I 1.1 v J \)v \J b) Tdn s(f
va cau true.
IEEES02.1 (B) Quan Ii dia chi. m(;lng may tfnh & m;;mg internet. IEEES02.2 IEEES02.3 IEEE802.4 IEEE802.5 IEEES02.6 IEEES02.7 IEEES02.S
Tieu chujn m;:tng cl,lc bO d~mh cho cac dieu khien lien kct
logic. thl!c hi¢n chUc nang lap ket n6i dCr li~u clla OSL
PhllC1I1g phap t6 chuc tham nMp nhicu moi bang cam nMn song m~ng c6 do xung d¢t (CSMA/CD) va d~c tinh lap V?t If.
PhUC1I1g phap truy c~p m~ng buyt truyen rna thong bao va cac
d?c tinh cua lap v~t If.
PhllC1I1g phap truy c~p yang truy~n rna thong baa va cac d~c
tinh clla lap v~t.
Ticu chuan m~ng trung tam. Tieu chuan m;:tng CI,1C bo diii f(lng. Tieu chuan cap quang.
2.5.3.2 Ml)t so giao thuc dlJ(1c sit dl,lug trong cong nghi~p
Co mot s6 tieu chu&n dl.!a tren m6 hlnh lap OSI thllo-ng ullqc su dl,1ng. Hang
General Motor phit trien giao th/fc (if J<Jng che't(lo (ManuJacturing Automation
Protocol-MAP) cho cac ang dl,1ng tl.! dong trang cong xuemg. Tieu chuan nay
dllqc chap nh~n n)ng rai trong cong nghi¢p san xuat. Slf il.!D chQn cac giao thac l<,ti cac 16'p khac nhau phan anh yeu d.u doi vai h~ thong M hqp v6i. moi trllCm.g san xuat. Lap I va 2 dllqc thlfc hi~n trong philn cLing di~n tU. lap 3 va 7 dung cho phan memo Truycn bang dili r(mg duqc Slr dl,1ng cha lap v~t Ii thea tieu
chutln IEEE S02.4. Phuang phap truyen bang diii rong cho phep h~ thong dllqc
Slt dl,\.ng cho nhl1n.g dich vI,\. ngaai nhl1n.g lap yeu cau truyen thong MAP. H~
thong rna thong baa vaj m<;lng buyr duqc sii dl,lllg cho lap ket noi dCr li~u thea lieu chu<ln IEEES02.4 v&i bo dieu khien n6i logic (logical link cantrol-LCL) M
IEEE 802.2 cap 1. Doi vai cac lap khac co the su d~ng tieu churin ISO. T<:ti lap 7, MAP gam cd. djch V1J. thong bao san xuat (manufacturing message service- MMS). m9t Cmg d~ng dang k~ ve truyen th6ng tren m~t bang san xuat (factory floor communication), no xac d~nh cac ho~t d9ng giao ket giua cac b9 dieu
khi8n J~p trlnh (PLC) va may dicu khi~n so ho~e nguoi may. Hlnh 2.77 minh
h9a mQt m~ng MAP.
Ciao tMlc Wlll phong va ky
thuat (technical and office
protocol-TOP) la tieu ehuftn do Hang Boing Computer Service phat trien, kM giong MAP nhung gia re
VI si'r dl,lng h~ thong bang co sd. IDnh 2.78 the hi~n mQt m~ng TOP. Khac v6i MAP trang lap 1 va 2 si'r dl,lng ho~c truyen thong bao v6i m9t vong IEE802.5 ho~c t6 chuc tham nh~p nhicu moi bang cam nMn song m~ng c6 do xung d¢t
(CSMA/CD) viii m<), mang buy'- Cung nhu v~y d lOp 7 cae giao thue
Tr~m
! May I ,I Tram
~ £ong SI .:
T~ bao '
: di~u khien
Hinh 2.77: Giao fMe MAP
Tram 1 ~
Ilinh 2.78: Giao ,h/re TOP ling d~ng c~ the lien quan nhieu den yeu cau cua m9t van phong hem Ia uoi hoi cua m9t m~t bang san xuat. Theo phuemg phap tham nh~p CSMA/CD. m6i nut
deu co quyen blnh d~ng trong vi~c tMm nMp vao kenh truyen nhung pMi nghe ngong truoc khi truyen xem c6 sl! truyen nao khae kh6ng.
