Descending M-BUS, up RF wireless collection device
(1) technical field
The utility model discloses a kind of descending M-BUS, up RF wireless collection device.
(2) background technology
Along with progress of science and technology and expanding economy, remote meter reading has been widely used in the management of water, electricity, gas, heat, and the intermediate equipment that collector is communicated by letter with the table meter as concentrator seems particularly important in long-distance meter-reading system.At present, the known collector that is applied to kilowatt meter reading-out system, still be to be to realize no matter by RS-485 bus, M-BUS bus, GPRS/GSM network and four kinds of communication patterns of wireless data transmission module with descending table meter major part with up concentrator, but all be basic application, how make the communication performance of collector more perfect, transmission rate more fast needs the technical staff to make joint efforts.
The utility model patent is descending M-BUS, up RF wireless collection device, has mainly optimized following performance: 1, adopt three Switching Power Supplies, make power supplying efficiency up to more than 90%, and compare with the product of identical function, volume is less.2, descending M-BUS, up RF is wireless employing double mcu can make up, downlink communication mutually noninterfere, and message transmission rate is fast.
(3) utility model content
The purpose of this utility model is the defective that overcomes existing collector uplink and downlink communication, and a kind of performance optimization, the descending M-BUS that cost is low, transmission rate is fast, the collector that up RF is wireless are provided.
Implementation of the present utility model is as follows:
Collector is up to adopt the RF wireless data transmission module to realize with concentrator, and descending and table meter adopts the M-BUS bus mode to communicate.
Further scheme is:
Power unit: the 220V civil power is divided into two terminals behind transformer after rectification chip (DB102S) is rectified into two-way voltage, adopt three Switching Power Supplies to give the M-BUS interface circuit respectively, inner control module and functional module power supply, the internal oscillator of the built-in 260KHZ fixed frequency of switching power source chip, when the waveform of the built-in waveform generator generation of switching power source chip is high level, built-in chip type transistor saturation conduction, input voltage gives inductance L 3 charging energy storage by built-in transistor, charging current is linear to be increased, diode D3 ends, 3 pairs of load resistance discharges of inductance L, filter capacitor C also discharges to load resistance simultaneously; When the waveform of built-in chip type waveform generator generation was low level, built-in transistor ended, and inductance L 3 produces induced electromotive forces, and by Lenz's law as can be known, the load current direction is constant.
By last, regardless of the state regardless of diode D3 in transistorized state of built-in chip type and the peripheral circuit, inductance L 3 can provide electric current to load all the time.
Further scheme is:
Described descending M-BUS communication, its hardware controls partly contains microcontroller (MEGA88V), data transmit circuit, data receiver circuit, warning circuit, memory module (AT24C256A).
Further scheme is:
Described up RF radio communication, its hardware controls partly contain microcontroller (ATMEGA88), UHF wireless transceiver (CC1100) and peripheral circuit thereof, wireless data receiving circuit, wireless data transtation mission circuit, antenna.
The beneficial effects of the utility model:
(1) the descending M-BUS of the utility model, up RF wireless collection device power unit adopt three Switching Power Supplies to give M-BUS bus, inner functional module power supply respectively, and power supplying efficiency can reach 90%, and with the product of identical function mutually specific volume reduce.
(2) the descending M-BUS of the utility model, up, the downlink communication employing double mcu of up RF wireless collection device make uplink and downlink communication mutually noninterfere, and message transmission rate is fast.。
(4) description of drawings
Accompanying drawing 1 is the descending M-BUS of the utility model, up RF wireless collection device structured flowchart
Accompanying drawing 2-1～2-12 is the descending M-BUS of the utility model, up RF wireless collection device power unit, downlink communication partial circuit figure
Accompanying drawing 3-1～3-4 is the descending M-BUS of the utility model, up RF wireless collection device uplink communication partial circuit figure
Below in conjunction with embodiment the technical solution of the utility model is described in further detail.
Power unit: the 220V civil power is divided into two terminals behind transformer after rectification chip (DB102S) is rectified into two-way voltage, adopt three switching power source chips (LM2675-ADJ), output voltage is respectively+18V ,-24V ,+5V, wherein+18V ,-24V provides positive-negative power for the M-BUS bus interface circuit; + 5V provides power supply for microcontroller and peripheral circuit thereof and RF wireless module.
