TIAB SA 451
WIRELESS M-BUS SOFTWARE Implementation
Taw qhia
Daim ntawv thov no piav qhia txog kev siv Silicon Labs ntawm Wireless M-Bus siv Silicon Labs C8051 MCU thiab EZRadioPRO®. Wireless M-bus yog European Standard rau kev nyeem ntawv nyeem ntawv siv 868 MHz zaus band.
Txheej Txheej
Wireless M-Bus siv 3-txheej IEC qauv, uas yog ib feem ntawm 7-txheej OSI qauv (saib daim duab 1).
Cov txheej txheem lub cev (PHY) yog txhais hauv EN 13757-4. Lub cev txheej txheej txhais tau li cas cov khoom raug encoded thiab xa mus, RF modem yam ntxwv (chip tus nqi, preamble, thiab synchronization lo lus), thiab RF tsis (modulation, center zaus, thiab zaus sib txawv).
PHY txheej yog siv los ntawm kev sib xyaw ntawm cov khoom siv kho vajtse thiab firmware. EZRadioPRO ua txhua yam ntawm RF thiab modem ua haujlwm. EZRadioPRO yog siv nyob rau hauv FIFO hom nrog lub pob ntawv tuav. MbusPhy.c module muab SPI interface, encoding / decoding, thaiv kev nyeem / sau, thiab ntim ntim thiab tswj cov transceiver xeev.
Cov txheej txheem M-Bus Cov ntaub ntawv txuas tau siv hauv MbusLink.c module. M-Bus Application Programming interface muaj cov haujlwm pej xeem uas yuav raug hu los ntawm cov ntawv thov txheej hauv cov xov tseem ceeb. MbusLink module kuj tseem siv cov Data Link Layer. Cov ntaub ntawv txuas txheej yuav tsim thiab luam cov ntaub ntawv los ntawm daim ntawv thov TX tsis rau MbusPhy TX tsis, ntxiv cov headers thiab CRCs.
Daim ntawv thov txheej nws tus kheej tsis yog ib feem ntawm M-bus firmware. Daim ntawv thov txheej txhais tau li cas ntau yam ntawm cov ntaub ntawv yuav tsum tau formatted rau kev sib kis. Feem ntau cov meters tsuas yog yuav tsum xa ib lossis ob hom ntaub ntawv. Ntxiv cov lej loj kom haum rau txhua yam ntaub ntawv rau lub ntsuas yuav ntxiv cov lej tsis tsim nyog thiab tus nqi rau lub ntsuas. Tej zaum nws yuav ua tau los siv lub tsev qiv ntawv lossis ib lub hauv paus file nrog rau tag nrho cov npe ntawm cov ntaub ntawv hom. Txawm li cas los xij, feem ntau metering cov neeg siv khoom paub tseeb tias hom ntaub ntawv twg lawv xav tau xa mus thiab tuaj yeem xa mus rau tus qauv rau cov ntsiab lus formatting. Ib tus neeg nyeem ntawv thoob ntiaj teb lossis tus neeg sniffer tuaj yeem siv ua tiav cov ntaub ntawv thov cov ntaub ntawv ntawm PC GUI. Rau cov laj thawj no, daim ntawv thov txheej yog siv los ntawm example daim ntaub ntawv rau ib lub 'meter' thiab nyeem ntawv.
Yuav tsum muaj cov qauv
- TS EN 13757-4
TS EN 13757-4
Kev sib txuas lus rau ntsuas ntsuas thiab nyeem tej thaj chaw deb ntawm meters
Part 4: Wireless meter readout
Kev nyeem ntawv xov tooj cua rau kev ua haujlwm hauv 868 MHz txog 870 MHz SRD band - TS EN 13757-3
Kev sib txuas lus rau ntsuas ntsuas thiab nyeem tej thaj chaw deb ntawm meters
Part 3: Dedicated daim ntawv thov txheej - IEC 60870-2-1: 1992
Telecontrol cov cuab yeej thiab cov tshuab
Ntu 5: Cov kev cai sib kis
Tshooj 1: Txuas cov txheej txheem sib kis - IEC 60870-1-1: 1990
Telecontrol cov cuab yeej thiab cov tshuab
Ntu 5: Cov kev cai sib kis
Kauj Ruam 1: Kev xa tawm cov qauv
Lus txhais
- M-Bus—M-Bus yog ib qho qauv siv rau kev nyeem ntawv ntsuas hauv Europe.
- Wireless M-Bus-Wireless M-Bus rau meter nyeem ntawv hauv Tebchaws Europe.
- PHY-Lub cev txheej txheej txhais li cas cov ntaub ntawv cov khoom thiab cov bytes tau encoded thiab xa mus.
- API-Daim ntawv thov Programmer interface.
- LINK—Data Link Layer txhais li cas blocks thiab thav ntawv raug xa mus.
- CRC—Cyclic Redundancy Check.
- FSK—Frequency Shift Keying.
- Chip—Qhov tsawg tshaj plaws ntawm cov ntaub ntawv kis tau tus mob. Ib cov ntaub ntawv me ntsis yog encoded li ntau chips.
- Module—AC code qhov chaw .c file.
M-Bus PHY Functional Description
Preamble Sequence
Qhov Preamble ib ntus teev los ntawm M-bus specification yog tus lej lej sib hloov zeros thiab ib qho. Ib qho yog txhais raws li qhov ntau zaus, thiab xoom txhais tau tias yog qhov qis dua.
nx (01)
Cov kev xaiv Preamble rau Si443x yog tus lej ntawm cov nibbles suav nrog kev hloov pauv thiab xoom.
nx (1010)
Ib tug preamble nrog ib tug ntxiv coj ib tug yuav tsis muaj teeb meem, tab sis, ces, synchronization lo lus thiab payload yuav misaligned los ntawm ib tug me ntsis.
