station and a slave station.

FIG. 7 is a block diagram showing a conventional telemetry communication device.

FIG. 8 is a graph showing event detection timing detected by a conventional telemetry communication device.

[Explanation of symbols]

11, 47 ... coder 12 ... M-sequence generation circuit 13, 25, 36 ... linear feedback shift register (LFSR) 14, 30, 41 ... frequency divider (@m) 15 ... oscillator (OSC) 16, 26a, b, 32a .About.c Multipliers 17, 42 Bus (BUS) 18, 43 Processor (Processor) 19, 44 Memory (Memory) 20, 45 Interface circuit (I / F) 21, 49 Electro-optical converter (E) / O) 22, 31 ... photoelectric converter (O / E) 23, 34 ... decoder (Decoder) 24, 35 ... delay lock loop (DLL) 27a, b, 39 ... low-pass filter (LPF) 28, 38 ... addition Units 29, 40: Voltage-controlled oscillators (VCO) 33a to c: Band-pass filters (BPF) 37b, c: Envelope detection circuit (ABS) 48: Reply switch 50 52 ... latch circuit 51 ... read only memory (ROM)

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI H02H 3/00 H02H 3/00 Q 7/26 7/26 F H02J 13/00 301 H02J 13/00 301A (72) Inventor Ogawa Rika 4-1, Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside the System Research Laboratories of Tokyo Electric Power Company (72) Inventor Yoshiaki Sugano 2-8-1, Tamagawa, Ota-ku, Tokyo Inside Osaki Electric Industry Co., Ltd. (72 ) Inventor Naoto Fujisaka 2-8-1 Tamagawa, Ota-ku, Tokyo Osaki Electric Industry Co., Ltd. (72) Kunio Satodate 2-8-1 Tamagawa, Ota-ku, Tokyo Osaki Electric Industry Co., Ltd. 72) Inventor Keisuke Morikubo 2-8-1, Tamagawa, Ota-ku, Tokyo Inside Osaki Electric Industry Co., Ltd. (72) Inventor Toshio Obizu 2-2-1 Tamagawa, Ota-ku, Tokyo Large Inside Electric Industry Co., Ltd. (72) Inventor Isao Utsugi 2-81-1, Tamagawa, Ota-ku, Tokyo Inside Osaki Electric Industry Co., Ltd. (56) References JP-A-53-47218 (JP, A) JP-A-1 -242974 (JP, A) JP-A-4-145379 (JP, A) JP-A-6-58979 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/40 G01R 31/08 H02H 3/00 H02H 7/26 H02J 13/00 301

Claims (4)

(57) [Claims] 1. A primary modulation means for modulating a carrier by a transmission signal to generate a primary modulation signal, and a pseudo-noise code whose state changes each time a clock is applied and which cycles through a predetermined number of different states. Generating means for generating the pseudo-noise code on the master station side; secondary modulation means for further modulating the primary modulation signal with the pseudo-noise code on the master station side to generate a secondary modulation signal; and transmitting the secondary modulation signal A master station having signal transmitting means for receiving the second modulated signal and outputting a received signal; and generating a pseudo-noise code on the slave station side having the same code sequence as the pseudo-noise code on the master station side. Slave station side pseudo noise code generation means, synchronization means for synchronizing the phase of the slave station side pseudo noise code with the phase of the master station side pseudo noise code included in the received signal, and Demodulation means for demodulating a transmission signal A measuring device for detecting a certain event and transmitting the detection to the master station, comprising: a plurality of slave stations, wherein each of the slave stations is a slave station at a timing when the event is detected. Latch means for latching a pseudo-noise code on the side, the measuring means transmits the pseudo-noise code on the slave station side as a detection signal to the master station, and the master station transmits the slave station from the slave station. Elapsed time calculation means for calculating an elapsed time from a reference timing at which the event is detected based on a temporal correlation between a side pseudo noise code and a specific value used as a reference of the slave station side pseudo noise code generation means. And a time calculating means for obtaining a detection time of the event from the elapsed time. 2. The remote measurement communication device according to claim 1, wherein connection control of the communication line between the master station and each of the plurality of slave stations is performed by a polling method. 3. The pseudo-noise code generating means for generating a pseudo-noise code having the same code sequence as the master-station-side pseudo-noise code, and the third pseudo-noise code generating means generates the pseudo-noise code. Synchronization means for transmitting the phase of the pseudo-noise code to the phase of the master-side pseudo-noise code returned by transmitting to the slave station; and the master-side pseudo-noise code generated by the master-side pseudo-noise code generation means. Latch means for latching, at a predetermined timing, the noise code and the pseudo-noise code generated by the third pseudo-noise code generation means synchronized in phase with the master-side pseudo-noise code returned from the slave station; 3. The remote control device according to claim 1, further comprising: a delay time measuring means for calculating a signal propagation delay time between the master station and the slave station from a phase difference between the pseudo noise codes latched by the means. Measurement communication equipment Place. 4. The distance calculation means for calculating a product of a propagation delay time measured by the delay time measurement means and a signal propagation speed in a communication path between the master station and the slave station. The telemetry communication device according to claim 3, wherein: