CN102158601B - Internet of things telephone capable of remotely reading meter - Google Patents
Internet of things telephone capable of remotely reading meter Download PDFInfo
- Publication number
- CN102158601B CN102158601B CN201110079494.3A CN201110079494A CN102158601B CN 102158601 B CN102158601 B CN 102158601B CN 201110079494 A CN201110079494 A CN 201110079494A CN 102158601 B CN102158601 B CN 102158601B
- Authority
- CN
- China
- Prior art keywords
- module
- wireless communication
- telephone
- internet
- phone
- 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.)
- Active
Links
Images
Landscapes
- Arrangements For Transmission Of Measured Signals (AREA)
- Telephonic Communication Services (AREA)
Abstract
The invention provides an Internet of things telephone capable of remotely reading a meter, which belongs to the technical field of telecom. A wireless communication module and a voice module are arranged, a telephone line is utilized as a signal transmission antenna, data on a household electricity meter, a household gas meter and a household water meter can be automatically read in a household based on the conventional telephone by utilizing a short-range wireless communication technology, the read data is transmitted to a centralized controller module in the Internet of things telephone for processing, and information is fed back to an active querier in form of a voice information by a conventional public telephone network. The Internet of things telephone combines the short-range wireless communication module and a conventional household telephone to realize remote meter reading and remote control. Due to the extremely high popularizing rate of the telephone, the short-range wireless communication technology is flexible and convenient to distribute in the household.
Description
Technical field
The present invention relates to a kind of Internet of Things phone that can be used for remote meter reading, affiliated telecommunication technology field.
Background technology
The high speed development of computer technology, communication and microelectric technique, promoted the extensive use of Internet technology, radio-frequency (RF) tag (RFID) technology, global positioning system (GPS) and digital earth technology, and the fast development of wireless network and wireless sensor network (WSN) research, the tremendous economic that internet, applications produces and social benefit have been deepened the understanding of people to the informationalized effect.But also must input and manage by the people about the collection of human society, culture, science and technology and economic information on the Internet now.Demand for the adapt to economic development globalization, if if people imagine from the angle of information flow, RFID technology, WSN technology, GPS technology, digital earth technology and the Internet are combined, just can expand the coverage of the Internet to " thing " from " people ", just can and obtain the information of relevant logistics by RFID technology, WSN technology and the collection of GPS technology, by the Internet realize to worldwide logistics information fast, accurately identification and all-the-way tracking, this technology is exactly technology of Internet of things.
In the long distance wireless automatic electric kilowatt meter reading-out system that China has mainly used, be divided into following several by the difference of bottom communication mode:
1) mode by power carrier communication realizes that the long-range electricity this communication modes of checking meter does not need investment to lay communication line, the input of can economizing on the use of funds, also have the little characteristics of maintenance, especially in recent years the successful Application of spread spectrum technic, make the low-voltage power carrier communication begin to be applied in long distance wireless automatic electric kilowatt meter reading-out system, but power carrier communication has obvious deficiency at present: main manifestations is strong noise, Low ESR, loss is large, fluctuation is large, be subject to external interference.Some low-voltage networks in China, load variations is large and lack regularity, and various interference are very serious, and the broadband communication technology is applied to the automatic electric kilowatt meter reading-out system, the effect that does not also obtain in China at present.
2) realize that by RS485 wire communication net the long-range electricity EIA RS485 that checks meter is V.11/X.27 compatible balanced type electrical characteristic standard of standardization CCITT, RS485 wire communication Netcom crosses on the interconnecting cable of a pair of balance and to transmit differential signal and to realize transfer of data in the mode that receiving terminal carries out signal decision, it is strong that this network has an antijamming capability, long transmission distance (1200M), the characteristics of data rate high (100kb/s), but because it is cable network, need the special transmission equipment of laying, this needs extra investment cost, it uses twisted-pair feeder as network-bus in addition, support at most 128 nodes, can not satisfy the more user's of some network nodes needs, it is mainly used in a small amount of high-grade biotope in China.