Descendingly carry out M-BUS with table meter and communicate by letter:
Data transmit circuit: when collector sends data to the table meter, the TX port of microcontroller connects the base stage of triode T1 through resistance R 8, the grounded emitter of T1, collector electrode is sent into the input in the same way of operational amplifier TLE2301, the inverting input of amplifier is ground connection after resistance R 26,12V which amplitude modulation sign by R28, R26 and+5V voltage decision, series resistance R33 shunt capacitance C15 again behind the output parallel resistance R46 of operational amplifier, R45, the R32.Compensating circuit is: the output terminating diode D5 connecting resistance R29 of operational amplifier TLE2301, resistance R 30 back ground connection, one end of resistance R 29 and the inverting input of sending into operational amplifier TLE2021 after resistance R 31 is connected, meet diode D6 series resistance R35, R36 again after resistance R 46, R45, the R32 parallel connection, behind resistance R 36 E5 in parallel, the in-phase input end of one termination operational amplifier TLE2021, other end ground connection.
Data receiver circuit: the table meter is when collector transmits data, the electric current trailing edge makes terminal resistance R46, R45, R32 and R33 voltage reduce in the detection electric current arteries and veins slave unit, Schottky diode D4 and resistance R 40, R41 configuration switch threshold together make that the time keeps constant on the electric capacity E2 stored voltage, and it just can recover to pick out this data-signal when comparator LM393 detects a little voltage.
Warning circuit: the voltage after the voltage on the resistance R on the main frame transtation mission circuit 33 is greater than R18 series connection R22, comparator detects this overload signal, and signal is passed to microcontroller, carries out associative operation by microcontroller.
The certificate that M-BUS receives is stored in AT24C256A, and memory module AT24C256A write-protect end WP is connected to the PC3 mouth of microcontroller, and input end of clock SCL is connected with the PC5 mouth of microcontroller, and data terminal SDA is connected to the PC4 mouth of microcontroller.
Up and concentrator carries out the RF radio communication:
Microcontroller with PD7 put high level, when PD5 puts low level, the RF wireless module is in transmit status, data are by the SPI UHF wireless transceiver CC1100 that communicates by letter in the microcontroller, transceiving chip amplifies data signal modulation through antenna transmission to concentrator; Microcontroller is put high level with PD5, and when PD7 put low level, the RF wireless module was in receive status, and external signal receives after transceiving chip is sent in filtering through antenna, and transceiving chip is sent into microcontroller after signal processing, carries out data processing by microcontroller.
Pin SCLK, the SO of transceiving chip, CSn, SI are connected with pin PC4, PC3, PD2, the PC5 of microcontroller after isolating through resistance R 3, R2, R5, R4 respectively, realize the read-write operation of microcontroller to the transceiving chip internal register, C50 is used for to clock signal SCLK filtering to eliminate sharp cutting edge of a knife or a sword pulse; Pin GDO0 is connected with microcontroller pin PC2 after resistance R 1 is isolated, and is used to inform that the microcontroller wireless data been has has been received and dispatched finishes; Pin RF_P, RF_N are the input/output port of radiofrequency signal, C121, C131, L131 and L121 form a balanced to unbalanced transformer, in order to the differential RF port translation on the transceiving chip is become single-ended RF signal, and carry out the antenna of impedance transformation jointly with coupling 500hn in the LC of back network; LC network C 122, C123, L122, L123 are the radio-frequency passband filter, and it is used for filtering the harmonic content and the interference component of radio-frequency transmission signals, make that the signal spectrum of discrepancy transceiving chip is purer; C125 is the direct current module capacitance, is used for stopping direct current.
The wireless data transtation mission circuit: microcontroller PD7 puts high level, PD5 puts low level, capacitor C 125 connects 5 pin of U5,3 pin of AS169 connect an end of capacitor C 225, the grid of another termination field effect transistor of C225, ground connection behind while C225 series resistance R204, the R205, the drain electrode of field effect transistor is through connecing on 3 pin of U4 after inductance L 203, the capacitor C 218.
The wireless data receiving circuit: microcontroller PD7 puts low level, PD5 puts high level, be connected to the collector electrode of Q2 behind the 1 foot meridian capacitor C226 of U5, collector electrode is ground connection after inductance L 210, capacitor C 233, the base stage of Q2 is connected to the emitter of Q3 after resistance R 214, resistance R 215 series connection, the base stage of Q2 is connected to 1 pin of U4 after inductance L 209, capacitor C 232 series connection, 6 pin of U4 are connected with the PD7 pin of microcontroller through resistance R 202,4 pin of U4 are connected with the PD5 of microcontroller through resistance R 203, and 5 pin of U4 connect antenna behind filter capacitor C217.