Mtengo wa AN451
KUKHALITSA NTCHITO ZA SOFTWARE YA M-BASI YOSANGALALA

Mawu Oyamba

Cholembachi chikufotokoza za kukhazikitsidwa kwa Silicon Labs kwa Wireless M-Bus pogwiritsa ntchito Silicon Labs C8051 MCU ndi EZRadioPRO®. Wireless M-bus ndi European Standard yowerengera mita pogwiritsa ntchito 868 MHz frequency band.

Zigawo za Stack

Wireless M-Bus amagwiritsa ntchito mtundu wa 3-wosanjikiza wa IEC, womwe ndi gawo la 7-wosanjikiza OSI model (onani Chithunzi 1).

The Physical layer (PHY) imatanthauzidwa mu EN 13757-4. Zosanjikiza zakuthupi zimatanthauzira momwe ma bits amasinthidwira ndikufalitsidwa, mawonekedwe a modemu ya RF (chiwerengero cha chip, mawu oyambira, ndi mawu olumikizana), ndi magawo a RF (kusinthasintha, ma frequency apakati, ndi kupatuka pafupipafupi).
Gawo la PHY limayendetsedwa pogwiritsa ntchito kuphatikiza kwa hardware ndi firmware. EZRadioPRO imagwira ntchito zonse za RF ndi modemu. EZRadioPRO imagwiritsidwa ntchito mumayendedwe a FIFO ndi chogwirira paketi. Module ya MbusPhy.c imapereka mawonekedwe a SPI, encoding/decoding, block read/write, and packet handling and manage the transceiver states.
Chigawo cha ulalo wa M-Bus Data chimakhazikitsidwa mu gawo la MbusLink.c. Mawonekedwe a M-Bus Application Programming ali ndi ntchito zapagulu zomwe zitha kuyitanidwa kuchokera pagawo la pulogalamu mu ulusi waukulu. Module ya MbusLink imagwiritsanso ntchito Data Link Layer. Chigawo cha ulalo wa Data chidzapanga ndi kukopera deta kuchokera ku buffer ya TX kupita ku buffer ya MbusPhy TX, ndikuwonjezera mitu yofunikira ndi CRCs.
Chigawo cha Application sichili gawo la firmware ya M-bus. Ntchito yosanjikiza imatanthawuza momwe mitundu yambiri ya data iyenera kusinthidwa kuti itumizidwe. Mamita ambiri amangofunika kutumiza mtundu umodzi kapena iwiri ya data. Kuonjezera nambala yochuluka kuti mutengere mtundu uliwonse wa deta ku mita kungawonjezere nambala yosafunika ndi mtengo ku mita. Zingakhale zotheka kukhazikitsa laibulale kapena mutu file ndi mndandanda wokwanira wa mitundu ya data. Komabe, makasitomala ambiri a metering amadziwa ndendende mtundu wa data womwe angafunikire kuti atumize ndipo atha kunena za mulingo wofotokozera zambiri. Wowerenga waponseponse kapena wosuta atha kugwiritsa ntchito mitundu yonse yamitundu yogwiritsira ntchito pa PC GUI. Pazifukwa izi, ntchito yosanjikiza imagwiritsidwa ntchito pogwiritsa ntchito example mapulogalamu a mita ndi owerenga.

Miyezo Yofunika

1. EN 13757-4
   EN 13757-4
   Njira yolumikizirana yamamita ndi kuwerenga kwakutali kwamamita
   Gawo 4: Kuwerengera mita opanda zingwe
   Kuwerengera kwa radiometer kuti igwire ntchito mu gulu la 868 MHz mpaka 870 MHz SRD
2. EN 13757-3
   Njira yolumikizirana yamamita ndi kuwerenga kwakutali kwamamita
   Gawo 3: Ntchito yodzipereka yosanja
3. IEC 60870-2-1: 1992
   Telecontrol zida ndi machitidwe
   Gawo 5: Njira zotumizira
   Gawo 1: Njira yotumizira ulalo
4. IEC 60870-1-1: 1990
   Telecontrol zida ndi machitidwe
   Gawo 5: Njira zotumizira
   Gawo 1: Mawonekedwe azithunzi zotumizira

Matanthauzo

• M-BasiM-Bus ndi mulingo wama waya wowerengera mita ku Europe.
• Wireless M-Bus-Wireless M-Bus yowerengera mita ku Europe.
• PHY-Physical Layer imatanthawuza momwe ma data bits ndi ma byte amasinthidwira ndikufalitsidwa.
• API—Mawonekedwe a Application Programmer.
• KULUMIKIZANA-Data Link Layer imatanthawuza momwe midadada ndi mafelemu amafatsidwira.
• CRC-Cyclic Redundancy Check.
• FSK-Frequency Shift Keying.
• Chip-Chigawo chaching'ono kwambiri cha data yopatsirana. Dongosolo limodzi la data limasungidwa ngati tchipisi angapo.
• Module-AC kodi source .c file.

M-Bus PHY Functional Description

Kutsatizana Koyamba

Mayendedwe Oyambilira otchulidwa ndi mafotokozedwe a M-basi ndi nambala yophatikizira ziro ndi zina. A imodzi imatanthauzidwa ngati ma frequency apamwamba, ndipo zero amatanthauzidwa ngati ma frequency otsika.
nx (01)
Zosankha zoyambira za Si443x ndi nambala yophatikizika ya ma nibbles okhala ndi zosinthana ndi ziro.
nx (1010)
Chiyambi chokhala ndi chitsogozo chowonjezera sichingakhale vuto, koma, ndiye, mawu olumikizirana ndi malipiro angasokonezedwe ndi pang'ono.
Yankho lake ndikutembenuza paketi yonse poyika injini mu regista ya Modulation Control 2 (0x71). Izi zidzatembenuza mawu oyamba, kulunzanitsa mawu, ndi data ya TX/RX. Zotsatira zake, deta iyenera kusinthidwa polemba data ya TX kapena kuwerenga RX. Komanso, mawu olumikizira amasinthidwa musanalembe ku Si443x Synchronization Word registry.