Txoj kev daws teeb meem yog hloov pauv tag nrho cov pob ntawv los ntawm kev teeb tsa lub cav me ntsis hauv Modulation Control 2 sau npe (0x71). Qhov no yuav hloov pauv cov lus ua ntej, synchronize lo lus, thiab TX/RX cov ntaub ntawv. Raws li qhov tshwm sim, cov ntaub ntawv yuav tsum tau hloov pauv thaum sau cov ntaub ntawv TX lossis nyeem cov ntaub ntawv RX. Tsis tas li ntawd, cov lus synchronization yog inverted ua ntej sau ntawv rau Si443x Synchronization Word sau npe.
Synchronization Lo lus
Cov lus synchronization xav tau los ntawm EN-13757-4 yog 18 chips rau Hom S thiab Hom R lossis 10 chips rau Model T. Cov lus synchronization rau Si443x yog 1 mus rau 4 bytes. Txawm li cas los xij, txij li lo lus synchronization yeej ib txwm ua ntej los ntawm preamble, lub xeem rau lub ntsiab lus tuaj yeem suav tias yog ib feem ntawm cov lus synchronization; yog li ntawd, thawj cov lus synchronization yog padded los ntawm peb repetitions ntawm ib tug xoom ua raws li los ntawm ib tug. Cov lus synchronization tau ua tiav ua ntej sau ntawv rau Si443x sau npe.
Table 1. Synchronization Lo lus rau hom S thiab hom R
| TS EN 13757-4 | 00 | 01110110 | 10010110 | binary |
| 00 | 76 | 96 | xis hex | |
| pad nrog (01) x 3 | 01010100 | 01110110 | 10010110 | binary |
| 54 | 76 | 96 | xis hex | |
| ntxiv | 10101011 | 10001001 | 01101001 | binary |
| AB | 89 | 69 | xis hex |
Rooj 2. Synchronization Lo lus rau hom T Meter rau lwm yam
| SYNCH | SYNCH | SYNCH |
| Lo lus | Lo lus | Lo lus |
| 3 | 2 | 1 |
Hloov Preamble Length
Yam tsawg kawg preamble yog teev rau plaub hom kev khiav hauj lwm sib txawv. Nws raug pom zoo kom muaj qhov preamble ntev dua li teev. Kev rho tawm rau lub chips rau lub preamble muab qhov tsawg kawg nkaus ntawm chips rau Si443x preamble. Qhov kev siv ntxiv ob qho ntxiv nibbles ntawm preamble nyob rau hauv tag nrho cov luv preamble hom los txhim kho preamble nrhiav thiab interoperability. Lub preamble ntawm hom S nrog ib tug ntev preamble yog ntev heev; yog li ntawd, qhov tsawg kawg nkaus preamble yog siv. Lub preamble ntev hauv nibbles yog sau rau Preamble Length (0x34) sau npe. Lub preamble ntev register txiav txim lub preamble raws li kis tau tus mob nkaus xwb. Yam tsawg kawg nkaus specification thiab preamble length settings yog sau nyob rau hauv Table 3.
Table 3. Transmit Preamble Length
| EN-13757-4 yam tsawg kawg nkaus |
Si 443 x Preamble Teeb ib |
Sync Lo lus |
Tag nrho | ntxiv | |||
| nx (01) | chips | nibbles | chips | chips | chips | chips | |
| Hom S luv preamble | 15 | 30 | 8 | 32 | 6 | 38 | 8 |
| Hom S ntev preamble | 279 | 558 | 138 | 552 | 6 | 558 | 0 |
| Hom T (meter-lwm yam) | 19 | 38 | 10 | 40 | 6 | 46 | 8 |
| Hom R | 39 | 78 | 20 | 80 | 6 | 86 | 8 |
Qhov tsawg kawg nkaus preamble rau txais tos yog txiav txim los ntawm Preamble Detection Control register (0x35). Thaum txais tos, tus naj npawb ntawm cov khoom nyob rau hauv cov lus sync yuav tsum tau muab rho tawm los ntawm qhov tsawg kawg nkaus preamble los txiav txim qhov siv tau preamble. Qhov tsawg kawg nkaus lub sij hawm ntawm lub receiver yog 16-chips yog AFC enabled los yog 8-chips yog AFC neeg xiam. Lub sij hawm txais kev daws teeb meem kuj raug rho tawm los ntawm qhov siv tau ua ntej los txiav txim qhov tsawg kawg nkaus rau Preamble Detection Control register.
Qhov tshwm sim ntawm qhov tsis tseeb preamble nyob ntawm qhov chaw ntawm Preamble Detection Control register. Kev teeb tsa luv luv ntawm 8-chis tuaj yeem ua rau qhov tsis tseeb preamble pom txhua ob peb feeb. Qhov pom zoo teeb tsa ntawm 20chips ua rau qhov tsis tseeb preamble nrhiav pom qhov tshwm sim tsis zoo. Lub preamble lengths rau hom R thiab hom SL yog ntev txaus rau qhov pom zoo teeb tsa siv.
Muaj qhov txiaj ntsig me me heev los ua qhov preamble ntes ntev dua 20 chips.
AFC yog neeg xiam oob khab rau Model S nrog luv preamble thiab Model T. Qhov no yuav txo tau lub receiver settling lub sij hawm thiab tso cai rau ib tug ntev preamble nrhiav teeb meem. Nrog AFC neeg tsis taus, Hom T tuaj yeem siv qhov kev pom zoo ntawm 20 chips. Qhov chaw ntawm 4 nibbles lossis 20 chips yog siv rau Model S nrog luv luv preamble. Qhov no ua rau qhov tshwm sim ntawm qhov tsis tseeb preamble nrhiav pom me ntsis siab dua rau cov qauv no.
