CN201289499Y - Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof - Google Patents
Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof Download PDFInfo
- Publication number
- CN201289499Y CN201289499Y CNU2008201546766U CN200820154676U CN201289499Y CN 201289499 Y CN201289499 Y CN 201289499Y CN U2008201546766 U CNU2008201546766 U CN U2008201546766U CN 200820154676 U CN200820154676 U CN 200820154676U CN 201289499 Y CN201289499 Y CN 201289499Y
- Authority
- CN
- China
- Prior art keywords
- sampling
- unit
- parameter
- bus driver
- carrier wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Arrangements For Transmission Of Measured Signals (AREA)
Abstract
The utility model relates to a low-voltage carrier wave concentrator terminal and an alternating current sampling unit thereof. The alternating current sampling unit is used for adding the alternating current sampling function for the low voltage carrier wave concentrator terminal, and comprises a mutual inductor, an alternating current sampling chip, a bus driver, a microcontroller and a memory. The mutual inductor acquires a small alternating current signal from a strong alternating current signal, and the alternating current sampling chip samples the parameters of the small alternating current signal and outputs such sampling data as voltage, current and power. The microcontroller acquires the parameters of the small alternating current signal and sends the parameters to the external bus via the bus driver. The memory is used for storing the parameters of the small alternating current signal.
Description
Technical field
The utility model relates to low pressure carrier wave concentrator terminal, relates in particular to a kind of low pressure carrier wave concentrator terminal and AC sampling unit thereof that has the AC sampling function.
Background technology
Low pressure carrier wave concentrator terminal (hereinafter to be referred as terminal) is an of paramount importance ingredient in resident's centralized and automatic kilowatt meter reading-out system (hereinafter to be referred as centralized meter-reading system), and concentrator is the equipment of a distribution zone acquiring electric energy information and control.It is gathered, handles, stores and control the collector of its administration and the information of all kinds of electric energy meters by channel, and by telepak and main website swap data.Its main effect is data acquisition and the storage that realizes all meter reading terminals of residential area in centralized meter-reading system, realizes the communication of main website with concentrator and each meter reading terminal.
Fig. 1 is the theory diagram of the existing low pressure carrier wave concentrator terminal of using always.With reference to shown in Figure 1, existing concentrator terminal 100 mainly is made up of main control unit 110, descending RS485 unit 120, carrier communication unit 130, uplink communication unit 140, power supply unit 150 etc.
Descending RS485 unit (being the RS485 interface) 120 is drawn by the serial port in the main control unit 110, and interface all adopts optocoupler and main control MCU partly to isolate.The effect of this unit is the real-time electric weight or the power information of gathering concentrator periphery table meter terminal by 485 data lines.
Existing concentrator terminal commonly used has played the effect of " forming a connecting link " in whole resident's centralized meter-reading system, can by down going channel (carrier channel and 485 channels) gather resident's electric energy meter data, regularly the real-time electric weight of the other table meter terminal of copy reading platform district transformer or power information, preservation subscriber's meter meter freeze electric quantity data, can give the main website of system in order to analysis with add up by the data upload that data feedback channel will be gathered and preserve again.
Fig. 2 is the existing wiring schematic diagram of low pressure carrier wave concentrator in centralized meter-reading system.As shown in Figure 2, near platform district transformer 200, it calls real-time electric weight or the power information of survey, each table meter 201-20N of timing copy reading together in real time by carrier channel substantially in the position that concentrator terminal 100 is installed, and can preserve the electric quantity data that freezes of subscriber's meter meter; Main website of system 1000 recalls by the data that the GPRS/CDMA channel is gathered concentrator 100 and preserve again.Table meter terminal 210 on the concentrator terminal 100 He Tai district transformers connects by 485 data lines, information such as real-time electric weight of sampling up in order to acquisition tables meter terminal and electricity consumption data.
The function of above-mentioned existing concentrator is comparatively single, only has collection, storage, basic function such as upload, if the function that can on the basis of these functions, increase exchanges and sample with smaller cost, a tractor serves several purposes is accomplished in the effect of substitution tables meter terminal to a certain extent of that such terminal, thereby accomplishes to reduce the purpose of management of power use cost.
The utility model content
Technical problem to be solved in the utility model provides a kind of low pressure carrier wave concentrator terminal that has the AC sampling function, can meet the needs of modern management of power use mode more so that the function of concentrator terminal is diversified more.
The utility model is to solve the problems of the technologies described above the AC sampling unit that the technical scheme that adopts is a kind of low pressure carrier wave concentrator terminal of proposition, comprises mutual inductor, AC sampling chip, bus driver, microcontroller and storer.Mutual inductor is taken a sample from the forceful electric power AC signal and is obtained ac small signal.The AC sampling chip connects mutual inductor, and the parameter of sampling ac small signal is also exported these parameters, and wherein these parameters comprise voltage, electric current and power.Bus driver is in order to the external bus communication by this AC sampling unit of connection.Microcontroller connects AC sampling chip and bus driver, and it obtains the parameter of ac small signal and outwards sends through bus driver.Storer connects microcontroller, preserves the parameter of ac small signal.
In an embodiment of the present utility model, above-mentioned AC sampling chip comprises three single-phase electric energy meter special chips, and wherein each single-phase electric energy meter special chip is in order to the parameter of the cross streams signal in the sampling three-phase electricity.
In an embodiment of the present utility model, above-mentioned AC sampling unit also comprises the cycle sample circuit, the waveform of electric current and voltage is sampled obtaining the phase differential between the synchronous voltage and current, and send above-mentioned phase differential to above-mentioned microcontroller.
In an embodiment of the present utility model, above-mentioned bus driver is the CAN bus driver.
The utility model also provides a kind of low pressure carrier wave concentrator terminal, comprises an above-mentioned AC sampling unit and a main control unit.Main control unit comprises bus driver and host microcontroller.Bus driver is in order to by external bus and AC sampling unit communication.Host microcontroller connects this bus driver, obtains the parameter of ac small signal through bus driver thus.
In an embodiment of the present utility model, above-mentioned low pressure carrier wave concentrator terminal also comprises the uplink communication unit that connects described main control unit.
In an embodiment of the present utility model, above-mentioned low pressure carrier wave concentrator terminal also comprises the carrier communication unit that connects described main control unit.
In an embodiment of the present utility model, above-mentioned low pressure carrier wave concentrator terminal also comprises the descending RS485 unit that connects described main control unit.
In an embodiment of the present utility model, above-mentioned AC sampling unit is can be with respect to the module of described low pressure carrier wave concentrator terminal plug.
Because the utility model has adopted above technical scheme, on the basis of existing low pressure carrier wave concentrator, increased the AC sampling function, make that terminal can the effect of replacement table meter terminal in this kilowatt meter reading-out system in resident's automatic meter reading system, also make terminal variation more on function.
Description of drawings
For above-mentioned purpose of the present utility model, feature and advantage can be become apparent, below in conjunction with accompanying drawing embodiment of the present utility model is elaborated, wherein:
Fig. 1 is the theory diagram of the existing low pressure carrier wave concentrator terminal of using always.
Fig. 2 is the existing wiring schematic diagram of low pressure carrier wave concentrator in resident's centralized meter-reading system.
Fig. 3 is the low pressure carrier wave concentrator terminal structure block diagram of the utility model one embodiment.
Fig. 4 is the wiring schematic diagram of low pressure carrier wave concentrator of the present utility model in resident's centralized meter-reading system.
Embodiment
With reference to shown in Figure 3, the low pressure carrier wave concentrator terminal 300 of the utility model one embodiment adopts modular design, comprising: main control unit 310, AC sampling unit 320, uplink communication unit 330, carrier communication unit 340, descending RS485 unit 350 and power unit.
Continue with reference to shown in Figure 3, in the present embodiment, main control unit 310 is a core with main MCU (LPC2292) 311, program storage (SST39VF1601) 312 of its outside expansion 1M x 16bit, total volume are that NAND (with non-) flash memory (K9F5608) 314 of SRAM (BS62LV1600 * 2) 313 of 4MB and a slice 32MB is as data-carrier store.So just made up the minimum system of be in order an operation and a data storage.
The real-time clock 315 of main control unit 310 adopts the RX8025 of EPSON company, and it has the IIC interface, and interior band crystal oscillator (frequency stability is 5ppm during normal temperature) also can software position precision.Main control unit 310 also has supply voltage monitoring circuit 316, and multiple interrupt mode and pulse output function are arranged.Reserve large capacity one-time lithium battery 317, clock switches to the lithium battery power supply state after the power down.
Because main MCU 311 has only two standard UART mouths, in order to satisfy the demand of terminal to serial port, its outside expansion a slice 4 serial port chip (SC16C554) 318, this serial port chip 318 is connected with parallel interface with 311 of main MCU, the UART mouth that serial port chip 318 built-in 4 passage baud rates can independently be provided with, every passage all have the transmitting-receiving FIFO (First-In First-Out) of 16 bytes to be used for data buffering.Wherein two serial ports of serial port chip 318 are as the RS485 interface, and other has a serial ports to be used for local infrared mouthful, also has a serial ports to keep.
For improving the speed of data access, main control unit 310 provides jumbo SRAM 313, the data of gathering leave among the SRAM 313 at ordinary times, the data that will cut off the power supply when timing or outage needs to preserve write preservation in the nand flash memory 314, in order to guarantee when cutting off the power supply, have time enough data to be write in the nand flash memory 314, main control unit has also comprised supply voltage monitoring circuit 316, when power down, in time monitor power-down conditions, reserve time enough by the super capacitor on the plate and write the data that outage need be preserved for main MCU 311.
Continue with reference to shown in Figure 3, AC sampling unit 320 comprises auxilliary MCU (LPC2119) 321, mutual inductor 322 and AC sampling chip (CS5460A) 323.The alternating voltage of forceful electric power input and electric current are by mutual inductor 322, be varied to AC sampling chip 323 acceptable small-signals, take a sample by sample resistance, become the alternating voltage of about 100mV, this signal enters the signal conditioning circuit of AC sampling chip 323 peripheries, realization is to the filtering of high-frequency signal, and the input AC sampling A 323 again.323 pairs of data such as voltage, electric current and power of AC sampling chip are sampled, by with the interface circuit of auxilliary CPU 321, send among the auxilliary CPU 321 with digital form.
Auxilliary MCU 321 is core components of AC sampling unit 320, and it is 32 ARM7 microprocessors, and built-in 128K program storage and WatchDog Timer can be realized the ISP function, the download of application program.The outside expansion of auxilliary MCU ferroelectric memory 324 is preserved sampled data.Auxilliary MCU 321 communicates by letter with second bus driver 319 of main control unit 310 by a CAN bus driver 325, sends the data of AC sampling to main MCU 311 through second bus driver 319.
CS5460A inside does not contain the output of reactive power, but can be by applied power and active power, indirect calculation goes out reactive power, and the symbol of reactive power can be by the sampled result to the electric current and voltage instantaneous value, obtain the phase relation of electric current and voltage, further determine the symbol of reactive power.Because CS5460A can gather voltage, current instantaneous value, the reactive power data also can adopt samples then to instantaneous value that the method for integral and calculating obtains in addition.Because CS5460A has sampling function to the electric current and voltage instantaneous value, thereby can carry out the calculating of harmonic component, obtain the harmonious ripple amount of humorous wave amplitude, in theory, its higher harmonics is measured number of times and can be reached more than 19 times.
Because CS5460A is single-phase chip, so need multi-plate chip to form three-phase system.Specifically, need three CS5460A under the three-phase four-wire system, need two CS5460A under the three-phase three-wire system.CS5460A has the software calibration function, can under the situation that need not external adjustment circuit, adjust zero point and full scale, and can these adjusted values be saved in the storer as parameter by software, improved reliability on the one hand, can enhance productivity on the other hand.
In addition, cycle sample circuit 326 also is set in the AC sampling unit 320, it mainly acts on samples to judge whether phase differential is arranged between the synchronous voltage and current to the waveform of electric current and voltage, and send this difference to auxilliary MCU 321, make its electric current and voltage instantaneous value that can Integrated Exchange sampling A 323 sends calculate reactive power, and can calculate phasing degree and power factor in view of the above.
Get back to shown in Figure 3ly, uplink communication unit 330 is exactly the remote channel between concentrator terminal 300 and the main website 2000 (referring to Fig. 4).At present, uploading channel mainly adopts the GPRS/CDMA mode.In the present embodiment, adopt the GR64 unit of SONY ERICSSON.Its built-in ICP/IP protocol is supported the JAVA utilization.Because its control and data transmission are controlled by CPU, control mode is flexible, adopts other unit if change, and the change of software and hardware is all little.
Two RS485 interface RS485_1, RS485_2 of descending RS485 unit 350 are drawn by the extended serial mouth 318 of main control unit; two interfaces all adopt optocoupler 353 and main control MCU partly to isolate; this partial design is for having anti-lightning strike surge protection ability, and considers the holding circuit after the AC power cord misconnection.
Power unit mainly carries out necessary voltage transitions.Power supply becomes three groups of direct supplys of isolating with AC voltage conversion, and one group of 5VDC gives host CPU and auxilliary the use; One group of 5VDC gives the RS485 interface; Another group 12VDC give the power supply of carrier communication plate.In addition, in order to satisfy the needs of tributary analog acquisition and remote control/remote signalling circuit, also consider to adopt DC/DC to change out each one group of 12V, 5V power supply to power supply.Terminal adopts three phase supply, and phase three-wire three disconnected any can be worked mutually; The disconnected any two-phase of three-phase and four-line can be worked.Inlet wire part and the carrier channel of considering power supply are shared, and the reply interlock circuit carries out suitable adjustment and the components and parts type selecting is expounded adequately on unit design, to reduce the influence of power panel to route plate carrier communication effect itself.
Because terminal 300 has increased the AC sampling function, therefore mutual inductor 322 generally all is installed in mutual inductor on the power supply unit owing to will receive outside forceful electric power signal, to reduce the influence of strong power part to weak current part.General AC sampling adopts the mode of three-phase and four-line or phase three-wire three, according to different wiring needs, matches different mutual inductor array modes.
In addition, the one-piece construction of terminal also adopts modular design, and uplink communication unit 330, carrier communication unit 340 and AC sampling unit 320 can be dismantled, and make things convenient for function selecting and plant maintenance.
Fig. 4 is the wiring schematic diagram of low pressure carrier wave concentrator of the present utility model in resident's centralized meter-reading system.With reference to shown in Figure 4, it illustrates main website of system 2000, public internet network 500 and is distributed in terminal 300 in a plurality of zones.There are a plurality of carrier electric energy meter 401-40N the terminal region.Concentrator terminal 300 is called real-time electric weight or the power information of survey, each table meter 401-40N of timing copy reading in real time together by carrier channel.
For simplicity, concentrator terminal 300 only illustrates the part interface.Terminal 300 is built-in one tunnel AC sampling unit 320, can measure 220V (four lines)/100V (three-way) voltage and 5A electric current, and can measure this unit reactive power and electric weight arranged, the data that record can be called survey together by main website of system 2000 by uplink communication unit 330 (GPRS/CDMA), the Various types of data curve can be drawn according to the data of calling survey together by main website 2000, make comparisons with the data and curves that measuring terminal is beamed back, whether normal with the electricity consumption situation of determining these district's transformer 400 secondary side zones.By with existing system shown in Figure 2 more as can be known, present embodiment can be provided with table meter terminal again.
In sum, because the foregoing description of the present utility model has increased the AC sampling function on the basis of existing low pressure carrier wave concentrator, make that terminal can the effect of replacement table meter terminal in this kilowatt meter reading-out system in resident's automatic meter reading system, also make terminal variation more on function.
Though the utility model discloses as above with preferred embodiment; right its is not in order to limit the utility model; any those skilled in the art; in not breaking away from spirit and scope of the present utility model; when doing a little modification and perfect, therefore protection domain of the present utility model is worked as with being as the criterion that claims were defined.
