CN203554466U - power line information monitoring device - Google Patents
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- CN203554466U CN203554466U CN201320702384.2U CN201320702384U CN203554466U CN 203554466 U CN203554466 U CN 203554466U CN 201320702384 U CN201320702384 U CN 201320702384U CN 203554466 U CN203554466 U CN 203554466U
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Abstract
The utility model discloses a power line information monitoring device, comprising a reception electromagnetic coupler, an analog-to-digital converter ADC, a programmable gate array FPGA, a microprocessor DSP and a display. The reception electromagnetic coupler receives communication information on a power line and sends the communication information to the analog-to-digital converter ADC. The analog-to-digital converter ADC carries out A/D conversion over the communication information and then sends the converted communication information to the programmable gate array FPGA. The programmable gate array FPGA carries out filtering and digital frequency converting over the received communication information and then sends the processed communication information to the microprocessor DSP which is used for determining that whether communication exists or not. The power line information monitoring device can monitor information of information processing equipment transmitted by the power line, timely finds abnormal communication, and prevents classified information from being lost or leaked or important information equipment from being attacked by "pre-embedded" information bombs.
Description
Technical field
The utility model relates to a kind of power line information monitoring device, is mainly used in 220V low-voltage power line, to possible, utilizes power line carrier communication to carry out as covert communications channel the behavior that technology steals secret information, divulges a secret effectively to monitor.
Background technology
Power line is current the most common, coverage rate is the widest a kind of physical media, and the power network consisting of it is one and is close to natural physical network.Utilize the resource potential of power network, do not affecting under the prerequisite of electric energy transmitting, power delivery network and communication network being united two into one, make it to become the another communication network after relay letter, phone, wireless telecommunications, satellite communication, is a focus of scientific and technical personnel's research of technique both at home and abroad for many years.Electric line carrier communication produces under this background, and it realizes data transmission and information exchange using power network as channel.Power line, as the transmission medium of carrier signal, is unique wire communication mode that does not need track investment.As an emerging application of mechanics of communication, power carrier communication technology is take its tempting prospect and potential great market and as World Focusing.
At present, the reference carrier frequency of arrowband PLC is different in country variant, different regions, the U.S. is 50kHz～450kHz, Europe is that (95kHz is following for access communications for 3kHz～148.5kHz, 95kHz is above for indoor communication), China is 3kHz～500kHz, and that IEC61000-3-8 stipulates is 3kHz-500kHz.Broadband power carrier communication, various countries are also different, in the U.S., are 4MHz～20MHz (HomePlug1.0 version), are mainly used in indoor.Europe ETSI is defined as 1.6MHz～10MHz (access communications) and 10MHz～30MHz (indoor communication), and the CENELEC of European Union standard separation is 13MHz.
And China takes to the research of electric line carrier communication technology from the fifties in last century.After the initial stage nineties, the demand of power line carrier technology is along with China's expanding economy further expands.At present, this technology starts to be applied to the fields such as household automation, remote meter reading, broadband access network.Expert introduction, if disturb industrial circle large, difficult wiring will realize automation control at some, adopts power carrier communication mode can reach the effect of getting twice the result with half the effort, and therefore, power network is called again " Kingsoft of not excavated ".A power line is exactly one " data wire ", and in low pressure (220V) field, PLC technology is first for the control of loading, remote meter reading and household automation, and transmission rate is generally 1200bps or lower, is called low speed PLC.The power line communication technology of low-voltage power line transmission rate more than 1Mbps that utilize of carrying out both at home and abroad is in recent years high speed PLC, is applied, and has the gesture of extensive popularization.The epoch that reach its maturity at power line carrier communication, because most data storages, treatment facility are (as computer, printer, photocopier, facsimile machine, the Digit Control Machine Tool of factory etc.) too busy to get away power line, if power line carrier, PLC channel is a convert channel for setting up known to us not, the information security of all data of these equipment room processing is just without Mi Kebao so, and this will bring great potential safety hazard.Low-voltage power line is divulged a secret and is had three large approach, the one, by power carrier, surf the Net, its data are easy to be intercepted by others, intercept people as long as add intercepting equipment by the arbitrfary point of power line, just obtaining information easily, much easier compared with the Internet line intercepting, and, be not easy others and find.The 2nd, external hostile force, completely likely, pre-buried integrated power line carrier, PLC chip in equipment, by power line, intercept my party, political affairs, army's national security information, or intercepting data in process equipment, broken ring production etc., can realize by this approach.The 3rd, computerized information passes through power line radiation, reveals useful information.