Table 4. Preamble Detection
| EN-13757-4 yam tsawg kawg nkaus |
Sync Lo lus |
siv tau lus qhuab qhia |
RX Kev daws teeb meem | Tshawb pom min |
Si 443 x Preamble Nrhiav Kom Tau Lub Teeb |
|||
| nx (01) | chips | chips | chips | chips | chips | nibbles | chips | |
| Hom S luv preamble | 15 | 30 | 6 | 24 | 8* | 16 | 4 | 16 |
| Model S ntev preamble | 279 | 558 | 6 | 552 | 16 | 536 | 5 | 20 |
| Qauv T (meter-lwm yam) | 19 | 38 | 6 | 32 | 8* | 24 | 5 | 20 |
| Hom R | 39 | 78 | 6 | 72 | 16 | 56 | 5 | 20 |
| * Nco tseg: AFC neeg xiam | ||||||||
Lub receiver yog configured interoperate nrog ib tug transmitter siv qhov tsawg kawg nkaus teev preamble. Qhov no ua kom lub receiver yuav cuam tshuam nrog ib qho M-bus-raws li transmitter.
Lub Wireless M-Bus specification yuav tsum muaj lub preamble ntev heev rau hom S1 ntawm tsawg kawg yog 558 chips. Qhov no yuav siv li ntawm 17 ms xwb los xa cov lus piv txwv. Si443x tsis xav tau cov lus qhuab qhia ntev ntev thiab tsis tau txais txiaj ntsig los ntawm qhov ntev preamble. Thaum lub sij hawm ntev preamble raug sau tseg raws li kev xaiv rau hom S2, tsis muaj laj thawj siv lub preamble ntev nrog Si443x. Yog xav tau kev sib txuas lus ib-txoj kev, hom T1 yuav muab ib tug luv luv preamble, cov ntaub ntawv ntau dua, thiab ntev roj teeb lub neej. Yog hais tias ob txoj kev sib txuas lus siv hom S2 yog yuav tsum tau, ib tug luv luv preamble yog pom zoo.
Daim ntawv ceeb toom tias qhov kev tshawb pom qhov pib rau Model S nrog lub preamble ntev ntev tshaj li tus naj npawb ntawm preamble nibbles kis rau Model S nrog ib tug luv luv preamble. Qhov no txhais tau hais tias qhov ntev preamble Mode S receiver yuav tsis ntes ib tug preamble los ntawm ib tug luv preamble hom S transmitter. Qhov no yog qhov tsim nyog yog tias qhov ntev preamble Hom S txais yuav tau txais txiaj ntsig los ntawm qhov ntev preamble.
Nco ntsoov tias qhov luv preamble Mode S txais yuav ntes cov preamble thiab tau txais pob ntawv los ntawm ob qho tib si luv preamble hom S
transmitter thiab ntev-preamble hom S transmitter; Yog li, feem ntau, tus nyeem ntawv ntsuas yuav tsum siv qhov luv preamble Hom S receiver configuration.
Encoding/Decoding
Wireless M-bus specification yuav tsum muaj ob txoj kev sib txawv encoding. Manchester encoding yog siv rau hom S thiab hom R. Manchester encoding kuj yog siv rau lwm qhov-rau-meter txuas hauv Model T. Tus qauv T meter-rau-lwm txuas siv 3 tawm ntawm 6 encodings.
1. Manchester Encoded/Decoding
Manchester encoding yog ib txwm muaj keeb kwm hauv RF systems los muab lub moos zoo rov qab thiab taug qab siv lub modem yooj yim thiab pheej yig. Txawm li cas los xij, lub xov tooj cua niaj hnub ua haujlwm siab zoo li Si443x tsis xav tau Manchester encoding. Manchester encoding tau txais kev txhawb nqa feem ntau rau kev sib raug zoo nrog cov qauv uas twb muaj lawm, tab sis cov ntaub ntawv tus nqi rau Si443x tau zoo dua ob npaug thaum tsis siv Manchester encoding.
Si443x txhawb Manchester encoding thiab decoding ntawm tag nrho cov pob ntawv hauv kho vajtse. Hmoov tsis zoo, lo lus synchronization tsis yog Manchester encoded. Ib qho tsis raug Manchester ib ntus tau txhob txwm xaiv rau lo lus synchronization. Qhov no ua rau Manchester encoding tsis sib haum nrog feem ntau cov xov tooj cua uas twb muaj lawm, suav nrog Si443x. Raws li qhov tshwm sim, Manchester encoding thiab decoding yuav tsum tau ua los ntawm MCU. Txhua byte ntawm unencoded cov ntaub ntawv muaj yim cov ntaub ntawv khoom. Siv Manchester encoding, txhua cov ntaub ntawv me ntsis yog encoded rau hauv ob lub cim cim. Txij li thaum cov ntaub ntawv encoded yuav tsum tau sau rau hauv xov tooj cua FIFO yim nti ntawm ib lub sij hawm, ib qho nibble ntawm cov ntaub ntawv yog encoded thiab sau rau FIFO ib zaug.
Table 5. Manchester Encoding
| cov ntaub ntawv | Txh12 | 0 x 34 | bytes | ||
| Txh1 | 0 x 2 | 0 x 3 | 0 x 4 | nibbles | |
| 1 | 10 | 11 | 100 | binary | |
| nti | 10101001 | 10100110 | 10100101 | 10011010 | binary |
| FIFO | OxA 9 | OxA 6 | OxA 5 | Tx9a | xis hex |
Txhua byte yuav kis tau dhau ib byte ntawm ib lub sij hawm rau encode byte muaj nuj nqi. Lub encode byte muaj nuj nqi yuav hu rau encode nibble muaj nuj nqi ob zaug, ua ntej rau qhov tseem ceeb tshaj plaws nibble thiab tom qab ntawd rau qhov tsawg kawg nkaus nibble.
