TRANG CH GII THIU DIN N HC & LM SHOWROOM - AUTOMATION LIN H DANH B DOANH NGHIP

Trang ch CNTT vi TH CNTT vi TH Mt s nt khi qut v chun Zigbee

Mt s nt khi qut v chun Zigbee

>>Bi c Thng (Vin NC in t - Tin hc - T ng Ha)

Chng ta tng bit n cc chun giao tip khng dy kh ph bin nh :Wimax, 3G, Bluetooth...Trong nhngnm gn y xut hin mt chun giao tip mi c ng dng rt rng ri trong nhiu lnh vc, l chunZigbee. Bi bo sau s gii thiu nhng nt khi qut nht v chun giao tip ang rt c quan tm ny.

1. Tng quan.Zigbee l mt giao thc c xy dng theo chun IEEE 802.15.4. Giao thc ny c to ra nhm phc v chonhng ng dng yu cu gi thnh v cng sut thp nhng phi c kh nng linh ng trong phm vi rng. ChunZigbee c pht trin v xc tin bi hng Zigbee Alliance, vi s h tr t hn 200 cng ty trn th gii nh:SIEMENS, ATMEL, NI, NEC, TEXAS INSTRUMENTS, EPSON....V bn cht Zigbee cng mt chun giao tip khng dy nh nhng chun khng dy khc : UWB, Wi-Fi, IrDA, 3G,Bluetooth...nhng n mang nhng c tnh k thut v c tnh vt l ring v do s ch ph hp vi mt mngng dng nht nh.

Hnh 1 - Cc ng dng khng dy

Theo nh hnh trn c th thy rng chun Zigbee c c im l phm vi hot ng hp, tc truyn Zigbeethch hp cho cc sensor khng dy v chuyn dng cho cc ng dng gim st, iu khin.

2. u im v nhc im ca Zigbee.

thy c u im v nhc im ca giao thc Zigbee c th theo di bng di y:

u im Nhc im

* Gi thnh thp

* Tiu th cng sut nh

* Kin trc mng linh hot

* c h tr bi nhiu cng ty

* S lng cc nt ln (65k)

* Li mt im chnh c th

gy li h thng.

* Tc truyn thp

* Cha c y cc thit b

pht trin

cho r rng hn, ta hy lm mt php so snh gia chun Zigbee v mt chun khng dy cng kh ph binkhc :

Chun Bluetooth.

c tnh Zigbee Bluetooth

Tiu th cng sut 10mA 100mA

Ca t ng

Cng t ng

Tin tc & S kin

Cng ngh & ng dng

CNTT vi TH

Doanh nhip & Sn phm

Th gii cm bin

TH dn dng

Robot & Robotics

Nghin cu Khoa hc

Sinh vin & Tui tr

Tp ch vi bn c

Vn ngh

Hi p

Tuyn dng ngnh TH

Ca - Cng t ng

Nh ti tr

S kin

Lin kt & Qung co

Tm kim

tm kim... Tm

Qung co&Lin kt

Mi cp nht

TH NM, 27 THNG 8 2009 23:28

Mt s nt khi qut v chun Zigbee | T ng ha file:///C:/Users/HP/Desktop/project 2/Mt s nt khi qut v chun Zigbe...

1 trong 4 02/03/2014 5:46 PM

C th thy rng vi nhng ng dng cho nhiu phn t, yu cu linh hot cao, gi thnh thp, tiu th cngsut nh th dng chun Zigbee l rt ph hp.

3. Di tn Zigbee.

Tn hiu truyn trong giao thc Zigbee thc cht l tn hiu radio. Zigbee c h tr trong cc di tn s sau:

Hnh 2 - Di tn Zigbee

Di 868,3 Mhz: Ch mt knh tn hiu .Trong di ny tc truyn l 20kb/s.

Di 902 Mhz - 928 Mhz: C 10 knh tn hiu t 1 - 10 vi tc truyn thng l 40kb/s.

Di 2,4 Ghz - 2,835 Ghz: c 16 knh tn hiu t 11 - 26 vi tc truyn 250 kb/s.

Trong nhiu ng dng, ngi ta hay dng giao thc Zigbee di tn 2,4 Ghz - 2,835 Ghz. y l di tn ph binv c h tr bi nhiu thit b. Hn na vi Zigbee, di tn ny c ti 16 knh tn hiu trong di (mi knh cchnhau 5MHz tn s) vi tc truyn ln nht: 250kb/s.

4. Kin trc Zigbee.

Cng ging nh trong truyn thng cng nghip, khi thc hin mt giao thc truyn thng, ngi ta thng phida trn mt m hnh kin trc chun. Bt k mt giao thc truyn thng no u c th qui chiu ti mt lp no trong m hnh ca kin trc tng ng. Trong truyn thng cng nghip ta bit n l m hnh qui chiuOSI 7 lp.

Trong giao thc Zigbee, ngi ta cng nh ngha mt kin trc giao tip, l kin trc Zigbee. C th hiu kintrc ny cng tng t nh kin trc OSI 7 lp trong truyn thng cng nghip, xem hnh di.