3) realize that by the GPRS radio communication network the long-range electricity GPRS that checks meter is that the English of GPRS is called for short, GPRS remote auto electricity kilowatt meter reading-out system is to utilize the GPRS public network to realize the transmission of ammeter data, it uses the Internet resources of GPRS as the user of GPRS, GPRS is as the transmission network of a maturation, it is large that it has transfer rate, frequency efficiency is high, and transfer of data has the characteristics of Reliability Assurance, can satisfy the needs of remote auto electricity kilowatt meter reading-out system.But because the GPRS terminal that is arranged on each ammeter is expensive, domestic price is between 600-1500 unit, the GPRS power consumption of terminal is also larger, and from GPRS wireless remote automatic electric kilowatt meter reading-out system comes into operation, the ammeter user just needs to press data traffic to the certain expense of GPRS operator's payment always, and comprehensively its installation, maintenance and use cost, surpassed manual metering to a certain extent on the contrary, therefore, can not be widely used.At present, to fail wide popularization and application be the communication scheme of its system bottom to the Main Bottleneck in power supply enterprise's counting cost by gas meter to remote auto electricity kilowatt meter reading-out system---namely the data of each ammeter are sent to this process of processing terminal.
At present, the popularity rate of home telephone has reached quite high stage.Utilize existing public phone network to carry out Long-distance Control or remote meter reading is an economy, effectively means.Traditional phone is mainly used in interpersonal communication, perhaps black phone is carried out the existing public telephone network of part renovation and utilization, carries out simple Long-distance Control.
Now, the develop rapidly of short-distance wireless communication technology is at Smart Home, and huge contribution has been made in the aspects such as remote monitoring.In short-distance wireless communication technology, ZigBee technology has absolute advantage.The Zigbee transmission range is tens of rice, and using frequency range is free 2.4GHz and 900MHz frequency range, and transmission rate is 20kbps to 250kbps.BobHeile thinks, with respect to existing various wireless communication technologys, the low-power consumption of ZigBee technology, low rate are best suited for the standard as sensor network, and this will become the main developing direction of following ZigBee technology.In addition, the characteristics such as the Zigbee cost is low, simple in structure, power consumption is little, many advantages such as making and utilize that the network that ZigBee technology forms possesses power saving, reliable, cost is low, capacity is large, safety, self-healing property are strong, based on the mesh network structure of ZigBee technology in networking and when selecting network path more flexibly, free.ZigBee is a kind of low-power consumption based on IEEE802.15.4, low transmission rate, the simple short-distance wireless communication technology of framework, and it is at automation field, and the application in Smart Home field just more and more causes attracting attention of industry.
Summary of the invention
Technical problem
Technical problem to be solved by this invention is to provide a kind of Internet of Things phone that can be used for remote meter reading, can realize the functions such as remote inquiry, control, the data of energy Obtaining Accurate domestic consumer water, electricity, gas three tables.
Technical scheme
The present invention adopts following technical scheme for solving the problems of the technologies described above:
A kind of Internet of Things phone that can be used for remote meter reading, comprise home telephone, be attempted by the Centralized Controller on phone, described Centralized Controller comprises wireless communication module, voice module, ring detecting circuit, DTMF decoder module, auto-pickup circuit, microprocessor module;
Wherein: microprocessor module is connected with wireless communication module, voice module, ring detecting circuit, DTMF decoder module, auto-pickup circuit respectively;
Described wireless communication module and household electric, gas, water three table nodes carry out data communication.
Further, can be used for the Internet of Things phone of remote meter reading, described wireless communication module utilizes telephone wire to be used as reception antenna, can increase receiving sensitivity, increases transmission range, reduces transmitting power.
Further, can be used for the Internet of Things phone of remote meter reading, described wireless communication module adopts the CC2420 chip of supporting with Zigbee protocol.
Further, can be used for the Internet of Things phone of remote meter reading, described DTMF decoder module adopts the MT8870 chip, and the STD signal output part of described MT8870 chip connects the INT0 pin of microprocessor module.The DTMF signal that remote subscriber sends, after the stopping direct current effect of electric capacity, its relevant pin receives the dual-tone multifrequency pulse signal from telephone set, and this touch-tone signal is exported corresponding 8421 yards through computing at its data output end; The STD output signal of described MT8870 connects the INT0 pin of microprocessor module, after MT8870 obtains effective touch-tone signal, the STD level is uprised by low, after CPU detects, the indication single-chip microcomputer receives effective binary code, and invalid double-audio signal to be the STD end that can not cause MT8870 change.