Manchester encoding hauv software tsis yooj yim. Pib los ntawm qhov tseem ceeb tshaj plaws me ntsis, ib qho yog encoded li "01" nti ntu. Lub xoom yog encoded raws li "10" nti ntu. Qhov no tuaj yeem ua tiav yooj yim siv lub voj thiab hloov ob-ntsis rau txhua lub cim. Txawm li cas los xij, nws tau nrawm dua los tsuas yog siv qhov yooj yim 16 nkag mus saib lub rooj rau txhua qhov nibble. Lub encode Manchester nibble muaj nuj nqi encodes ib nibble ntawm cov ntaub ntawv ces sau nws mus rau FIFO. Cov chips yog inverted ua ntej sau ntawv mus rau FIFO rau account rau inverted preamble yuav tsum.
Thaum tau txais, txhua byte hauv FIFO muaj yim nti thiab txiav txim siab rau hauv ib lub nibble ntawm cov ntaub ntawv. Kev nyeem thaiv kev ua haujlwm nyeem ib byte ntawm ib lub sijhawm los ntawm FIFO thiab hu rau decode byte muaj nuj nqi. Cov chips yog inverted tom qab nyeem ntawv los ntawm FIFO rau account rau inverted preamble yuav tsum. Txhua byte ntawm Manchester encoded chips yog txiav txim siab rau hauv cov ntaub ntawv nibble. Qhov kev txiav txim siab nibble yog sau rau RX tsis siv tus sau nibble RX tsis muaj nuj nqi.
Daim ntawv ceeb toom tias ob qho tib si encoded thiab decoding tau ua ib cov ntaub ntawv nibble ntawm ib lub sij hawm ntawm ya. Kev nkag mus rau qhov tsis yuav xav tau qhov tsis muaj ntxiv ob zaug ntawm qhov loj ntawm cov ntaub ntawv tsis tau sau. Encoding thiab decoding yog nrawm dua li cov ntaub ntawv txhawb nqa ceev tshaj plaws (100 k chips ib ob). Txij li thaum Si443x txhawb nqa ntau-byte nyeem thiab sau rau FIFO, muaj qhov nyiaj siv me me hauv kev siv tib-byte nyeem thiab sau. Qhov nyiaj siv ua haujlwm yog li 10 µs rau 100 encoded chips. Qhov txiaj ntsig yog RAM txuag ntawm 512 bytes.
2. Peb Tawm ntawm Six encoding decoding
Peb-tawm-ntawm-Six encoding txoj kev tau teev tseg hauv EN-13757-4 kuj tau siv hauv firmware ntawm MCU. Qhov no encoding yog siv rau high-ceev (100 k chips ib ob) hom T los ntawm meter mus rau lwm yam. Qauv T muab lub sijhawm luv tshaj plaws thiab lub roj teeb ntev tshaj plaws rau lub ntsuas hluav taws xob wireless.
Txhua byte ntawm cov ntaub ntawv yuav tsum tau muab faib ua ob nibbles. Qhov tseem ceeb tshaj plaws nibble yog encoded thiab kis ua ntej. Ntxiv dua thiab, qhov no yog siv los ntawm kev siv encode byte muaj nuj nqi uas hu rau encode nibble muaj nuj nqi ob zaug.
Txhua nibble ntawm cov ntaub ntawv yog encoded rau hauv lub cim rau-chip. Cov cim ntawm rau-chip cim yuav tsum tau sau rau 8chip FIFO.
Thaum lub sij hawm encoding, ob bytes ntawm cov ntaub ntawv yog encoded li plaub nibbles. Txhua nibble yog 6-chip cim. Plaub 6chip cim tau sau ua peb bytes.
Table 6. Peb Tawm ntawm Six Encoding
| cov ntaub ntawv | 0 x 12 | 0 x 34 | bytes | ||||
| Txh1 | 0 x 2 | 0 x 3 | 0 x 4 | nibbles | |||
| nti | 15 | 16 | 13 | 34 | octal | ||
| 1101 | 1110 | 1011 | 11100 | binary | |||
| FIFO | 110100 | 11100010 | 11011100 | binary | |||
| 0 x 34 | OxE 2 | OxDC | xis hex | ||||
Hauv software, peb-tawm-ntawm-rau-tus encoding yog siv los ntawm peb lub zes ua haujlwm. Lub encode byte muaj nuj nqi yuav hu rau lub encode nibble muaj nuj nqi ob zaug. Lub encode nibble muaj nuj nqi siv lub rooj saib rau lub cim rau lub cim thiab sau lub cim mus rau Hloov Peb ntawm Six lub luag haujlwm. Qhov kev ua haujlwm no siv 16-chip hloov npe hauv software. Lub cim yog sau rau qhov tsawg kawg nkaus byte ntawm kev hloov npe. Daim ntawv teev npe tau hloov mus rau sab laug ob zaug. Qhov no rov ua peb zaug. Thaum ib tug ua tiav byte tam sim no nyob rau sab sauv byte ntawm lub npe hloov, nws yog inverted thiab sau rau FIFO.
Txij li txhua byte ntawm cov ntaub ntawv yog encoded raws li ib thiab ib nrab encoded bytes, nws yog ib qho tseem ceeb kom tshem tawm cov hloov pauv thawj zaug kom thawj encoded byte yog lawm. Yog tias qhov ntev ntawm pob ntawv yog tus lej khib, tom qab encoding tag nrho bytes, tseem yuav muaj ib qho nibble sab laug hauv kev hloov pauv. Qhov no yog daws nrog lub postamble raws li tau piav qhia hauv tshooj tom ntej.
