Hello,

look to this pdf:

ftp://lorca.act.uji.es/CAN/CAN%20bus%20specification.pdf

Also quick look attachment.

Thankyou for your reply.

My question is that for example a COB for an emergency message would be 080 + NodeID. In case of 11 bit identifier the resultant of 080 + NodeID will be an 11 bit identifier. what will be the COB-ID for a 29 bit identifier. will it be divided such that the firat 11 bit slot will be the same as that for the standard can frame and the rest of the 18 bits will be filled with zero?

Hello,

logically yes, but why I will be used extended format if I have only 11 bit resolution for messages? Can you pls post your reason of question? Simply if you read my sugested pdf, there is recommendation using old 11 bit messages system if you don't need more messages. Also new modules with extended CAN are back compatible as is stated in document.