Hnh 3 - Kin trc OSI v kin trc Zigbee

Ta s i xem xt c th hn v kin trc Zigbee:

Hnh 4 - Kin trc lp (hay ngn xp - Stack)

trong kin trc Zigbee

Zigbee c xy dng trn ca hai lp MAC ( Medium Access Control) v lp vt l PHY. Lp MAC v lp PHYc nh ngha theo chun IEEE 802.15.4 dnh cho cc ng dng WPAN tc thp. c tnh k thut Zigbeesau thm vo 4 lp chnh: lp mng, lp ng dng, lp cc i tng thit b Zigbee ( ZDO) v lp cc itng ngi dng cho php ty bin, linh ng trong chun .

Bn cnh vic tch hp thm hai lp mc cao hn trn cc lp nn, mt s tch hp rt quan trng na l thm vo

H tr online

H tr Web

Mr Phng: 0988906030

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Mt s nt khi qut v chun Zigbee | T ng ha file:///C:/Users/HP/Desktop/project 2/Mt s nt khi qut v chun Zigbe...

2 trong 4 02/03/2014 5:46 PM

cc ZDO ( Zigbee Device Object). Cc ZDO chu trch nhim cho nhiu tc v, trong bao gm: nh ngha vaitr ca cc thit b, t chc v yu cu truy nhp vo mng, bo mt cho thit b...

5. M hnh mng Zigbee

Trong truyn thng dng giao thc Zigbee thng h tr 3 m hnh mng chnh: mng hnh sao, mng hnh cy vmng s li.

Trong lp mng Zigbee cho php 3 kiu thit b:

Zigbee Coordinator (ZC):

Hnh 5: Cc m hnh mng Zigbee

Ch c duy nht 1 ZC trong bt k mng Zigbee no v n c chc nng chnh l kch hot thng tin v mng thngqua cu hnh cc knh, PAN ID v hin trng ngn xp.

Zigbee Router (ZR): L mt thnh phn ca h thng mng m chc nng ca n l thc hin vic vn chuyncc gi tin trong mng. N thc hin cc bng kt ni cng nh nh v a ch cho cc ZED ca n.

Zigbee End Device (ZED): L mt thnh phn ca h thng mng nhng khng tham gia vo qu trnh vn chuyntin. N c c ti u sao cho cng sut tiu th l nh nht nh cc ch bt tn hiu v k thut "sleep".

Qu trnh thit lp trong mt mng Zigbee nh sau:

Qut mng (Network Scan): Cc thit b trong mng s qut cc knh tn hiu, v d nu dng di tn 2,4GHz ths c 16 knh qut, sau thit b s chn knh ph hp nht giao tip trong mng. Ta gi l s chimch : ocupacy.

- Thit lp/Gia nhp mng: Thit b c th to ra mt mng trn mt knh hoc gia nhp vo mt mng tn tisn.

- Pht hin thit b: Thit b s yu cu mng pht hin ra a ch ca mnh trn cc knh c kch hot.

- Pht hin dch v: Thit b qut cc dch v c h tr trn thit b trong phm vi mng.

- Lin kt: Thit b giao tip vi nhau thng qua cc lnh v cc tin nhn iu khin.

6. Cc ng dng ca chun Zigbee.

Nh ni trn: Chun Zigbee rt ph hp vi nhng ng dng yu cu gi thnh thp, tiu th nng lng nhv tnh linh ng tt. V vy ngy nay Zigbee c dng vo rt nhiu ng dng trong cuc sng nh: Cc h chiusng thng minh, HVAC, Cng nghip, Sensor khng dy, bnh vin....C th thy trn hnh di:

Hin nay c rt nhiu hng sn xut v bn cc IC cng nh cc Module h tr truyn nhn bng Zigbee. C thgii thiu mt s sn phm ang c dng rng ri:

Hnh 6: Cc ng dng ca mng Zigbee

MC13202 ca Freescale MRF24J40 ca MICROCHIP

Mt s nt khi qut v chun Zigbee | T ng ha file:///C:/Users/HP/Desktop/project 2/Mt s nt khi qut v chun Zigbe...

3 trong 4 02/03/2014 5:46 PM

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CC2400 ca Texas Instrumen Kt ZAXM-201 ca NEC

KT LUN

Zigbee l mt chun giao tip cn kh mi v cha c s dng nhiu Vit Nam. Tuy nhin trn th gii chunny ang c quan tm v pht trin rt mnh m. D bo trong nhng nm ti cc chp h tr chun ny stng t bin. Ta nn nghin cu v tm hiu dn v cng ngh mi ny!!!

(TCTH Thng 8-2008)

Tin mi hn:

09/10/2009 10:11 - Chp x l, iu khin nhng Cu trc v Phn loi21/09/2009 01:32 - Th trng thit b khng dy trong lnh vc t ng ho nh my21/09/2009 01:28 - T chc truyn thng HART gii thiu giao thc truyn thng Wirelessharttm21/09/2009 01:16 - Gii php qun l mi trng ca phng my ch20/09/2009 00:14 - Cc cng c trn nn Ethernet19/09/2009 14:52 - Nn sn xut ca tng lai K cui17/09/2009 12:17 - ENTERTRON gii thiu Card giao tip MAC17/09/2009 12:11 - ATMEL v IAR SYSTEM phi hp pht trin cng c phn mm cho vi iukhin AT91SAM17/09/2009 12:06 - B chuyn i DC/DC XCSA ca ASI17/09/2009 11:53 - Nn sn xut ca tng lai