A kind of method of work that can be used for the Internet of Things phone of remote meter reading comprises the steps,
Step 1, when ring detecting circuit has detected the signal incoming call, send a signal to microprocessor module, microprocessor module receives the signal that ring detecting circuit sends, call the auto-pickup circuit, the process of simulation plain old telephone off-hook connects with call initiator, call simultaneously the voice messaging of having preserved in voice module, send voice suggestion to call initiator;
Step 3 adopts microprocessor module to activate wireless communication module, and the wireless communication module with family expenses three tables by wireless communication module communicates, and completes corresponding data acquisition;
Step 4, wireless communication module feeds back to microprocessor with the data that collect by data-interface, microprocessor module is according to the data that obtain from wireless communication module, call voice module the data that collect are fed back to call initiator with the form of voice by public phone network, until the call initiator task requests all finishes;
Described wireless communication module and household electric, gas, water three table nodes can carry out normal data communication, the voice messaging that records is left in speech chip, provide the auto-pickup function, when call is arranged, the caller can complete inquiry under voice suggestion, control function.
Beneficial effect
The present invention utilizes existing public phone network that long-distance meter-reading system is installed to every household, need not set up in addition communication line, realize remote inquiry, the functions such as control, come the transmission of data larger than the reliability of electric force carrier transmission data by public telephone network, real-time data collection, the data of the water, electricity, gas table that administrative staff can the Obtaining Accurate domestic consumer; And the present invention transforms existing home phone number, and development cost is low, can reduce investment cost, and feasibility is very high.
Description of drawings
Fig. 1 is structured flowchart of the present invention;
Fig. 2 is dtmf signal decoder module figure of the present invention;
Fig. 3 is method of work schematic diagram of the present invention.
Embodiment
Embodiment of the present invention one: utilize in family existing phone to transform, on original telephone line and connect a Centralized Controller, make improved phone become core component in long-distance meter-reading system.As shown in Figure 1, Centralized Controller mainly comprises wireless communication module, voice module, ring detecting circuit, DTMF decoder module, auto-pickup circuit, microprocessor module, and microprocessor module is connected with wireless communication module, voice module, ring detecting circuit, dual tone multi-frequency dtmf decoder module, auto-pickup circuit respectively.
When phone ringing, produce the voltage signal that exchanges 48 V on its circuit, utilize electric capacity to block direct current, only allow bell signal (about 30 Hz) pass through, this moment, the photoelectrical coupler conducting made the current potential step-down of the relevant pin of single-chip microcomputer, thereby made single-chip microcomputer bell signal be detected.After processor detected 4 rings, the CPU control relay was closed, made the resistance of access 200 Ω on telephone wire by peripheral circuit, thereby switch is thought phone off-hook.
After phone incoming call and remote telephone controller off-hook were arranged, operating personnel just can be under the prompting of voice warning circuit, to water, and electricity, the gas meter data are inquired about.Sound circuit adopts voice recording and playback ic ISD4002, operational order is sent into by serial communication interface, and chip adopts many level Directly multilevel storage technology, and each sampled value directly is stored in the interior flash memory of sheet, therefore can be very true, reproducing speech, music, tone and effect sound naturally.After the voice messaging of needs promptings is entered into chip by section, under the control of CPU, the information of typing is exported by audio output, then be transported on telephone line after audio-frequency power amplifier LM386 amplifies.
Electric capacity of series connection in the middle of telephone wire and receiver.This Capacitor apart the voltage of telephone wire comprise ring, can not damage receiver like this.High pass filter can be used for the following signal of filtering short frequency.Can resist like this interference from local medium wave radio station, and the audio frequency on telephone wire is presented a kind of high impedance, the unlikely balance that affects telephone wire.Low pass filter can be used for the above signal of filtering short frequency.Can resist like this interference from FM radio station and TV signal, use simultaneously two kinds of filters, the output of one of them can be connected in the input of second filter.
