CAN Bus

[me[R]a]

Jedan moj drugar bavi se odrzavanje masina za preradu koja se koriste u industriji mesa. Neki dan me je pitao da li postoji mogucnost da se napravi jednostavan CAN Bus tester. Ono sto mi je opisao ukratko jeste da mu treba da se nakaci direktno na CAN devices i da proveri dali se odaziva na CAN Bus pozive. Posto je meni to totalno strano postavih pitanje ovde jer mozda ima neko da se bavio takvom potrebom.

[vladd]

Ne.
CAN jeste parcijalno standardizovan protokol, medjutim, svakom inzenjeru je ostavljena sloboda kodiranja infomacija u okviru paketa. Na CAN se prikljucuje uredjaj koji ce da sebi dodeli status mastera i da proziva komponente mreze.
Jedino da mu neko "jednostavno" doturi hakovan ili fabricki test jig.

[Аритон]

paa nije bas tako, uredjaj kojim se cita can, van i ostali protokoli ne dodeljuju sebi master status.
koji oni tacno uredjaj ili masinu, model sa can komunikacijom koriste industriji mesa?

[gorankg]

Najjednostavnije i najjeftinije da to uradi preko ELM327 OBD skenera. Treba samo da proveri na kojoj brzini radi taj njegov CAN i da uporedi to sa ELM/om. ELM ima monitor mod u kome može da sniffuje CAN bus i preko njega može da se vidi šta pričaju uređaji na bus-u. Tako dobru spravu za tako malo para ja još ne videh.

[vsavic]

Da se nadovezem na Goranov post, za ovaj Elm, ima i Android i iOS aplikacija preko koje moze direktno da se salju komande i vidi response (posto ima ugradjen BT)

[gorankg]

I još bolje. ELM je ustvari PIC mikrokontroler, sad je valjda neki iz serije PIC24xxx, pa kome treba neka posebna funkcionalnost za CAN može da iskoristi ceo hardver jeftinog kineskog uređaja i "samo" napiše softver. To pisanje softvera i nije komplikovano jer ima dosta primera.

[Аритон]

mozda i moze da prodje elm ali pitanje je, tacnije treba proveriti prvo koji protokol je na toj masini.
Ako je obd2 odlicno ali ako ide preko k-linije ili vana nece da moze...



ps
ukratko


CAN CONNECTION LINES - DESCRIPTION
This vehicle is equipped with a CAN (Controller Area Network) system of electrical connections: it involves a software and
hardware solution which is designed to manage the resources on the vehicle efficiently allowing:
? the sharing of information between the various electronic units;
? the intergration of several electronic units through one network;
? a high network information exchange speed;
? advantages in economic terms because there is a considerable reduction in the wiring/connectors inside the vehicle;
? superior standards in terms of quality and reliability.
The advantage of using a CAN system stems from the fact that communication takes place between numerous control units and
consequently the number of signals to be managed is very high.
For this reason the signals travel on a CAN type serial Bus where one wire is high level (H) and the other low level (L); these
signals on the CAN Bus are differential types, i.e. the value assigned to the bit is represented by the difference between the CANH
and CAN-L voltage levels.
The different electronic units which make up the system, known as network nodes, are connected to the CAN by means of
communication interfaces known as transreceivers; these connection interfaces, integrated in the electronic units, constitute the
gate for sending/reading the information at the CAN or at the serial lines.
The exchange of information at CAN type serial lines is only possible using a transmission protocol which is the collection of rules
that allow communication between two or more nodes by means of the exchange of information or "data packages".
The main element of the network is the Body Computer.
The Body Computer node is entrusted with "waking up the network" when the ignition key is turned to the ON position (if there is
a problem with the Body Computer this task is entrusted to the instrument panel).
The Body Computer also carries out the functions of checking the network which make it possible to provide information on:
? the network activities status;
? the functional failure status of the individual electronic units (nodes);
? a possible CAN fault.
The various electronic units process the various signals coming from the corresponding sensors both for their own management
and for other control units to which they are sent via the CAN.
The specific structure adopted for this vehicle consists of two CAN communication networks which connect nodes belonging to two
different areas:
? C-CAN for dynamic vehicle control (high speed): bus CAN-H and CAN-L;
? B-CAN for the management of standard body functions (low speed): BUS CAN-A and CAN-B; the two CAN communication
networks are connected to one another by a gateway for transferring joint information, located in the Body Computer
Node.

[Аритон]

mozda ovako nesto

http://www.ems-wuensche.com/product/manu...m7-d-e.pdf

http://www.ems-wuensche.com/product/data...cgarm7.pdf


http://www.ems-wuensche.com/product/data...garm7.html

[me[R]a]

Hvala na odgovorima ali vidim ja da tu nije nista lako ni jednostavno.

koji oni tacno uredjaj ili masinu, model sa can komunikacijom koriste industriji mesa?

Spominje LENZE koji koristi System Bus CAN300

[vojinilic]

Ne postoji protokol kod CAN bus-a. CAN bus podrazumeva kompletan OSI sloj, tj. od fizickog, do aplikativnog i kod njega je sve jasno definisano. Tacno se zna sta je sta. Takodje ne postoji master, a ne postoji ni slave, vec je bitan ID poruke.
Bilo koji CAN bus driver ce da ti prebaci komunikaciju u format za PC ili MCU, a na tebi je da parsiras ove poruke.
Projektovanje softvera za te svrhe nije trivijalni, zato je moj savet da poslusas Gorana sa njegovom preporukom.
Protokol ovde nije cisto bajtovski, tako da ima malo vise zezanja oko prijema i tumacenja.

[ZASto]

Čini mi se da bi LENZE trebalo da se relativno lako poveže preko CANOpen.
Čini mi se da sam tako nešto viđao na jednoj žabarskoj mašini sa 3 servo drajvera.
Nemo' me držiš za reč, ali koliko me sećanje drži, kačeno na neki mali PC pod linuxom.

[Аритон]

ako je to ovo, tesko da ce tu elm raditi

https://www.helmholz.de/fileadmin/docume...300_18.pdf

http://download.lenze.com/AKB/English/20...bus_1a.pdf

http://download.lenze.com/TD/DDS__System...-0__EN.pdf

[gorankg]

Zašto? ELM podržava 11bit i 29bit ID mod. Problem mogu da budu brzine jer ELM ne ide preko 500kbps ali ga ništa ne košta da proba ili možda smanji brzinu na tom Lenze.

[ZASto]

Teško će na tom Lenze da smanji brzinu.
Treba poseban interfejs i poseban kabl za povezivanje sa, npr, servo drajverom, ...

[Аритон]

Da, zbog brzine...
Naravno, ako ima vremena i volje neka proba covek.
Ja sam od can odustao, ne pratim, bosh je ove godine imao lokalnu prezentaciju bnovog sistema bez can-a i njima slicnih anemicnih...