Decoding peb tawm ntawm rau encoded yog tus txheej txheem thim rov qab. Thaum decoding, peb encoded bytes decoded rau hauv ob cov ntaub ntawv bytes. Lub software hloov npe rov siv dua los sau cov bytes ntawm cov ntaub ntawv txiav tawm. Ib lub rooj 64-nkag rov qab saib lub rooj yog siv rau kev txiav txim siab. Qhov no siv tsawg lub voj voog tab sis ntau tus lej cim xeeb. Kev tshawb nrhiav 16-nkag nkag saib lub rooj rau cov cim sib thooj yuav siv sijhawm ntev dua.
Postamble
Lub Wireless M-bus specification muaj cov kev cai tshwj xeeb rau lub postamble lossis trailer. Rau txhua hom, qhov tsawg kawg nkaus yog ob lub chips, thiab qhov siab tshaj plaws yog yim nti. Txij li thaum qhov tsawg kawg nkaus atomic unit rau FIFO yog ib byte, ib tug 8-chip trailer yog siv rau hom S thiab hom R. Hom T postamble yog yim chips yog hais tias lub pob ntawv ntev yog txawm los yog plaub chips yog hais tias lub pob ntawv ntev yog khib. Plaub-chip postamble rau qhov txawv pob ntawv ntev raws li qhov yuav tsum tau muaj tsawg kawg yog ob daim ntawv hloov pauv.
Rooj 7. Postamble Length
| Postamble Length (chips) | |||||
| min | max | Kev nqis tes ua | chip kab | ||
| Hom S | 2 | 8 | 8 | 1010101 | |
| Hom T | 2 | 8 | 4 | (kawg) | 101 |
| 8 | (txawm) | 1010101 | |||
| Hom R | 2 | 8 | 8 | 1010101 | |
Packet Handler
Lub pob ntawv tuav ntawm Si443x tuaj yeem siv rau hauv qhov sib txawv pob ntawv dav hom lossis hom pob ntawv ruaj khov. Qhov sib txawv pob ntawv dav hom xav tau pob ntawv ntev byte tom qab cov lus synchronization thiab xaiv tau header bytes. Thaum txais tos, Xov Tooj Cua yuav siv qhov ntev byte los txiav txim qhov kawg ntawm pob ntawv siv tau. Thaum kis tau tus mob, lub xov tooj cua yuav ntxig qhov ntev teb tom qab header bytes.
L teb rau lub wireless M-bus raws tu qauv siv tsis tau rau Si443x ntev teb. Ua ntej, L teb tsis yog qhov ntev ntawm pob ntawv. Nws yog tus lej ntawm qhov txuas txheej payload bytes tsis suav nrog CRC bytes lossis encoding. Qhov thib ob, L -field nws tus kheej yog encoded siv Manchester encoding lossis Peb tawm ntawm Six encoding rau hom T meter mus rau lwm yam.
Qhov kev siv siv lub pob ntawv tuav hauv cov pob ntawv ruaj khov dav rau ob qho tib si kis tau tus mob thiab txais tos. Thaum kis tau tus mob, PHY txheej yuav nyeem L daim teb hauv qhov kev xa tawm tsis thiab suav cov lej ntawm cov lej uas tau sau tseg, suav nrog cov ntawv xa tawm. Tag nrho cov naj npawb ntawm cov lej encoded uas yuav kis tau yog sau rau hauv pob ntawv Length register (0x3E).
Thaum txais tos, thawj ob lub bytes encoded yog txiav txim siab, thiab L-field tau sau rau qhov tsis tau txais. L-field yog siv los xam cov lej ntawm cov lej encoded yuav tsum tau txais. Tus naj npawb ntawm encoded bytes yuav tsum tau txais yog tom qab ntawd sau rau pob ntawv Length sau npe (0x3E). Lub postamble yog muab pov tseg.
MCU yuav tsum txiav txim siab L-field, suav cov lej ntawm cov lej uas tau muab sau tseg, thiab sau tus nqi mus rau Packet Length sau npe ua ntej qhov luv tshaj plaws tau txais pob ntawv ntev. Qhov luv tshaj tso cai L- teb rau PHY txheej yog 9, muab 12 unencoded bytes. Qhov no muab 18 encoded bytes rau Model T. Thawj ob bytes twb tau decoded. Yog li, pob ntawv Length sau npe yuav tsum tau hloov kho hauv 16-byte zaus ntawm 100 kbps lossis 1.28 milliseconds. Qhov no tsis muaj teeb meem rau 8051 khiav ntawm 20 MIPS.
Tus naj npawb ntawm bytes yuav tsum tau txais tsis suav nrog cov ntawv xa tawm, tshwj tsis yog rau plaub-chip postamble siv rau hom T pob ntawv nrog qhov txawv pob ntawv ntev. Yog li, tus txais yuav tsis xav tau ib qho postamble, tsuas yog rau cov qauv T khib ntev pob ntawv. Qhov kev tshaj tawm no tsuas yog xav tau los muab tus lej lej ntawm cov lej encoded. Cov ntsiab lus ntawm postamble yog ignored; yog li ntawd, yog tias tsis muaj kev xa tawm, plaub lub suab nrov yuav tau txais thiab tsis quav ntsej. Txij li tag nrho cov naj npawb ntawm encoded bytes yog txwv rau 255 (0xFF), qhov kev siv txwv qhov siab tshaj plaws L-field rau ntau hom.
Table 8. Packet Size txwv
| encoded | txiav txim siab | M-Bus | ||||
| bytes | bytes | L-Field | ||||
| dec | xis hex | dec | xis hex | dec | xis hex | |
| Hom S | 255 | FF | 127 | 7f ua | 110 | 6E |
| Hom T (meter-lwm yam) | 255 | FF | 169 | A9 | 148 | 94 |
| Hom R | 255 | FF | 127 | 7f ua | 110 | 6E |
Cov kev txwv no feem ntau zoo tshaj qhov kev siv cov ntaub ntawv rau lub ntsuas hluav taws xob wireless. Lub pob ntawv ntev yuav tsum khaws cia me me kom tau txais lub roj teeb zoo tshaj plaws.