The radio communication of setting up between the ZigBee adapter of family's Internet of Things telephony hardware platform and terminal equipment is connected, and is based on wirelessly to substitute wired and wireless channel that set up connects, and it does not connected in seriesly have much difference with actual.Like this, utilize the previous ZigBee kit of transplanting, after completing on the home gateway hardware platform pairing between wireless adapter and terminal equipment and being connected, just can the connected in series of this wireless channel be operated in the mode of operating equipment file, realize communication and control to terminal equipment in this locality.The content that mainly comprises two aspects: the control command that to be administrative staff send by the Internet of Things phone will send to terminal equipment by the ZigBee module, and another status data that is terminal equipment feeds back to family's Internet of Things phone also will send to by the mode of ZigBee the Internet of Things phone.In the design, wireless communication module adopts the CC2420 chip of supporting with Zigbee protocol.CC2420 is the low cost of a compatible 2.4 GHz IEEE802.15.4 standards released of Chipcon company, the active radio frequency chip of low-power consumption.It has realized physical layer (PHY) and the intermediate accesses key-course (MAC) of ZigBee agreement.This chip adopts 0.18 μ m CMOS technique, and the monolithic integrated level is high, and volume is little, and overall dimension only has 7 m * 7 m.The inner 1.8 V operating voltages of using, low in energy consumption, outside 3.3 V that use, on sheet, integrated direct current stabilizer, can become 1.8 V to the voltage transitions of 3.3 V, is suitable for battery powered equipment.In addition, CC2420 has fully-integrated voltage controlled oscillator, only needs the considerably less peripheral circuits such as antenna, 16 MHz crystal just can work on the 2.4GHz frequency range.The interface of CC2420 and microprocessor is by register mode area and the memory block of SPI interface (SI, SO, SCLK and CSn) access CC2420 inside, and high workload speed can reach 10 MHz.
Embodiment of the present invention two, from existing dual-tone multifrequency phone condensed design a ZigBee of having function can realize auto-pickup, and provide the Internet of Things phone of simplifying function of respective service for the active speaker by voice suggestion.
As shown in Figure 2, the dtmf signal decoding circuit is born by MT8870.The DTMF signal that remote subscriber sends, after the stopping direct current effect of electric capacity, its relevant pin receives the dual-tone multifrequency pulse signal from telephone set, and this touch-tone signal is exported corresponding 8421 yards through computing at its data output end.In order to make single-chip microcomputer obtain valid data, the STD output signal of MT8870 connects CPU's/the INT0 pin, after MT8870 obtains effective touch-tone signal, the STD level is uprised by low, after CPU detects, the indication single-chip microcomputer receives effective binary code, and invalid double-audio signal (telephone line noise, people's voice signal etc.) to be the STD end that can not cause MT8870 change.Wherein, the electric capacity that is connected on the power supply place has jamproof effect.
Ring detecting circuit is take optocoupler 817 as main formation, when bell signal is arranged, ringing-current enters 817 input pins and output pulse square wave signal, deliver to single-chip microcomputer external interrupt pin, far below ringing signal voltage, this circuit can not cause erroneous judgement due to voice signal and double-audio signal voltage.
Though this Internet of Things phone can not initiatively make a call, can realize the needed actual functional capability of remote meter reading.