Kulunzanitsa Mawu

Mawu olumikizana omwe amafunidwa ndi EN-13757-4 mwina ndi ma 18 chips a Mode S ndi Mode R kapena tchipisi 10 a Model T. Mawu olumikizirana a Si443x ndi 1 mpaka 4 mabayiti. Komabe, popeza mawu olumikizirana nthawi zonse amatsogozedwa ndi mawu oyamba, magawo asanu ndi limodzi omaliza a mawu oyambira amatha kuonedwa ngati gawo la mawu olumikizirana; chifukwa chake, liwu loyamba la kulunzanitsa limaphatikizidwa ndi kubwereza katatu kwa ziro kutsatiridwa ndi kumodzi. Mawu olumikizirana amaphatikizidwa musanalembe ku registry ya Si443x.
Table 1. Kulunzanitsa Mawu a Mode S ndi Mode R

EN 13757-4	00	01110110	10010110	binary
	00	76	96	hex
ndi (01) x 3	01010100	01110110	10010110	binary
	54	76	96	hex
wowonjezera	10101011	10001001	01101001	binary
	AB	89	69	hex

Table 2. Kulunzanitsa Mawu a Mode T Meter kupita kwina

SYNCH	SYNCH	SYNCH
MAWU	MAWU	MAWU
3	2	1

Kutalikirana Koyamba

Kuyamba kocheperako kumatchulidwa pamitundu inayi yogwiritsira ntchito. Ndizovomerezeka kukhala ndi mawu oyamba otalikirapo kuposa momwe adafotokozera. Kuchotsa tchipisi zisanu ndi chimodzi pamayambiriro kumapereka chiwerengero chochepa cha tchipisi tambiri ya Si443x. Kukhazikitsa kumawonjezera ma nibbles awiri owonjezera pamawonekedwe onse amfupi oyambira kuti athandizire kuzindikira koyambirira komanso kugwirizanirana. Mawu oyamba pa Mawonekedwe S okhala ndi chiyambi chachitali ndiatali kwambiri; kotero, mawu oyamba ochepa amagwiritsidwa ntchito. Kutalika koyambilira kwa ma nibbles kumalembedwa ku Register ya Preamble Length (0x34). Kaundula wautali woyambira amatsimikizira zoyambira pakupatsira kokha. Mafotokozedwe ocheperako komanso makonzedwe autali woyambira akufotokozedwa mwachidule mu Gulu 3.
Table 3. Kufalitsa Utali Wamayambiriro

	EN-13757-4 osachepera		Si443x Chiyambi Kukhazikitsa		Kulunzanitsa Mawu	Zonse	zowonjezera
	nx (01)	chips	mbaula	chips	chips	chips	chips
Chiyambi chachifupi cha Mode S	15	30	8	32	6	38	8
Kuyamba kwa Mode S	279	558	138	552	6	558	0
Mode T (mita-zina)	19	38	10	40	6	46	8
Njira R	39	78	20	80	6	86	8

Kuyamba kocheperako kolandirira kumatsimikiziridwa ndi Regista ya Preamble Detection Control (0x35). Mukalandira, kuchuluka kwa ma bits mu liwu lolunzanitsa kuyenera kuchotsedwa pachiyambi chodziwika kuti mudziwe mawu oyamba ogwiritsira ntchito. Nthawi yochepa yokhazikika ya wolandirayo ndi 16-chips ngati AFC yayatsidwa kapena 8-chips ngati AFC yayimitsidwa. Nthawi yokhazikitsira wolandila imachotsedwanso pamayambiriro omwe angagwiritsidwe ntchito kuti adziwe malo ochepera a regista ya Preamble Detection Control.

Kuthekera kwa chiyambi chabodza kumatengera kukhazikitsidwa kwa regista ya Preamble Detection Control. Kukhazikitsa kwachidule kwa 8-chips kungapangitse kuti mawu oyambira adziwike pamasekondi angapo aliwonse. Kukonzekera kovomerezeka kwa 20chips kumapangitsa kuzindikira koyambirira kwabodza kukhala chochitika chosayembekezeka. Kutalika koyambilira kwa Mode R ndi Mode SL ndiutali wokwanira kuti makonzedwe ovomerezeka agwiritsidwe ntchito.
Pali phindu lochepa kwambiri popangitsa kuti choyambiriracho chizindikire motalika kuposa tchipisi 20.
AFC ndiyoyimitsidwa kwa Model S yokhala ndi chiyambi chachifupi ndi Model T. Izi zimachepetsa nthawi yokhazikika ya wolandila ndikuloleza kuwonekera kwanthawi yayitali. Ndi AFC yolemala, Mode T imatha kugwiritsa ntchito makonda ovomerezeka a tchipisi 20. Kuyika kwa ma nibbles 4 kapena tchipisi 20 kumagwiritsidwa ntchito pa Model S yokhala ndi mawu oyamba. Izi zimapangitsa kuti mwayi wodziwikiratu zabodza ukhale wapamwamba pang'ono pamtunduwu.
Table 4. Kuzindikira Koyamba

	EN-13757-4 osachepera		Kulunzanitsa Mawu	zogwiritsidwa ntchito chiyambi	Kukhazikika kwa RX	Dziwani min	Si443x Chiyambi Kukhazikitsa Kudziwika
	nx (01)	chips	chips	chips	chips	chips	mbaula	chips
Chiyambi chachifupi cha Mode S	15	30	6	24	8*	16	4	16
Chiyambi chachitali cha Model S	279	558	6	552	16	536	5	20
Model T (mita-zina)	19	38	6	32	8*	24	5	20
Njira R	39	78	6	72	16	56	5	20
*Zindikirani: AFC yayimitsidwa

Wolandirayo amapangidwa kuti azilumikizana ndi chotumizira pogwiritsa ntchito mawu oyamba oyambira. Izi zimawonetsetsa kuti wolandila azilumikizana ndi ma transmitter ogwirizana ndi M-bus.
Kufotokozera kwa Wireless M-Bus kumafuna koyambira kwanthawi yayitali kwa Mode S1 ya tchipisi 558. Izi zidzatenga pafupifupi 17 ms kuti mungotumiza mawu oyamba. Si443x sichifuna kuyambika kwautali wotere ndipo sichimapindula ndi chiyambi chachitali. Ngakhale kuyambika kwautali kumawonedwa ngati kosankha kwa Mode S2, palibe chifukwa chogwiritsa ntchito mawu oyamba ndi Si443x. Ngati mukufuna kulumikizana ndi njira imodzi, Mode T1 ipereka chiwongolero chachifupi, kuchuluka kwa data, komanso moyo wautali wa batri. Ngati kulumikizana kwanjira ziwiri pogwiritsa ntchito Mode S2 kukufunika, mawu oyamba afupiafupi akulimbikitsidwa.
Zindikirani kuti gawo lodziwikiratu la Model S lokhala ndi koyambira lalitali ndilotalikirapo kuposa kuchuluka kwa ma nibbles omwe amaperekedwa ku Model S yokhala ndi mawu oyambira pang'ono. Izi zikutanthauza kuti cholandila cha Mode S choyambira chachitali sichidzazindikira mawu oyambira kuchokera pamawu amfupi oyambira a Mode S. Izi ndizofunikira ngati wolandila wa Mode S woyambira nthawi yayitali adzalandira phindu lililonse pamayambiriro atali.
Zindikirani kuti cholandila chachidule cha Mode S choyambira chidzazindikira zoyambira ndikulandila mapaketi kuchokera pamawonekedwe am'mbuyomu a Mode S.
chopatsira ndi cholumikizira chachitali cha Mode S; kotero, nthawi zambiri, wowerenga mita ayenera kugwiritsa ntchito masinthidwe amfupi oyambira a Mode S.

Encoding/Decoding

Kufotokozera kwa Wireless M-bus kumafuna njira ziwiri zosiyana zolembera. Encoding ya Manchester imagwiritsidwa ntchito pa Mode S ndi Mode R. Encoding ya Manchester imagwiritsidwanso ntchito pa ulalo wa mita ku Model T. Ulalo wa Model T wa mita kupita kwina umagwiritsa ntchito ma encoding 3 mwa 6.
1. Manchester Encoded/Decoding
Kabisidwe ka Manchester ndi kofala m'mbiri yamakina a RF kuti azitha kuchira komanso kutsata wotchi pogwiritsa ntchito modemu yosavuta komanso yotsika mtengo. Komabe, wailesi yamakono yogwira ntchito kwambiri ngati Si443x sifunikira encoding ya Manchester. Ma encoding a Manchester amathandizidwa makamaka kuti agwirizane ndi miyezo yomwe ilipo, koma kuchuluka kwa data kwa Si443x kumachulukitsidwa kawiri osagwiritsa ntchito kabisidwe ka Manchester.
Si443x imathandizira ma encoding a Manchester ndikuwongolera paketi yonse mu hardware. Tsoka ilo, liwu lolumikizana silinasinthidwe ndi Manchester. Kutsatira kolakwika kwa Manchester kudasankhidwa mwadala kuti liwu la kulunzanitsa. Izi zimapangitsa kuti ma encoding a Manchester asagwirizane ndi ma wayilesi ambiri omwe alipo, kuphatikiza Si443x. Zotsatira zake, ma encoding a Manchester ndi decoding ayenera kuchitidwa ndi MCU. Bite iliyonse pa data yosasungidwa imakhala ndi ma data asanu ndi atatu. Pogwiritsa ntchito encoding ya Manchester, pang'onopang'ono deta iliyonse imayikidwa mu chizindikiro cha chip ziwiri. Popeza deta yosungidwa iyenera kulembedwa ku wailesi ya FIFO tchipisi zisanu ndi zitatu panthawi, deta imodzi imasungidwa ndikulembedwa ku FIFO nthawi imodzi.
Table 5. Manchester Encoding

deta	Fufuzani:		0x34 pa		mabayiti
	Fufuzani:	0x2 pa	0x3 pa	0x4 pa	mbaula
	1	10	11	100	binary
chip	10101001	10100110	10100101	10011010	binary
FIFO	OxA9	OxA6	OxA5	Kutumiza	hex