Tsis tas li ntawd, tus neeg siv yuav qhia qhov siab tshaj plaws L- teb uas yuav tsum tau txais (USER_RX_MAX_L_FIELD). Qhov no txiav txim siab qhov loj me rau qhov tau txais tsis (USER_RX_BUFFER_SIZE).
Txhawb nqa qhov siab tshaj plaws L-field ntawm 255 yuav tsum tau txais qhov tsis txaus ntawm 290 bytes thiab qhov siab tshaj plaws ntawm 581 Manchester encoded bytes. Tus neeg tuav pob ntawv yuav tsum tau ua tsis taus thiab Daim Ntawv Teev Npe Lub Ncauj Ntev tsis tuaj yeem siv rau qhov ntawd. Qhov no yog qhov ua tau, tab sis nws yooj yim dua los siv lub hnab ntim khoom, yog tias ua tau.
Kev siv FIFO
Si4431 muab 64 byte FIFO rau kev xa thiab tau txais. Txij li tus naj npawb ntawm encoded bytes yog 255, tag nrho cov ntawv encoded yuav tsis haum rau hauv 64-byte tsis.
Kev sib kis
Thaum kis tau tus mob, tag nrho cov lej ntawm encoded bytes raug xam. Yog tias tag nrho cov lej ntawm cov lej encoded, suav nrog cov ntawv xa tawm, tsawg dua 64 bytes, tag nrho cov pob ntawv tau sau rau FIFO thiab tsuas yog pob ntawv xa tuaj cuam tshuam tau qhib. Feem ntau cov pob ntawv luv luv yuav raug xa mus rau hauv ib qho kev hloov FIFO.
Yog hais tias tus naj npawb ntawm cov encoded bytes ntau dua 64, ntau FIFO hloov tsheb yuav tsum tau xa cov pob ntawv. Thawj 64 bytes tau sau rau FIFO. Cov pob ntawv xa thiab TX FIFO Yuav luag tsis muaj kev cuam tshuam tau qhib. TX FIFO Yuav luag tsis muaj qhov pib yog teem rau 16 bytes (25%). Thaum txhua qhov kev tshwm sim IRQ, cov xwm txheej 2 sau npe tau nyeem. Cov pob ntawv xa me ntsis raug kuaj ua ntej, thiab, yog tias pob ntawv tsis tau xa tag nrho, tom ntej 48 bytes ntawm cov ntaub ntawv encoded raug sau rau FIFO. Qhov no txuas ntxiv mus txog rau thaum tag nrho cov kab ntawv encoded tau sau thiab Packet Xa cuam tshuam tshwm sim.
1. Kev txais tos
Ntawm kev txais tos, thawj zaug, tsuas yog Sync Lo Lus cuam tshuam tau qhib. Tom qab tau txais cov lus synchronization, lub sync lo lus cuam tshuam yog neeg xiam thiab FIFO Yuav luag Tag Nrho cuam tshuam tau qhib. FIFO yuav luag tag nrho cov pib pib pib rau 2 bytes. Thawj FIFO Yuav luag Tag Nrho cuam tshuam yog siv los paub thaum twg ob qhov ntev bytes tau txais. Thaum qhov ntev tau txais, qhov ntev yog txiav txim siab thiab tus lej ntawm cov lej encoded raug suav. RX FIFO yuav luag tag nrho qhov pib yog ces teem rau 48 bytes. RX FIFO yuav luag tag nrho thiab siv tau pob ntawv cuam tshuam tau qhib. Thaum qhov kev tshwm sim IRQ tom ntej, cov xwm txheej 1 sau npe tau nyeem. Ua ntej, cov pob ntawv siv tau me ntsis raug kuaj xyuas, thiab tom qab ntawd FIFO Yuav luag Tag Nrho tau kuaj xyuas. Yog tias tsuas yog RX FIFO Yuav luag tag nrho tau teeb tsa, tom ntej 48 bytes tau nyeem los ntawm FIFO. Yog tias lub pob ntawv siv tau raug teeb tsa, qhov seem ntawm pob ntawv raug nyeem los ntawm FIFO. MCU khaws cov ntaub ntawv ntau npaum li cas tau nyeem thiab nres nyeem tom qab byte kawg.
Cov Ntaub Ntawv Txuas Txheej
Cov ntaub ntawv txuas txheej module siv 13757-4: 2005 raws li txheej txuas. Cov ntaub ntawv txuas txheej (LINK) muab qhov sib txuas ntawm lub cev txheej (PHY) thiab daim ntawv thov txheej (AL).
Data Link Layer ua cov haujlwm hauv qab no:
- Muab cov haujlwm uas hloov cov ntaub ntawv ntawm PHY thiab AL
- Tsim CRCs rau cov lus tshaj tawm
- Pom CRC yuam kev hauv cov lus xa tuaj
- Muab qhov chaw nyob ntawm lub cev
- lees paub kev hloov pauv rau hom kev sib txuas lus bidirectional
- Ncej cov ntaub ntawv me ntsis
- Nthuav framing yuam kev hauv cov lus tuaj
Txuas Layer Frame Format
Wireless M-Bus thav duab hom siv nyob rau hauv EN 13757-4: 2005 yog muab los ntawm FT3 (Frame Type 3) thav duab hom los ntawm IEC60870-5-2. Lub thav duab muaj ib lossis ntau qhov thaiv ntawm cov ntaub ntawv. Txhua qhov thaiv suav nrog 16-ntsis CRC teb. Thawj pob khoom yog qhov ntev-ntev thaiv ntawm 12 bytes uas suav nrog L-field, C-field, M-field, thiab A-Field.
- L-Field
L-field yog qhov ntev ntawm Link txheej cov ntaub ntawv them nyiaj. Qhov no tsis suav nrog L-field nws tus kheej lossis ib qho ntawm CRC bytes. Nws suav nrog L-field, C-field, M-field, thiab A-Field. Cov no yog ib feem ntawm PHY payload.
