one node in the network if it is trying to send the data wha

prabu · Joined: 29 Jan 2015 Posts: 8 Location: india chennai

one CAN node in the network if it is trying to send the data what happend to
that data? no recevier

Ttelmah · Joined: 11 Mar 2010 Posts: 19538

A transmitting node always looks at it's own data (this is how collision detection is done in CAN), so the transmitter also receives it.
If you ignore this self reception, you are getting into philosophy, not electronics (If a tree falls in a forest and no one is around to hear it, does it make a sound?).....

RF_Developer · Joined: 07 Feb 2011 Posts: 839

If there is only one node in a CAN network, if it tries to transmit a message it will continually retransmit it as there is no other node to acknowledge it. With PIC hardware and CCS driver, what happens is that the hardware transmit buffers fill up and the driver hangs waiting for a free buffer.

CAN does not have addressing (any addressing is done at a higher protocol level) and all nodes always acknowledge all messages so as soon as ANY other node is connected to the network at the right speed, even a CAN monitor, then the block is cleared and the packet is transmitted. It doesn't matter whether any node listens to and uses the message, all that matters is that the network has a node to acknowledge the message.

CAN is essentially "realtime". Messages do not have any "lifetime" on CAN as they do on some other networks. The message "exists" only while it is being transmitted.