Claims (9)
1. the AC sampling unit of a low pressure carrier wave concentrator terminal is characterized in that comprising:
Mutual inductor, sampling obtains ac small signal from the forceful electric power AC signal;
The AC sampling chip connects described mutual inductor, and the parameter of the described ac small signal of sampling is also exported described parameter, and wherein said parameter comprises voltage, electric current and power;
Bus driver is in order to the external bus communication by this AC sampling unit of connection;
Microcontroller connects described AC sampling chip and described bus driver, and described microcontroller obtains the parameter of described ac small signal and outwards sends through described bus driver; And
Storer connects described microcontroller, preserves the parameter of described ac small signal.
2. AC sampling as claimed in claim 1 unit is characterized in that, described AC sampling chip comprises three single-phase electric energy meter special chips, and wherein each single-phase electric energy meter special chip is in order to the parameter of the cross streams signal in the sampling three-phase electricity.
3. AC sampling as claimed in claim 1 unit is characterized in that, also comprises the cycle sample circuit, the waveform of electric current and voltage is sampled obtaining the phase differential between the synchronous voltage and current, and send described phase differential to described microcontroller.
4. AC sampling as claimed in claim 1 unit is characterized in that, described bus driver is the CAN bus driver.
5. low pressure carrier wave concentrator terminal is characterized in that comprising:
The AC sampling unit, it comprises:
Mutual inductor, sampling obtains ac small signal from the forceful electric power AC signal;
The AC sampling chip connects described mutual inductor, and the parameter of the described ac small signal of sampling is also exported described parameter, and wherein said parameter comprises voltage, electric current and power;
First bus driver is in order to the external bus communication by this AC sampling unit of connection;
Auxilliary microcontroller connects described AC sampling chip and described bus driver, and described microcontroller obtains the parameter of described ac small signal and outwards sends through described bus driver; And
Storer connects described microcontroller, preserves the parameter of described ac small signal;
Main control unit, it comprises:
Second bus driver is in order to by described external bus and described AC sampling unit communication; And
Host microcontroller connects described second bus driver, obtains the parameter of described ac small signal via described second bus driver.
6. low pressure carrier wave concentrator terminal as claimed in claim 5 is characterized in that, also comprises the uplink communication unit that connects described main control unit.
7. low pressure carrier wave concentrator terminal as claimed in claim 5 is characterized in that, also comprises the carrier communication unit that connects described main control unit.
8. low pressure carrier wave concentrator terminal as claimed in claim 5 is characterized in that, also comprises the descending RS485 unit that connects described main control unit.
9. low pressure carrier wave concentrator terminal as claimed in claim 5 is characterized in that, described AC sampling unit is can be with respect to the module of described low pressure carrier wave concentrator terminal plug.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201546766U CN201289499Y (en) | 2008-10-30 | 2008-10-30 | Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201546766U CN201289499Y (en) | 2008-10-30 | 2008-10-30 | Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201289499Y true CN201289499Y (en) | 2009-08-12 |
Family
ID=40981181
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201546766U Expired - Fee Related CN201289499Y (en) | 2008-10-30 | 2008-10-30 | Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201289499Y (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102279314A (en) * | 2010-06-12 | 2011-12-14 | 刘长利 | Noncontact electric energy information acquiring and controlling device |
| CN103312561A (en) * | 2013-05-30 | 2013-09-18 | 国家电网公司 | Detection method for intelligent concentrator |
| CN104483541A (en) * | 2014-12-01 | 2015-04-01 | 沈阳大学 | GPRS (General Packet Radio Service) electric power acquisition system |
| CN106053935A (en) * | 2016-06-08 | 2016-10-26 | 贵州电网有限责任公司电力科学研究院 | Double-MCU scheme building-block application program upgradeable intelligent ammeter |
| CN106093559A (en) * | 2016-06-08 | 2016-11-09 | 贵州电网有限责任公司电力科学研究院 | Single MCU scheme scalable intelligent electric energy meter of building block system application program |
| CN111654423A (en) * | 2020-05-06 | 2020-09-11 | 上海挚想科技有限公司 | System, method and medium for realizing data transmission based on CAN bus |
| CN113965821A (en) * | 2021-09-10 | 2022-01-21 | 江苏方天电力技术有限公司 | Digital district multi-source heterogeneous communication routing system and method |
-
2008
- 2008-10-30 CN CNU2008201546766U patent/CN201289499Y/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102279314A (en) * | 2010-06-12 | 2011-12-14 | 刘长利 | Noncontact electric energy information acquiring and controlling device |
| CN103312561A (en) * | 2013-05-30 | 2013-09-18 | 国家电网公司 | Detection method for intelligent concentrator |
| CN103312561B (en) * | 2013-05-30 | 2016-12-28 | 国家电网公司 | A kind of detection method of intelligent concentrator |
| CN104483541A (en) * | 2014-12-01 | 2015-04-01 | 沈阳大学 | GPRS (General Packet Radio Service) electric power acquisition system |
| CN106053935A (en) * | 2016-06-08 | 2016-10-26 | 贵州电网有限责任公司电力科学研究院 | Double-MCU scheme building-block application program upgradeable intelligent ammeter |
| CN106093559A (en) * | 2016-06-08 | 2016-11-09 | 贵州电网有限责任公司电力科学研究院 | Single MCU scheme scalable intelligent electric energy meter of building block system application program |
| CN111654423A (en) * | 2020-05-06 | 2020-09-11 | 上海挚想科技有限公司 | System, method and medium for realizing data transmission based on CAN bus |
| CN113965821A (en) * | 2021-09-10 | 2022-01-21 | 江苏方天电力技术有限公司 | Digital district multi-source heterogeneous communication routing system and method |
| CN113965821B (en) * | 2021-09-10 | 2024-01-26 | 江苏方天电力技术有限公司 | Digital district multi-source heterogeneous communication routing system and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201289499Y (en) | Low-voltage carrier concentrator terminal and intercommunion sampling unit thereof | |
| CN201639363U (en) | Comprehensive three-state data measuring and control device for intelligent transformer station | |
| CN104698320B (en) | The electric Parameter Measuring device and method of power transmission and distribution circuit | |
| CN104732751A (en) | Automatic meter reading system and automatic meter reading method based on RF (radio frequency) and GPRS (general packet radio service)/3G (the 3rd generation telecommunication) | |
| CN201859537U (en) | Multifunctional bandwidth power carrier concentrator | |
| CN105870974B (en) | Distributed photovoltaic grid-connected system electrical parameter bidirectional measurement device | |
| CN106406108A (en) | Intelligent household electric controller and control method | |
| CN215641543U (en) | Line monitoring terminal with characteristic signal sending and identifying functions | |
| CN109490667A (en) | A kind of distribution transformer monitoring terminal | |
| CN202434042U (en) | Automatic meter reading system | |
| CN105958647A (en) | Comprehensive measurement and regulation-control apparatus and method for active power distribution network | |
| CN201270433Y (en) | Multi-path load management terminal apparatus | |
| WO2013056606A1 (en) | Energy efficiency data concentration terminal | |
| CN200996971Y (en) | Composite electric-energy managing system of load control and multiplexing time-sharing charging | |
| CN206948036U (en) | A kind of intelligent distribute-electricity transformer district terminal | |
| CN103986231A (en) | Networked intelligent transformer substation metering system | |
| CN216312755U (en) | But remote monitoring's vary voltage cabinet | |
| CN208110832U (en) | Electric energy meter data acquisition equipment | |
| CN104333016A (en) | Dispersing type reactive compensation system for low-voltage power distribution network | |
| CN206741693U (en) | A kind of phasor data concentrator | |
| CN201749558U (en) | Acquisition terminal of low-voltage power line carrier resident electric meter | |
| CN202872459U (en) | Intelligent distribution terminal telemetry board | |
| CN202075618U (en) | Intelligent remote measurement and control terminal | |
| CN210427662U (en) | Distribution line loss acquisition module | |
| CN115173893A (en) | Full-load testing device for HPLC broadband carrier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090812 Termination date: 20171030 |