Vim hais tias tus naj npawb ntawm encoded bytes raug txwv rau 255 bytes, qhov siab tshaj plaws kev txhawb nqa tus nqi rau M-field yog 110 bytes rau Manchester encoded cov ntaub ntawv thiab 148 bytes rau hom T Peb-tawm-ntawm-rau-cov ntaub ntawv encoded.
Cov txheej txuas yog lub luag haujlwm rau kev suav L- teb ntawm kev sib kis. Qhov txuas-txheej yuav siv L- teb ntawm kev txais tos.
Nco ntsoov lub L-field tsis qhia qhov PHY payload ntev lossis tus lej ntawm cov lej ntawm cov lej. Thaum kis tau tus mob, PHY yuav xam qhov PHY payload ntev thiab tus naj npawb ntawm cov lej ntawm cov lej. Thaum txais tos, PHY yuav txiav txim siab L- teb thiab suav cov lej ntawm bytes los txiav txim siab. - C- teb
C-field yog lub thav duab tswj teb. Daim teb no txheeb xyuas hom thav duab thiab yog siv rau kev sib txuas cov ntaub ntawv sib pauv kev pabcuam primitives. C- teb qhia hom thav duab - Xa, lees paub, thov, lossis teb. Nyob rau hauv cov ntaub ntawv ntawm SEND thiab REQUEST thav duab, C- teb qhia seb puas yuav tsum tau CONFIRM los yog teb.
Thaum siv qhov yooj yim Link TX muaj nuj nqi, txhua tus nqi ntawm C tuaj yeem siv tau. Thaum siv Link Service Primitives, C teb yog populated cia li raws li EN 13757-4: 2005. - M-Field
M-field yog tus tsim cov cai. Cov neeg tsim khoom tuaj yeem thov tus lej peb tsab ntawv los ntawm cov hauv qab no web chaw nyob: http://www.dlms.com/flag/INDEX.HTM Txhua tus cim ntawm peb tsab ntawv code yog encoded li tsib ntsis. 5-ntsis code yuav tau txais los ntawm kev noj ASCII code thiab rho tawm 0x40 ("A"). Peb 5-ntsis codes yog concatenated los ua 15-ntsis. Qhov tseem ceeb tshaj me ntsis yog xoom. - A- Teb
Qhov chaw nyob yog qhov chaw nyob 6-byte tshwj xeeb rau txhua lub cuab yeej. Qhov chaw nyob tshwj xeeb yuav tsum tau muab los ntawm cov chaw tsim khoom. Nws yog lub luag haujlwm ntawm txhua qhov chaw tsim khoom los xyuas kom meej tias txhua lub cuab yeej muaj qhov tshwj xeeb 6-byte chaw nyob. Qhov chaw nyob rau Xa thiab Thov thav ntawv yog qhov chaw nyob ntawm tus kheej ntawm lub 'meter' lossis lwm yam khoom siv. Cov ntaub ntawv lees paub thiab cov lus teb yog xa mus siv qhov chaw nyob ntawm lub hauv paus chiv keeb. - CI-Field
CI-field yog daim ntawv thov header thiab qhia txog hom ntaub ntawv hauv daim ntawv thov cov ntaub ntawv them nyiaj. Thaum EN13757-4: 2005 qhia txog tus lej tsawg ntawm qhov tseem ceeb, Link Service Primitives yuav tso cai rau txhua tus nqi siv. - CRC
CRC tau teev tseg hauv EN13757-4: 2005.
CRC Polynomial yog:
X 16 + x 13 + x 12 + x 11 + x 10 + x8 + x6 + x5 + x2 + 1
Nco ntsoov tias M-Bus CRC suav nrog txhua 16-byte block. Qhov tshwm sim yog tias txhua 16 bytes ntawm cov ntaub ntawv xav tau 18 bytes xa mus,
Cov ntaub ntawv ntxiv
Yog xav paub ntxiv txog Kev Siv Cov Txheej Txheem Txuas Txuas, saib "AN452: Wireless M-Bus Stack Programmers Guide".
Tswj fais fab
Daim duab 2 qhia lub sijhawm tswj fais fab rau ib lub meter example siv hom T1.
MCU yuav tsum nyob rau hauv hom pw tsaug zog thaum twg los tau kom txuag tau lub zog. Hauv no example, MCU tsaug zog thaum RTC tab tom khiav, thaum tos ntawm lub xov tooj cua siv lead ua pib, thiab thaum xa tawm los ntawm FIFO. MCU yuav sawv los ntawm EZRadioPRO IRQ teeb liab txuas nrog Port Match wake-up.
Thaum xa cov lus ntev tshaj li ib qho thaiv, MCU yuav tsum sawv los sau FIFO (raws li FIFO yuav luag tag nrho cuam tshuam) thiab rov qab mus pw.
MCU yuav tsum nyob rau hauv Idle hom khiav los ntawm lub zog oscillator qis lossis tawg-hom oscillator thaum nyeem los ntawm ADC. ADC xav tau lub moos SAR.
Thaum tsis siv, EZRadioPRO yuav tsum nyob rau hauv Shutdown hom nrog SDN tus pin tsav siab. Qhov no yuav tsum muaj kev sib txuas nrog rau MCU. EZ Xov tooj cua Pro sau npe tsis tau khaws cia hauv hom kaw; Yog li, EZRadioPro yog pib ntawm txhua lub sijhawm RTC. Kev pib xov tooj cua siv tsawg dua 100 µs thiab txuag 400 nA. Qhov no ua rau 10 µJ lub zog txuag, raws li 10-thib ob lub sijhawm.
EZRadioPRO siv lead ua siv li 16 ms rau POR. Qhov no yog ntev txaus los xam CRC rau txog yim blocks. MCU yuav rov qab mus pw yog tias nws ua tiav tag nrho CRCs ua ntej cov siv lead ua tau ruaj khov. Yog tias yuav tsum tau encryption, nws kuj tuaj yeem pib thaum tos ntawm crystal oscillator.
MCU yuav tsum khiav ntawm 20 MHz siv lub zog oscillator rau feem ntau cov dej num. Cov haujlwm uas yuav tsum tau muaj lub sijhawm ua tiav yuav tsum siv qhov tseeb oscillator thiab idle mode tsis yog hom pw tsaug zog. RTC muab kev daws teeb meem txaus rau feem ntau cov haujlwm. Lub sijhawm tswj fais fab rau T2 meter example daim ntawv thov yog qhia hauv daim duab 3.
Kev siv transceiver yuav tsum tau ua kom zoo rau cov xwm txheej ib txwm thaum lub ntsuas hluav taws xob sawv thiab tsis muaj tus nyeem ntawv tam sim no. Qhov tsawg kawg nkaus / qhov siab tshaj plaws ACK timeouts ntev txaus kom nws tuaj yeem siv C8051F930 RTC thiab muab MCU rau hauv hom pw tsaug zog.
Tsim cov kev xaiv yog muab rau cov mains lossis USB-powered nyeem ntawv uas tsis tas yuav siv hom pw tsaug zog. Hom tsis ua haujlwm yuav siv los hloov pw tsaug zog kom USB thiab UART tuaj yeem cuam tshuam MCU.
Simplicity Studio
Ib-nias nkag mus rau MCU thiab cov cuab yeej wireless, cov ntaub ntawv, software, cov tsev qiv ntawv code thiab ntau dua. Muaj rau Windows,
Mac thiab Linux!
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Tsis lees paub
Silicon Labs npaj siab muab cov neeg siv khoom nrog cov ntaub ntawv tseeb, raug, thiab tob tob ntawm txhua qhov khoom siv thiab cov qauv muaj rau cov neeg siv khoom siv thiab software siv lossis npaj siab siv cov khoom siv Silicon Labs. Cov ntaub ntawv tus cwj pwm, muaj cov qauv thiab cov khoom siv, qhov loj me thiab qhov chaw nyob nco tau xa mus rau txhua lub cuab yeej tshwj xeeb, thiab "Tswj" tsis muaj peev xwm muab tau thiab sib txawv hauv ntau daim ntawv thov. Daim ntawv thov examples piav nyob rau hauv no yog rau kev piav qhia nkaus xwb. Silicon Labs muaj txoj cai los hloov pauv yam tsis muaj kev ceeb toom ntxiv thiab txwv rau cov ntaub ntawv khoom, cov lus qhia tshwj xeeb, thiab cov lus piav qhia ntawm no, thiab tsis muab kev lees paub txog qhov raug lossis ua tiav ntawm cov ntaub ntawv suav nrog. Silicon Labs yuav tsis muaj kev lav phib xaub rau qhov tshwm sim ntawm kev siv cov ntaub ntawv muab los ntawm no. Cov ntaub ntawv no tsis hais lossis qhia txog cov ntawv tso cai txwv tsis pub tso cai ntawm no los tsim lossis tsim cov kev sib txuas ua ke. Cov khoom tsis tsim los yog tso cai rau siv nyob rau hauv ib qho Kev Pabcuam Lub Neej yam tsis muaj ntawv tso cai tshwj xeeb ntawm Silicon Labs. Lub "Kev Pabcuam Lub Neej" yog ib yam khoom lossis cov txheej txheem tsim los txhawb lossis txhawb nqa lub neej thiab / lossis kev noj qab haus huv, uas, yog tias nws ua tsis tiav, tuaj yeem ua rau muaj kev raug mob loj lossis tuag. Silicon Labs cov khoom tsis tsim los yog tso cai rau kev siv tub rog. Silicon Labs cov khoom yuav tsum tsis muaj xwm txheej siv rau hauv riam phom ntawm kev puas tsuaj loj xws li (tab sis tsis txwv rau) riam phom nuclear, lom, lossis tshuaj lom neeg, lossis cov foob pob hluav taws muaj peev xwm xa cov riam phom no.
Cov ntaub ntawv lag luam
Silicon Laboratories Inc.®, Silicon Laboratories®, Silicon Labs®, SiLabs®, thiab Silicon Labs logo®, Bluegiga®, Bluegiga Logo®, Clockbuilder®, CMEMS®, DSPLL®, EFM®, EFM32®, EFR, Ember® , Zog Micro, Zog Micro lub logo thiab kev sib txuas ntawm no, "lub ntiaj teb lub zog tshaj plaws tus phooj ywg microcontrollers", Ember®, EZLink®, EZRadio®, EZRadioPRO®, Gecko®, ISOmodem®, Precision32®, ProSLIC®, Simplicity Studio®, SiPHY® , Telegesis, Telegesis Logo®, USBXpress®, thiab lwm yam yog cov cim lag luam lossis cov npe lag luam ntawm Silicon Labs. ARM, CORTEX, Cortex-M3, thiab ntiv tes xoo yog cov cim lag luam lossis cov cim lag luam ntawm ARM Holdings. Keil yog lub npe lag luam ntawm ARM Limited. Tag nrho lwm yam khoom lossis cov npe khoom lag luam uas tau hais hauv no yog cov cim lag luam ntawm lawv cov neeg tuav khoom.
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Cov ntaub ntawv / Cov ntaub ntawv
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SILICON LABS Wireless M-BUS Software Implementation AN451 [ua pdf] Cov neeg siv phau ntawv qhia SILICON LABS, C8051, MCU, thiab, EZRadioPRO, Wireless M-bus, Wireless, M-BUS, Software, Implementation, AN451 |