Bite iliyonse yomwe iyenera kutumizidwa imadutsa byte imodzi panthawi imodzi kupita ku encode byte function. Ntchito ya encode byte idzayitana ntchito ya encode nibble kawiri, choyamba kwa nibble yofunikira kwambiri ndiyeno kwa nibble yofunikira kwambiri.
Manchester encoding mu mapulogalamu sikovuta. Kuyambira pachofunikira kwambiri, imodzi imasungidwa ngati "01" chip sequence. Ziro imayikidwa ngati "10" chip sequence. Izi zitha kuchitika mosavuta pogwiritsa ntchito lupu ndikusintha ma bits awiri pachizindikiro chilichonse. Komabe, ndizofulumira kungogwiritsa ntchito tebulo losavuta la 16 lolowera pa nibble iliyonse. Ntchito ya encode ya Manchester nibble imasunga deta ndikuyilembera ku FIFO. Tchipisi amatembenuzidwa asanalembere ku FIFO kuti afotokozere zomwe zasinthidwa.
Mukalandira, byte iliyonse mu FIFO imakhala ndi tchipisi zisanu ndi zitatu ndipo imasinthidwa kukhala nsonga imodzi ya data. Ntchito yowerengera block imawerenga byte imodzi panthawi kuchokera ku FIFO ndikuyitanitsa ntchito ya decode byte. Tchipisi zimatembenuzidwa pambuyo powerenga kuchokera ku FIFO kuwerengera zofunikira zoyambira. Chilichonse cha tchipisi ta Manchester chimasinthidwa kukhala chidziwitso chambiri. Nibble yosinthidwa imalembedwa ku buffer ya RX pogwiritsa ntchito kulemba nibble RX buffer ntchito.
Zindikirani kuti ma encoded ndi decoding amachitidwa ndi data imodzi panthawi imodzi. Kuyika nkhokwe ku buffer kungafune buffer yowonjezera kuwirikiza kawiri kuchuluka kwa data yosasungidwa. Kusindikiza ndi kusindikiza kumathamanga kwambiri kuposa kuchuluka kwa data komwe kumathandizira kwambiri (tchipisi 100 k pamphindikati). Popeza Si443x imathandizira kuwerenga ndi kulemba kwa ma-byte angapo ku FIFO, pali kamutu kakang'ono pakugwiritsa ntchito kuwerenga ndi kulemba kwa single-byte. Kutsogolo kuli pafupifupi 10 µs kwa tchipisi 100 zosungidwa. Ubwino wake ndikusunga RAM kwa 512 byte.
2. Atatu mwa asanu ndi limodzi Kabisidwe Decoding
Njira yokhotakhota Atatu-pa-Sikisi yotchulidwa mu EN-13757-4 ikugwiritsidwanso ntchito mu firmware pa MCU. Encoding iyi imagwiritsidwa ntchito pa liwiro lalikulu (tchipisi 100 k pamphindi) Mode T kuchokera pa mita kupita kwina. Model T imapereka nthawi yayifupi kwambiri yotumizira komanso moyo wautali kwambiri wa batri pamamita opanda zingwe.
Bite iliyonse ya data yomwe iyenera kufalitsidwa imagawidwa mu ma nibbles awiri. Chofunikira kwambiri chimasindikizidwa ndikufalitsidwa poyamba. Apanso, izi zimagwiritsidwa ntchito pogwiritsa ntchito encode byte ntchito yomwe imatcha encode nibble ntchito kawiri.
Dongosolo lililonse la data limayikidwa mu chizindikiro cha chip sikisi. Mndandanda wa zizindikiro zisanu ndi chimodzi ziyenera kulembedwa ku 8chip FIFO.
Pa encoding, ma byte awiri a data amasungidwa ngati ma nibbles anayi. Njoka iliyonse ndi chizindikiro cha 6-chip. Zizindikiro zinayi za 6chip zimaphatikizidwa ngati ma byte atatu.
Table 6. Atatu Mwa asanu ndi limodzi Encoding

deta	0x12 pa			0x34 pa			mabayiti
	Fufuzani:	0x2 pa		0x3 pa		0x4 pa	mbaula
chip	15	16		13		34	octal
	1101	1110		1011		11100	binary
FIFO	110100		11100010		11011100		binary
	0x34 pa		OxE2		OxDC		hex

M'mapulogalamu, ma encoding atatu mwa asanu ndi limodzi akugwiritsidwa ntchito pogwiritsa ntchito zisa zitatu. Ntchito ya encode byte idzayitana ntchito ya encode nibble kawiri. Ntchito ya encode nibble imagwiritsa ntchito tebulo loyang'ana pachizindikiro cha chip zisanu ndi chimodzi ndikulemba chizindikiro ku Shift Three mwa ntchito zisanu ndi chimodzi. Izi zimagwiritsa ntchito kaundula wa 16-chip shift mu software. Chizindikirocho chimalembedwa ku kaundula wocheperako kwambiri wa kaundula wa shift. Kaundula imasinthidwa kumanzere kawiri. Izi zikubwerezedwa katatu. Pamene byte yathunthu ilipo mu kaundula wapamwamba wa kaundula, imatembenuzidwa ndikulembedwa ku FIFO.
Popeza kuti byte iliyonse ya data imasungidwa ngati ma encoded byte imodzi ndi theka, ndikofunikira kuchotsa kaundula wosinthira kuti ma byte oyamba akhale olondola. Ngati kutalika kwa paketi ndi nambala yosamvetseka, mutatha kuyika ma byte onse, padzakhalabe nibble imodzi yotsalira mu kaundula. Izi zimayendetsedwa ndi positi monga tafotokozera m'gawo lotsatira.
Kujambula zitatu mwa zisanu ndi chimodzi zosungidwa ndi njira yosinthira. Mukatsitsa, ma byte atatu osungidwa amasinthidwa kukhala ma data awiri. Regista yosinthira mapulogalamu imagwiritsidwanso ntchito kuphatikizira ma byte a data yomwe yasinthidwa. Gome loyang'ana lolowera 64 limagwiritsidwa ntchito pojambula. Izi zimagwiritsa ntchito zozungulira zochepa koma zokumbukira zambiri. Kusaka tebulo loyang'ana 16-lolowera chizindikiro chofananira kumatenga nthawi yayitali.
Postamble
Ma Wireless M-bus specifications ali ndi zofunikira zenizeni za positi kapena ngolo. Pamitundu yonse, osachepera ndi tchipisi ziwiri, ndipo kuchuluka kwake ndi tchipisi zisanu ndi zitatu. Popeza chigawo chochepa cha atomiki cha FIFO ndi chimodzi, 8-chip trailer imagwiritsidwa ntchito pa Mode S ndi Mode R. The Mode T postamble ndi tchipisi zisanu ndi zitatu ngati kutalika kwa paketi ndi ngakhale kapena tchipisi zinayi ngati paketi kutalika ndi kosamvetseka. Positi yapaketi ya four-chip yautali wa paketi yosamvetseka imakwaniritsa zofunikira zokhala ndi tchipisi zosachepera ziwiri.
Table 7. Kutalika kwa Postamble

	Kutalika kwa Postamble (tchipisi)
	min	max	Kukhazikitsa		mndandanda wa chip
Mode S	2	8	8		1010101
Mode T	2	8	4	(zachilendo)	101
			8	(ngakhale)	1010101
Njira R	2	8	8		1010101

Packet Handler

Chogwirizira paketi pa Si443x chingagwiritsidwe ntchito mumitundu yosiyanasiyana ya paketi m'lifupi kapena mawonekedwe okhazikika a paketi. Kusintha kwa paketi m'lifupi mwake kumafunika kutalika kwa paketi pambuyo pa mawu olumikizirana ndi ma byte amutu osankha. Atalandira, Wailesi idzagwiritsa ntchito kutalika kwa byte kuti idziwe mapeto a paketi yovomerezeka. Pakutumiza, wailesi imayika gawo lalitali pambuyo pa ma byte amutu.
Munda wa L wa protocol ya M-bus yopanda zingwe sungagwiritsidwe ntchito pagawo la Si443x kutalika. Choyamba, gawo la L silo kutalika kwa paketi. Ndi chiwerengero cha ma byte owonjezera omwe amalipidwa osaphatikiza ma byte a CRC kapena encoding. Kachiwiri, L -field palokha imasungidwa pogwiritsa ntchito encoding ya Manchester kapena Three out of Six encoding for Mode T mita kupita kwina.
Kukhazikitsa kumagwiritsa ntchito chogwirira paketi mumayendedwe okhazikika a paketi m'lifupi mwake potumiza ndi kulandira. Mukatumiza, gawo la PHY liwerenga gawo la L mu buffer yotumizira ndikuwerengera kuchuluka kwa ma encoded byte, kuphatikiza positi. Chiwerengero chonse cha ma encoded byte oti atumizidwe amalembedwa ku Packet Length Register (0x3E).
Mukalandira, ma byte awiri oyambilira amasinthidwa, ndipo gawo la L limalembedwa ku buffer yolandila. Malo a L amagwiritsidwa ntchito kuwerengera kuchuluka kwa ma encoded byte kuti alandire. Chiwerengero cha ma byte osungidwa omwe alandilidwe amalembedwa ku Packet Length Register (0x3E). Positiyo imatayidwa.
MCU iyenera kufotokozera gawo la L, kuwerengera kuchuluka kwa ma byte osungidwa, ndikulemba mtengo ku regista ya Packet Length kutalika kwa paketi kwakanthawi kochepa kusanalandire. Malo amfupi kwambiri ovomerezeka a L pagawo la PHY ndi 9, opatsa ma byte 12 osasindikizidwa. Izi zimapereka ma byte 18 a Model T. Ma byte awiri oyamba adasinthidwa kale. Chifukwa chake, kaundula wa Utali wa paketi uyenera kusinthidwa nthawi za 16-byte pa 100 kbps kapena 1.28 milliseconds. Ili si vuto kwa 8051 yomwe ikuyenda pa 20 MIP.
Chiwerengero cha ma byte oti alandire sichimaphatikizirapo positi, kusiyapo ma positi a ma chip anayi omwe amagwiritsidwa ntchito pamapaketi a Mode T okhala ndi paketi yosamvetseka. Chifukwa chake, wolandila safuna positi, kupatula mapaketi autali a Model T odd. Positiyi ikufunika kuti mupereke chiwerengero chokwanira cha ma byte osungidwa. Zomwe zili mu postamble zimanyalanyazidwa; kotero, ngati positi sipatsirana, chipwirikiti cha phokoso chidzalandiridwa ndikunyalanyazidwa. Popeza kuchuluka kwa ma byte osungidwa kumangokhala 255 (0xFF), kukhazikitsa kumachepetsa gawo lalikulu la L pamitundu yosiyanasiyana.
Table 8. Paketi Kukula Malire

	encod		decoded		M-basi
	mabayiti		mabayiti		Munda wa L
	Dec	hex	Dec	hex	Dec	hex
Mode S	255	FF	127	7 F	110	6E
Mode T (mita-zina)	255	FF	169	A9	148	94
Njira R	255	FF	127	7 F	110	6E

Malire awa nthawi zambiri amakhala apamwamba kuposa momwe amagwiritsidwira ntchito pamamita opanda zingwe. Kutalika kwa paketi kuyenera kukhala kochepa kuti mukhale ndi moyo wabwino wa batri.
Kuphatikiza apo, wogwiritsa ntchitoyo atha kutchula gawo lalikulu la L lomwe liyenera kulandiridwa (USER_RX_MAX_L_FIELD). Izi zimatsimikizira kukula kofunikira kwa buffer yolandirira (USER_RX_BUFFER_SIZE).
Kuthandizira malo opambana a L a 255 kungafune cholandirira mabayiti 290 ndi ma byte opitilira 581 a Manchester. Wothandizira paketi angafunike kuyimitsidwa ndipo kaundula wa Packet Length singagwiritsidwe ntchito pamenepo. Izi ndizotheka, koma ndizosavuta kugwiritsa ntchito chogwirira paketi, ngati kuli kotheka.