Cae kiln Ink hif th{/flg mqng (systems network architecture- SNA) do IBM
phat tri~n lil tieu chufin thi€t k€ cho san phfim cua IBM. SNA duqc ehia thanh 7 lOp. Cac lap nay kMc voi cac lOp eua OSI khong nhicu, ehu yeu la khac d lOp 4 va 5.
Mqng c()ng nghi¢p Profifhus duqe phat tritn va to chue bdi PNO (Profilbus
User Organization) la m~ng truong thong tin rna, chufin hoa theo tieu chu&n chau Au. tuy theo ling d~ng c~ the c6 the' lil.: PROFILBUS-t"'MS (Thong tin
dicn fa giiia cac thiet bj dieu khien PLC, PC); PROFILBUS-DP (thi€t ke d~c bi~t cho ca.e m<).ng ghep n6i tl! d9ng giiia cae h~ thong tl! d¢ng hoa v6i cae thiet b! philn tan). Kien truc giao thti'c ella m<).ng cOng nghi~p PROFILBUS tuan thil
cau truc 7 lap nhu OSI nhung kh6ng si'r u~ng cac lOp J~6. Ngoai ra con m(it
2.5.3.3. Cae ehu~n giao di~n
Ciic chuan giao di~n Hl thuQc lap giao di~n v~t If trang mo hlnh tham khao
osr (Open Service Interconection), lien quan den d~c tfnh ki thu~t v~ co clla d.p va colC b¢ noi, d~c tinh di~n moi noi, cac mieu ta chuc nang cua giao di¢n g6m rnicu ta d~c tfnh chan dm - tin hi~u va d.c dinh nghia tin hi~u, d~c tinh dc thu n1C eM di~u khien va truyen tai dfr li~u.
Churin giao di~n pho thong nhat la cang RS232, do American Electronic Industrie Association (EIA) dinh r6 tinh chat van nam 1962. Chuin giao di~n lien quan den thiet hi dau cuoi dfr li¢u ( data terminal equipment -DTE) va thiet bj m<;1ch driu cu6i dfr li¢u (data circuit- terminating equipment -DCE): Thiet bj d,l.u cuoi dfr li¢u c6 the nMn hoijc gi'ti dfr li¢u thong qua giao di¢n den m¢t b¢ di~u khien. DCE cung cAp ket noi cho DTE va~ m;:tng truy~n thong va nguqc l<;1i. Ngoai ra, DCE con ket thuc va khoa m;:tch. Khi duang truy~n di¢n tho;:ti tUo'ng tt! (analog) la moi tfl1O'ng truy~n thong thl DEC 1.1 m¢t modem. Khi uuang truyen la so thI DCE la M djch vl,l kenh ho~c M dich vl,l dfr li~u.
Ngoai chu.1n RS-232C va RS-232-C clla EIA con co d.c chukin V.24 ella
CCIlT (Comite Consultarif International Telegraphique et Telephonique). cac chudn DTE/DCE kbac g6m RS-366A cua EIA, X.20, X.21 va X.35 cua ccrrr.
2.6. MODUN Xl! Li
Modun xU If, xiIlf thong tin do modun giao di¢n va mbdun do luang cung cap. Thanh phan chfnh clla mbdun nay Ia bQ dieu khien. Ngay nay cac bQ vi xu 15' (j.lP) dong vai tro quan trQng trong cac bQ di~u khi~n. Do c6 rAt nhi~u lo;:ti )J.P, tir dem gian den phuc t;:tp hi¢n dang co tren thi twang, nen tren co sij cau truc bQ
Xlr Ii clla may vi tinh co the dua fa m¢t tbng quan ve diu truc clla)J.P nhu sau;