Applicant has proposed a kind of power line information leakage prevention blocking-up method and device thereof on 05 21st, 2012, application number " 201210158089.5 ", and open day is on 09 19th, 2012, this technology is mainly for power line radiation leaks useful information.But along with the development of electric power carrier communication technology, the network security based on power circuit also needs further reinforcement.
Summary of the invention
The purpose of this utility model is to overcome the problems referred to above that existing power-line carrier communication exists, a kind of power line information monitoring device is provided, the utility model can pass through power line transmission information by monitoring information treatment facility, find in time improper communication, prevent that secret leaking or important information equipment from suffering the attack of " pre-buried " information bomb.
For achieving the above object, the technical solution adopted in the utility model is as follows:
A kind of power line information monitoring device, it is characterized in that: comprise and receive electromagnetic coupler, analog to digital converter ADC, programmable gate array FPGA, microprocessor DSP and display, described reception electromagnetic coupler sends to analog to digital converter ADC after receiving the communication information on power line, analog to digital converter ADC sends to programmable gate array FPGA after communication information A/D is changed, and on-site programmable gate array FPGA carries out the communication information receiving to send to the microprocessor DSP for judging whether to exist communication behavior after filtering and digital frequency conversion processing.
Described programmable gate array FPGA is comprised of digital filter processor and baseband processor, digital filter processor carries out the communication information receiving to send to baseband processor after filtering processing, and baseband processor carries out sending to microprocessor DSP after digital frequency conversion processing to the communication information receiving.
The utility model also comprises frequency point scanning match circuit, and described frequency point scanning match circuit is receiving between electromagnetic coupler and analog to digital converter ADC.
Described reception electromagnetic coupler comprises the arrowband coupling circuit and the broadband coupling circuit that are arranged in parallel, and arrowband coupling circuit is used for receiving arrowband power line carrier, PLC signal, and broadband coupling circuit is used for receiving broadband power carrier communication signal.
The utility model also comprises power supply and electric power controller, and described power supply is connected to each circuit, for provide ± 15V, ± 12V, ± 9V, ± 5V, 3.3V and 1.2V power supply.
On described microprocessor DSP, be provided with 1 RS232 mouth and 1 USB mouth, RS232 mouth is for device networking monitoring, and USB mouth is for being connected intercommunication data with PC.
Employing the utility model has the advantage of:
One, adopt after the utility model, arrowband, broadband signal in whole 1KHz～80MHz band limits can be caught simultaneously; On power line, be no matter to have individually or simultaneously multiple frequency communication, can exhaustively carry out Real-Time Monitoring.
Two, in the utility model, can detect from the power carrier signal of the whole frequency range of 1KHz ~ 80MHz, include all frequency ranges and the frequency of the power line carrier, PLC of current technology.
Three,, in the utility model, by signature analysis, can detect the key character information such as the communication frequency (frequency range), signal strength signal intensity, Frame length, Frame interval of power line carrier, PLC.
Four, in the utility model, the characteristic information of extraction, modulation system that can analytical characteristic signal; And in the utility model, can pass through initiatively transmission information, then the mode of receiving and analyzing, find whether to have on power line the existence of other equipment.
Five, in the utility model, adopt the SD card of large color screen liquid crystal touch screen and large buffer memory, can show and store detection signal signature waveform and significant data, adopt RS232 interface, can many table apparatus interconnected, the communication information on networking monitoring power line, adopt USB interface to be connected with PC, can, by detecting transfer of data to PC processing, also can to this, install transformation parameter by PC, the operation of control device simultaneously.
Six, in the utility model, adopt Modeling Calculation, be by means of experiment or measure a collection of discrete data, by the abundant observation and analysis of data, obtain the contained information of data, disclose the inner link between variable, and select suitable mathematical expression to carry out matching to the relation of variable, set up empirical model, pass through empirical model, just energy analytical calculation information characteristics, convenient and swift, real-time; For the Real-Time Monitoring of power line communication lays the foundation.
Seven, the utility model extraction correlated characteristic contrasts, and can set up a large amount of property data bases, extracts correlated characteristic and contrasts with it, is conducive to improve and optimize, and improves constantly accuracy and the rapidity of feature identification.
Accompanying drawing explanation
Fig. 1 is the utility model monitoring device structural principle schematic diagram.
Embodiment
Embodiment 1
A kind of power line information monitoring device, comprise and receive electromagnetic coupler, analog to digital converter ADC, programmable gate array FPGA, microprocessor DSP and display, described reception electromagnetic coupler sends to analog to digital converter ADC after receiving the communication information on power line, analog to digital converter ADC sends to programmable gate array FPGA after communication information A/D is changed, on-site programmable gate array FPGA carries out the communication information receiving to send to microprocessor DSP after filtering and digital frequency conversion processing, and microprocessor DSP judges whether to exist communication behavior.
Described programmable gate array FPGA is comprised of digital filter processor and baseband processor, digital filter processor carries out the communication information receiving to send to baseband processor after filtering processing, and baseband processor carries out sending to microprocessor DSP after digital frequency conversion processing to the communication information receiving.
The utility model also comprises frequency point scanning match circuit, and described frequency point scanning match circuit is receiving between electromagnetic coupler and analog to digital converter ADC, for play frequency selection effect from low frequency to high frequency frequency sweep.The signal receiving from coupling circuit is a wide band signal, and frequency point scanning match circuit will therefrom be selected the carrier signal of a certain frequency (section) that will receive.Meanwhile, mistake by force or excessively, such signal all will carry out suitable decay or amplification sometimes for the signal that coupling circuit receives.That is to say, the signal demand receiving from coupling circuit carries out certain preliminary treatment, just can deliver to ADC and carry out digitlization conversion process, and this circuit is comprised of mixing and filtering circuit and signal programmable amplifying circuit, the prior art of application.
Described reception electromagnetic coupler comprises the arrowband coupling circuit and the broadband coupling circuit that are arranged in parallel, and arrowband coupling circuit is used for receiving arrowband power line carrier, PLC signal, and broadband coupling circuit is used for receiving broadband power carrier communication signal.This main circuit will be by power supply coupling transformer, filter, Anti-surging diode, the main one-tenth of overvoltage/current foldback circuit, the prior art of application.
The utility model also comprises power supply and electric power controller, and described power supply is connected to each circuit in device, for provide to device ± 15V, ± 12V, ± 9V, ± 5V, 3.3V and 1.2V power supply.Electric power controller is for carrying out safe isolation, noise isolation, short-circuit protection, overvoltage protection, overcurrent protection, boosting inverter, decompression transformation, screen protection etc. to device.
In the utility model, described microprocessor DSP provides 1 RS232 mouth, 1 USB mouth; RS232 mouth is for device networking monitoring, and USB mouth is for being connected intercommunication data with PC.
In the utility model, display screen is for showing, for example large color screen liquid crystal touch screen is used for showing detection data or signal waveform, and touch-screen is for parameter setting, the human-computer dialogue of device.
Embodiment 2
Method when the present embodiment is applied to power line information monitoring to the utility model describes.
A kind of power line information monitoring method, comprises the steps:
A, when having power line carrier, PLC communication on power communication line, receive this power line carrier, PLC information, and carry out electronic tuning process and A/D change;
B, the digital signal after A/D conversion is carried out to filtering and digital frequency conversion processing;
C, signal after treatment is carried out to Modeling Calculation restore digital baseband signal, baseband signal is carried out to correlated characteristic extraction, according to the correlated characteristic extracting, judge on power communication line, whether there is communication behavior.
In described a step, coupling circuit receives arrowband and the broadband power carrier communication information on power communication line, and sends to analog to digital converter and carry out A/D conversion.
In described b step, the digital signal after A/D conversion sends to on-site programmable gate array FPGA, and on-site programmable gate array FPGA carries out filtering and digital frequency conversion processing by the communication information receiving, and is sent to microprocessor DSP.