Kugwiritsa ntchito FIFO

Si4431 imapereka 64 byte FIFO yotumiza ndi kulandira. Popeza kuchuluka kwa ma encoded byte ndi 255, paketi yonse yosungidwa mwina singakwane mu buffer ya 64-byte.
Kutumiza
Potumiza, chiwerengero chonse cha ma encoded byte chimawerengedwa. Ngati chiwerengero chonse cha ma encoded byte, kuphatikizapo positi, ndi ochepera 64 byte, paketi yonseyo imalembedwa ku FIFO ndipo paketi yokhayo yomwe yatumizidwa imasokoneza. Mapaketi afupiafupi ambiri adzatumizidwa mumsewu umodzi wa FIFO.
Ngati chiwerengero cha ma byte osungidwa chikuposa 64, kusamutsidwa kangapo kwa FIFO kudzafunika kutumiza paketi. Ma byte 64 oyamba adalembedwa ku FIFO. Paketi Yotumizidwa ndi TX FIFO Zosokoneza Zopanda kanthu zimayatsidwa. The TX FIFO Almost Empty threshold is set to 16 bytes (25%). Pa chochitika chilichonse cha IRQ, kaundula wa 2 amawerengedwa. Packet Sent bit imafufuzidwa poyamba, ndipo, ngati paketiyo siinatumizidwe kwathunthu, ma byte 48 otsatirawa a data encoded amalembedwa ku FIFO. Izi zimapitilira mpaka ma byte onse osungidwa alembedwa ndipo kusokoneza kwa Packet Sent kumachitika.
1. Kulandila
Pakulandira, poyambirira, kusokoneza kwa Sync Word kokha ndikoyambitsidwa. Mukalandira mawu olumikizirana, kusokoneza kwa mawu kumayimitsidwa ndipo FIFO Almost Full interrupt imayatsidwa. FIFO pafupifupi malire onse ayamba kukhala 2 mabayiti. Kusokoneza koyamba kwa FIFO Almost Full kumagwiritsidwa ntchito kudziwa pamene ma byte awiri alandilidwa. Utali utalandiridwa, utaliwo umasankhidwa ndipo kuchuluka kwa ma encoded byte kumawerengedwa. The RX FIFO pafupifupi malire a Full ndiye amayikidwa ku 48 byte. RX FIFO yatsala pang'ono kudzaza ndipo kusokoneza Paketi Yovomerezeka kumayatsidwa. Pa chochitika chotsatira cha IRQ, kaundula wa 1 amawerengedwa. Choyamba, Paketi Yovomerezeka Paketi imafufuzidwa, ndiyeno FIFO Pafupifupi Yonse Yonse imafufuzidwa. Ngati RX FIFO Almost Full bit yakhazikitsidwa, ma byte 48 otsatirawa amawerengedwa kuchokera ku FIFO. Ngati paketi yoyenera yayikidwa, yotsalira paketiyo imawerengedwa kuchokera ku FIFO. MCU imasunga kuchuluka kwa ma byte omwe adawerengedwa ndikusiya kuwerenga pambuyo pa byte yomaliza.

Gulu Loyanjanitsa

Dongosolo la ulalo wa data limagwiritsa ntchito 13757-4:2005 yogwirizana ndi ulalo. Data link layer (LINK) imapereka kulumikizana pakati pa physical layer (PHY) ndi application layer (AL).
Data Link Layer imagwira ntchito izi:

• Amapereka ntchito zomwe zimasamutsa deta pakati pa PHY ndi AL
• Amapanga ma CRC a mauthenga otuluka
• Imazindikira zolakwika za CRC pamawu obwera
• Amapereka maadiresi enieni
• Imavomereza kusamutsidwa kwamitundu iwiri yolumikizirana
• Mafelemu a data bits
• Imazindikira zolakwika pakupanga mauthenga obwera

Link Layer Frame Format

Mtundu Wopanda Waya wa M-Bus womwe umagwiritsidwa ntchito mu EN 13757-4:2005 wachokera ku FT3 (Mtundu wa 3) wa chimango kuchokera ku IEC60870-5-2. Fungoli lili ndi midadada imodzi kapena zingapo za data. Chida chilichonse chili ndi gawo la 16-bit CRC. Bock yoyamba ndi chipika chokhazikika cha 12 byte chomwe chimaphatikizapo L-field, C-field, M-field, ndi A-Field.