above-mentioned is the hardware designs of this Internet of Things phone, the concrete method of work of the present invention is as follows: as Fig. 1, shown in 3, step 1, under normal state, this Internet of Things phone is in holding state, when ring detecting circuit has detected the signal incoming call, send a signal to processor, processor receives the signal that ring detecting circuit sends, Automatically invoked is answered circuit, the process of simulation plain old telephone off-hook, connect with active call side, call simultaneously the voice messaging of having preserved in voice module, select suitable voice signal to feed back to call initiator by telephone wire, send voice suggestion to call initiator, step 2, when active call person receives voice suggestion, select corresponding button, when microprocessor module receives the key information of calling party transmission, call the DTMF decoder module, after by the DTMF decoder module, the push button signalling that receives being decoded, the key assignments that decoding is obtained feeds back to microprocessor module, microprocessor module goes to carry out corresponding action and completes caller's task requests according to the key assignments that obtains, step 3, when the caller need to gather the data that family expenses three are shown, microprocessor module activates wireless communication module, send corresponding instruction by the interface with wireless communication module, connect by the wireless communication module on the wireless communication module on phone and table, complete corresponding data acquisition, step 4, wireless communication module feeds back to processor with the data that collect by data-interface, microprocessor is according to the data that obtain from wireless communication module, after the suitable voice messaging of having stored that calls simultaneously voice module is processed, the data that collect are fed back to active call person with the form of voice by public phone network, until the call initiator task requests all finishes, and initiatively on-hook of calling party detected, processor reactivates ring detecting circuit, and other modules are set to holding state, wait call request next time.
Claims (3)
1. Internet of Things phone that can be used for remote meter reading, it is characterized in that: comprise home telephone, be attempted by the Centralized Controller on phone, described Centralized Controller comprises wireless communication module, voice module, ring detecting circuit, DTMF decoder module, auto-pickup circuit, microprocessor module; Wherein: microprocessor module is connected with wireless communication module, voice module, ring detecting circuit, DTMF decoder module, auto-pickup circuit respectively; Described wireless communication module and household electric, gas, water three table nodes carry out data communication;
Described wireless communication module utilizes telephone wire to be used as reception antenna, electric capacity of series connection, one are used for the high pass filter of the following signal of filtering short frequency in the middle of telephone wire and receiver, and a low pass filter that is used for the above signal of filtering short frequency, the output of one of them filter is connected in the input of another filter; When phone ringing, produce the voltage signal that exchanges 48 V on its circuit, utilize electric capacity to block direct current, only allow 30 Hz bell signals pass through, this moment, the photoelectrical coupler conducting made the current potential step-down of the relevant pin of microprocessor module, thereby made microprocessor module bell signal be detected; After microprocessor module detected 4 rings, the CPU control relay was closed, made the resistance of access 200 Ω on telephone wire by peripheral circuit, thereby switch is thought phone off-hook; Specifically comprise the steps during the Internet of Things phone works,
Step 1, when ring detecting circuit has detected the signal incoming call, send a signal to microprocessor module, microprocessor module receives the signal that ring detecting circuit sends, call the auto-pickup circuit, the process of simulation plain old telephone off-hook connects with call initiator, call simultaneously the voice messaging of having preserved in voice module, send voice suggestion to call initiator;
Step 2, call initiator sends request of data by telephone key-press to microprocessor module, when microprocessor module receives the request of data of calling party transmission, call the DTMF decoder module, after by the DTMF decoder module, the push button signalling that receives being decoded, the key assignments that decoding is obtained feeds back to microprocessor module;
Step 3 adopts microprocessor module to activate wireless communication module, and the wireless communication module with family expenses three tables by wireless communication module communicates, and completes corresponding data acquisition;
Step 4, wireless communication module feeds back to microprocessor with the data that collect by data-interface, microprocessor module is according to the data that obtain from wireless communication module, call voice module the data that collect are fed back to call initiator with the form of voice by public phone network, until the call initiator task requests all finishes;
Step 5, microprocessor module reactivates ring detecting circuit, and other modules are set to holding state, wait call request next time.
2. a kind of Internet of Things phone that can be used for remote meter reading according to claim 1, it is characterized in that: described wireless communication module adopts the CC2420 chip of supporting with Zigbee protocol.