In described c step, microprocessor DSP Modeling Calculation comprises the steps:
C1, suppose that the baseband signal of transmission information on power communication line is S (t):
S (t)=[1+k
am (t)] cos (ω
it+ θ
i) (formula 1)
In formula: k
afor the modulation index of amplitude-modulated wave, m (t) is modulation signal, ω
ifor the angular frequency of input signal, θ
ifor the phase angle of input signal;
C2, the communication information decay to A (t) in power communication line channel, and the noise of introducing in power communication line transmission is N (t), the signal P of power communication line itself
l(t) be:
P
l(t)=B cos (2 PI 50t+ θ
i2) (formula 2)
In formula, B is power communication line signal strength signal intensity and the ratio that is linked into the communication signal strength on power communication line, and PI is circumference ratio constant, θ
i2for the phase place of civil power, t is the time;
C3, the signal R (t) that receives at acceptance point is
R (t)=A (t) [1+k
am (t)] cos (ω
it+ θ
i)+N (t)+B cos (2PI 50t+ θ
i2) (formula 3)
Statistical analysis obtains A (t) and the N (t) in formula by experiment, by filter, filters Bcos (2PI50t+ θ i2), calculates that to restore digital baseband signal be S (t) by reverse operation.
The method of A (t) parameter is obtained in statistical analysis by experiment: in the power circuit of a topological structure, one end at power circuit couples a signal on power circuit by electromagnetic coupled apparatus with signal generator, at the other end of power circuit, signal is sent to frequency spectrograph analysis by receiving after electromagnetic coupled apparatus is processed.
For example, in one end of power circuit, with signal generator, producing the signal that a power level is x1 dBm is coupled on power circuit through electromagnetic coupled apparatus, the other end at power circuit is sent to frequency spectrograph analysis by signal by the signal receiving on electromagnetic coupler coupling device reception power line, and measuring the signal power level of now receiving is x2 dBm.Can calculate thus A (t)=x2 dBm/x1 dBm.Because experiment exists certain error, through experiment statistics repeatedly repeatedly, get mean value that its experiment gained the arrives reference value as A (t).
The method of noise N (t) parameter of introducing in power communication line transmission is obtained in statistical analysis by experiment: same in the power circuit of a topological structure, one end at power circuit couples a signal on power circuit by electromagnetic coupled apparatus with signal generator, and the other end of power circuit is sent to frequency spectrograph analysis by signal by the signal receiving on electromagnetic coupler coupling device reception power line.Because the frequency spectrum impact that the frequency spectrum of the noise N (t) introducing in power communication line transmission produces signal generator is little, remove the spectral band that signal generator is coupled to signal on power circuit, remaining spectral band is the noise N (t) of introducing.By such experiment, obtained noise N (t) parameter of introducing in the transmission of power communication circuit.
The process that in c step described in the utility model, microprocessor DSP carries out correlated characteristic extraction to baseband signal is:
The periodic feature of the digital baseband signal Wave data that analysis-reduction goes out, if exist periodically, analyze and extract the frequecy characteristic of signal, envelope characteristic, the frame length feature of signal and the frame period feature of signal of signal, these features have formed the correlated characteristic of communication baseband signal.
Wherein the periodic feature of signal waveform data is analyzed peak value and the valley of setting signal waveform in the duration by microprocessor DSP, whether the time that in statistics setting-up time, the waveform peak of signal and valley occur is particular value, whether analyze it and exist periodically, its time value is as the periodic feature of Wave data.
The frequency of signal is calculated by microprocessor DSP timer conter or Fourier analysis.Its frequency values is by differing from the frequency values recording while not adding the communication information, by signal its frequency values frequecy characteristic.
The envelope characteristic of signal by digital to analog converter by the data of storing after analog signal figure in setting-up time, analyze the numerical value of interior each crest of this period and trough, its numerical value is by differing from the parameter value recording while not adding signal of communication, by signal its parameter value envelope characteristic.
The duration of frame length when signal frame length characteristic exists communication baseband signal by the timer record in microprocessor DSP, this duration is signal frame length characteristic.
The adjacent duration continuing between two frame data when signal frame spaced features exists communication baseband signal by the timer record in microprocessor DSP equally, this duration is signal frame spaced features.
By above-mentioned technology, realize the periodic feature to signal waveform data, the frequecy characteristic of signal, envelope characteristic, signal frame length characteristic and the signal frame spaced features of signal and formed the extraction of the correlated characteristic of the baseband signal of communicating by letter.
In c step described in the utility model, microprocessor DSP judges on power communication line, whether to exist the process of communication behavior to be:
The characteristic attribute extracting and reference waveform data are carried out to sequence and subtract each other comparison calculation, the spacing parameter of the envelope to signal period property, signal, signal frame length and signal frame is added up simultaneously, whether has the basis for estimation of communication behavior as circuit.
In c step described in the utility model, signal after treatment is shown, if find to have monitored communication behavior, alarm immediately, and store useful information.
In the utility model, described broadband letter range of signal is 1MHz～80MHz, and described narrow band signal scope is 1KHz～1MHz.
Claims (6)
1. a power line information monitoring device, it is characterized in that: comprise and receive electromagnetic coupler, analog to digital converter ADC, programmable gate array FPGA, microprocessor DSP and display, described reception electromagnetic coupler sends to analog to digital converter ADC after receiving the communication information on power line, analog to digital converter ADC sends to programmable gate array FPGA after communication information A/D is changed, and on-site programmable gate array FPGA carries out the communication information receiving to send to the microprocessor DSP for judging whether to exist communication behavior after filtering and digital frequency conversion processing.
2. power line information monitoring device according to claim 1, it is characterized in that: described programmable gate array FPGA is comprised of digital filter processor and baseband processor, digital filter processor carries out the communication information receiving to send to baseband processor after filtering processing, and baseband processor carries out sending to microprocessor DSP after digital frequency conversion processing to the communication information receiving.
3. power line information monitoring device according to claim 1 and 2, is characterized in that: also comprise frequency point scanning match circuit, described frequency point scanning match circuit is receiving between electromagnetic coupler and analog to digital converter ADC.
4. power line information monitoring device according to claim 3, it is characterized in that: described reception electromagnetic coupler comprises the arrowband coupling circuit and the broadband coupling circuit that are arranged in parallel, arrowband coupling circuit is used for receiving arrowband power line carrier, PLC signal, and broadband coupling circuit is used for receiving broadband power carrier communication signal.
5. power line information monitoring device according to claim 4, is characterized in that: also comprise power supply and electric power controller, described power supply is connected to each circuit, for provide ± 15V, ± 12V, ± 9V, ± 5V, 3.3V and 1.2V power supply.
6. according to the power line information monitoring device described in claim 1,2,4 or 5, it is characterized in that: on described microprocessor DSP, be provided with 1 RS232 mouth and 1 USB mouth, RS232 mouth is for device networking monitoring, and USB mouth is for being connected intercommunication data with PC.
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| CN201320702384.2U CN203554466U (en) | 2013-11-08 | 2013-11-08 | power line information monitoring device |
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| CN201320702384.2U CN203554466U (en) | 2013-11-08 | 2013-11-08 | power line information monitoring device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107040286A (en) * | 2017-05-22 | 2017-08-11 | 珠海市晶宸科技有限公司 | A kind of enhanced power carrier signal sensor |
| CN112564736A (en) * | 2020-12-02 | 2021-03-26 | 成都立鑫新技术科技有限公司 | Dynamic blocking device and method for monitoring carrier communication of scrambling code injection type power line |
-
2013
- 2013-11-08 CN CN201320702384.2U patent/CN203554466U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107040286A (en) * | 2017-05-22 | 2017-08-11 | 珠海市晶宸科技有限公司 | A kind of enhanced power carrier signal sensor |
| CN107040286B (en) * | 2017-05-22 | 2022-11-15 | 珠海市晶宸科技有限公司 | Enhanced power carrier signal sensor |
| CN112564736A (en) * | 2020-12-02 | 2021-03-26 | 成都立鑫新技术科技有限公司 | Dynamic blocking device and method for monitoring carrier communication of scrambling code injection type power line |
| CN112564736B (en) * | 2020-12-02 | 2022-10-18 | 成都立鑫新技术科技有限公司 | Dynamic blocking device and method for monitoring carrier communication of scrambling code injection type power line |
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