1. Munda wa L
   The L-field ndi kutalika kwa Link layer data payload. Izi sizikuphatikiza L-munda womwewo kapena ma byte aliwonse a CRC. Zimaphatikizapo L-field, C-field, M-field, ndi A-Field. Izi ndi gawo la malipiro a PHY.
   Chifukwa kuchuluka kwa ma encoded byte kumangokhala 255 byte, mtengo wokwanira wothandizidwa ndi M-field ndi 110 byte pa Manchester encoded data ndi 148 byte pa Mode T Three-Out-Six data encoded.
   Chigawo cha Link chili ndi udindo wowerengera gawo la L pakutumiza. Ulalo-wosanjikiza udzagwiritsa ntchito L-munda polandila.
   Dziwani kuti gawo la L silikuwonetsa kutalika kwa malipiro a PHY kapena kuchuluka kwa ma byte osungidwa. Mukatumiza, PHY idzawerengera kutalika kwa PHY ndi kuchuluka kwa ma byte osungidwa. Mukalandira, PHY idzasankha malo a L ndikuwerengera kuchuluka kwa ma byte kuti adziwe.
2. C-Munda
   C-munda ndi gawo lowongolera chimango. Gawoli limazindikiritsa mtundu wa chimango ndipo limagwiritsidwa ntchito pamiyambi yosinthira ulalo wa data. C-munda ikuwonetsa mtundu wa chimango - TUMA, TULANI, PEMBANI, kapena YANKHANI. Pankhani ya mafelemu a SEND ndi REQUEST, gawo la C likuwonetsa ngati CONFIRM kapena RESPOND akuyembekezeka.
   Mukamagwiritsa ntchito ntchito ya Link TX, mtengo uliwonse wa C ungagwiritsidwe ntchito. Mukamagwiritsa ntchito Link Service Primitives, gawo la C limakhala lokhalokha malinga ndi EN 13757-4:2005.
3. M-Munda
   The M-field ndi code ya opanga. Opanga atha kupempha khodi ya zilembo zitatu kuchokera ku zotsatirazi web adilesi: http://www.dlms.com/flag/INDEX.HTM Chikhalidwe chilichonse cha zilembo zitatu chimasungidwa ngati ma bits asanu. Khodi ya 5-bit ingapezeke potenga khodi ya ASCII ndikuchotsa 0x40 ("A"). Ma code atatu a 5-bit amalumikizidwa kuti apange 15-bits. Chofunikira kwambiri ndi zero.
4. A-Munda
   Gawo la ma adilesi ndi adilesi yapadera ya 6-byte pa chipangizo chilichonse. Adilesi yapadera iyenera kuperekedwa ndi wopanga. Ndi udindo wa wopanga aliyense kuonetsetsa kuti chipangizo chilichonse chili ndi adilesi yapadera ya 6-byte. Adilesi ya Send and Request frames ndi adilesi yanu ya mita kapena chipangizo china. Mafelemu otsimikizira ndi mayankho amatumizidwa pogwiritsa ntchito adilesi ya chipangizocho.
5. CI-Field
   The CI-field ndiye mutu wa ntchito ndipo imatchula mtundu wa data yomwe ili muzolipira za data. Pomwe EN13757-4:2005 imatchula zamtengo wapatali, Link Service Primitives imalola kuti mtengo uliwonse ugwiritsidwe ntchito.
6. Mtengo CRC
   CRC imatchulidwa mu EN13757-4:2005.
   CRC Polynomial ndi:
   X16 + x13 + x12 + x11 + x10 + x8 +x6 + x5 +x2 + 1
   Dziwani kuti M-Bus CRC imawerengedwa pa block iliyonse ya 16-byte. Zotsatira zake ndikuti ma byte 16 aliwonse amafunikira ma byte 18 kuti atumizidwe,

Zina Zowonjezera

Kuti mumve zambiri za Kukhazikitsa kwa Link Layer, onani "AN452: Wireless M-Bus Stack Programmers Guide".

Kuwongolera Mphamvu

Chithunzi 2 chikuwonetsa nthawi yoyang'anira mphamvu ya mitaamppogwiritsa ntchito Mode T1.

MCU iyenera kukhala yogona nthawi zonse kuti isunge mphamvu. Mu exampndi, MCU ikugona pamene RTC ikuyenda, podikirira pawailesi yoyambira, komanso potumiza kuchokera ku FIFO. MCU idzadzuka kuchokera ku chizindikiro cha EZRadioPRO IRQ cholumikizidwa ndi kudzutsidwa kwa Port Match.
Mukatumiza mauthenga otalika kuposa chipika chimodzi, MCU iyenera kudzuka kuti mudzaze FIFO (kutengera FIFO pafupifupi kusokoneza kopanda kanthu) ndikubwerera kukagona.
MCU iyenera kukhala mu Idle mode yothamanga kuchokera ku oscillator otsika kapena oscillator wophulika powerenga kuchokera ku ADC. ADC imafuna wotchi ya SAR.
Ikapanda kugwiritsidwa ntchito, EZRadioPRO iyenera kukhala mu Shutdown mode yokhala ndi pini ya SDN yoyendetsedwa pamwamba. Izi zimafuna kulumikizana kolimba ndi MCU. Zolembera za EZ Radio Pro sizimasungidwa munjira yotseka; kotero, EZRadioPro imayambitsidwa pa nthawi iliyonse ya RTC. Kuyambitsa Wailesi kumatenga zosakwana 100 µs ndikusunga 400 nA. Izi zimabweretsa kupulumutsa mphamvu kwa 10 µJ, kutengera nthawi ya 10-sekondi.
EZRadioPRO crystal imatenga pafupifupi 16 ms kwa POR. Izi ndizotalika kokwanira kuwerengera CRC pafupifupi midadada isanu ndi itatu. MCU ibwerera kukagona ngati itamaliza ma CRC onse kristalo isanakhazikike. Ngati kubisa kumafunika, nawonso akhoza kuyambitsidwa podikirira pa crystal oscillator.
MCU iyenera kuthamanga pa 20 MHz pogwiritsa ntchito oscillator yotsika mphamvu pa ntchito zambiri. Ntchito zomwe zimafunikira nthawi yodulira nthawi yolondola ziyenera kugwiritsa ntchito chowongolera cholondola komanso chopanda pake m'malo mogona. RTC imapereka chigamulo chokwanira pa ntchito zambiri. Nthawi yoyendetsera mphamvu ya T2 mita exampkugwiritsa ntchito kukuwonetsedwa mu Chithunzi 3.

Kukhazikitsa kwa transceiver kuyenera kukonzedwa bwino ngati mita yadzuka ndipo palibe wowerenga. Nthawi yocheperako / yochulukirapo ya ACK ndi yayitali mokwanira kotero kuti ndizotheka kugwiritsa ntchito C8051F930 RTC ndikuyika MCU munjira yogona.
Zosankha zomanga zimaperekedwa kwa mains kapena owerenga oyendetsedwa ndi USB omwe safunikira kugwiritsa ntchito njira yogona. Njira yopanda ntchito idzagwiritsidwa ntchito m'malo mogona kuti USB ndi UART zisokoneze MCU.

Situdiyo Yosavuta
Dinani kumodzi kulowa kwa MCU ndi zida zopanda zingwe, zolemba, mapulogalamu, malaibulale a code source & zina. Likupezeka pa Windows,
Mac ndi Linux!

IoT Portfolio www.silabs.com/IoT	SW/HW www.silabs.com/simplicity	Ubwino www.silabs.com/quality	Thandizo ndi Community community.silabs.com

Chodzikanira
Silicon Labs ikufuna kupatsa makasitomala zolembedwa zaposachedwa, zolondola, komanso zakuya za zotumphukira zonse ndi ma module omwe amapezeka kwa ogwiritsa ntchito makina ndi mapulogalamu omwe amagwiritsa ntchito kapena akufuna kugwiritsa ntchito zinthu za Silicon Labs. Deta yodziwika bwino, ma module ndi zotumphukira zomwe zilipo, kukula kwa kukumbukira ndi ma adilesi okumbukira zimatanthawuza ku chipangizo chilichonse, ndipo "Zomwe zimaperekedwa" zimatha kusiyanasiyana m'magwiritsidwe osiyanasiyana. Ntchito exampzomwe zalongosoledwa apa ndi zongowonetsera chabe. Silicon Labs ili ndi ufulu wosintha popanda kudziwitsanso zambiri komanso malire pazambiri zamalonda, mawonekedwe, ndi mafotokozedwe apa, ndipo sapereka zitsimikizo zakulondola kapena kukwanira kwa zomwe zaphatikizidwazo. Silicon Labs sadzakhala ndi mlandu pazotsatira zakugwiritsa ntchito zomwe zaperekedwa pano. Chikalatachi sichikutanthauza kapena kufotokoza zilolezo za kukopera zomwe zaperekedwa pansipa kuti apange kapena kupanga mabwalo aliwonse ophatikizika. Zogulitsazo sizinapangidwe kapena kuloledwa kugwiritsidwa ntchito mkati mwa Life Support System popanda chilolezo cholembedwa cha Silicon Labs. "Life Support System" ndi chinthu chilichonse kapena dongosolo lililonse lothandizira kapena kuthandizira moyo ndi / kapena thanzi, zomwe, ngati zitalephera, zikhoza kuyembekezera kuvulaza kwambiri kapena imfa. Zogulitsa za Silicon Labs sizinapangidwe kapena kuloledwa kugwiritsa ntchito zankhondo. Zogulitsa za Silicon Labs sizidzagwiritsidwa ntchito mu zida zowononga kwambiri kuphatikiza (koma osati) zida za nyukiliya, biological, kapena mankhwala, kapena zida zoponya zomwe zimatha kutumiza zida zotere.
Chidziwitso cha Chizindikiro
Silicon Laboratories Inc.®, Silicon Laboratories®, Silicon Labs®, SiLabs®, ndi Silicon Labs logo®, Bluegiga®, Bluegiga Logo®, Clockbuilder®, CMEMS®, DSPLL®, EFM®, EFM32®, EFR, Ember® , Energy Micro, logo ya Energy Micro ndi zophatikizira zake, "ma microcontrollers ochezeka kwambiri padziko lonse lapansi", Ember®, EZLink®, EZRadio®, EZRadioPRO®, Gecko®, ISOmodem®, Precision32®, ProSLIC®, Simplicity Studio®, SiPHY® , Telegesis, the Telegesis Logo®, USBXpress®, ndi zina ndi zizindikiro kapena zizindikiro zolembetsedwa za Silicon Labs. ARM, CORTEX, Cortex-M3, ndi zala zazikulu ndi zizindikiro kapena zizindikilo zolembetsedwa za ARM Holdings. Keil ndi chizindikiro cholembetsedwa cha ARM Limited. Zina zonse kapena mayina amtundu omwe atchulidwa pano ndi zilembo za omwe ali nawo.

Malingaliro a kampani Silicon Laboratories Inc.
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USA
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Zolemba / Zothandizira

SILICON LABS Wireless M-BUS Software Implementation AN451 [pdf] Buku Logwiritsa Ntchito SILICON LABS, C8051, MCU, ndi, EZRadioPRO, Wireless M-bus, Wireless, M-BUS, Software, Implementation, AN451

Maumboni

• Buku Logwiritsa Ntchito