3. a kind of Internet of Things phone that can be used for remote meter reading according to claim 1, it is characterized in that: described DTMF decoder module adopts the MT8870 chip, and the STD signal output part of described MT8870 chip connects the INT0 pin of microprocessor module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110079494.3A CN102158601B (en) | 2011-03-31 | 2011-03-31 | Internet of things telephone capable of remotely reading meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110079494.3A CN102158601B (en) | 2011-03-31 | 2011-03-31 | Internet of things telephone capable of remotely reading meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102158601A CN102158601A (en) | 2011-08-17 |
| CN102158601B true CN102158601B (en) | 2013-11-06 |
Family
ID=44439771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110079494.3A Active CN102158601B (en) | 2011-03-31 | 2011-03-31 | Internet of things telephone capable of remotely reading meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102158601B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104284038A (en) * | 2013-07-05 | 2015-01-14 | 施耐德电器工业公司 | Service electricity meter calling system and service electricity meter calling method |
| TWI682677B (en) * | 2017-11-08 | 2020-01-11 | 中華電信股份有限公司 | System and method for monitoring iot devices based on ringback tone service |
| CN110177454A (en) * | 2017-11-30 | 2019-08-27 | 南京德朔实业有限公司 | Electric tool system and upgrade method for the system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1319982A (en) * | 2001-04-12 | 2001-10-31 | 刘向华 | Intelligent domestic electric appliance control system and realizing method |
| CN1414346A (en) * | 2002-05-20 | 2003-04-30 | 孙龙喜 | Method of remote meter data recording and remote meter data recording system |
| CN201204616Y (en) * | 2008-01-03 | 2009-03-04 | 刘望舒 | Using telephone voice channel as module of data facsimile communication |
| CN201515424U (en) * | 2009-05-26 | 2010-06-23 | 陈贵 | Embedded phone system playing voice according to keystroke |
-
2011
- 2011-03-31 CN CN201110079494.3A patent/CN102158601B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1319982A (en) * | 2001-04-12 | 2001-10-31 | 刘向华 | Intelligent domestic electric appliance control system and realizing method |
| CN1414346A (en) * | 2002-05-20 | 2003-04-30 | 孙龙喜 | Method of remote meter data recording and remote meter data recording system |
| CN201204616Y (en) * | 2008-01-03 | 2009-03-04 | 刘望舒 | Using telephone voice channel as module of data facsimile communication |
| CN201515424U (en) * | 2009-05-26 | 2010-06-23 | 陈贵 | Embedded phone system playing voice according to keystroke |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102158601A (en) | 2011-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201674496U (en) | Power line carrier and wireless communication conversion device and power line carrier meter reading system | |
| CN102117537A (en) | Meter reading gateway, meter reading system and meter reading method | |
| CN204596133U (en) | A kind of gas meter, flow meter meter reading management system based on intelligent terminal | |
| CN104318736A (en) | 3G network-based remote intelligent meter reading system with four meters in one | |
| CN110176948A (en) | LoRa+PLC bimodulus built-in module and the communication structure and the means of communication for using the module | |
| CN102158601B (en) | Internet of things telephone capable of remotely reading meter | |
| CN104318748A (en) | A remote intelligent meter reading system integrating four meters | |
| CN209659304U (en) | LoRa+PLC bimodulus built-in module and the communication structure for using the module | |
| CN100594686C (en) | Method and apparatus for realizing remote wireless monitoring via wireless network | |
| CN107124691A (en) | A kind of WiFi intelligent cut-in methods of low-power consumption bluetooth auxiliary | |
| CN207852074U (en) | A kind of automatic data logging harvester | |
| CN109920232A (en) | Electric power multi service access terminal and management system based on NB-loT | |
| CN203130462U (en) | Remote inquiring and control system of photovoltaic water pump | |
| JP6021602B2 (en) | Centralized management system for measurement information | |
| CN201654999U (en) | Remote concentrated meter reading system for fuel gas | |
| CN201114296Y (en) | GPS positioning communications interphone | |
| CN201294641Y (en) | Remote monitoring gateway based on ZigBee technology | |
| CN104240476A (en) | Method and system for realizing telecommunication of TG-Inwicos based II type collector | |
| CN201887846U (en) | Communication system utilizing ready-made telephone line | |
| CN105513308A (en) | Wireless meter reading system | |
| CN102223458A (en) | Communication system using ready-made telephone line | |
| CN203434973U (en) | Carrier-wave wireless converter | |
| CN207910944U (en) | A kind of radio voice pinboard | |
| CN201063618Y (en) | Power line modem | |
| CN201749555U (en) | Remote meter-reading device of electrodynamometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |