> =

> I've got enough working that I can enter commands in a test app on the PC,
> which sends commands over the USB, which causes the host CAN controller to
> send a frame, which is received by another board, which causes it to wigg=
le
> some I/O lines.

How is this generally working with USB and CAN compared to serial RS232/485 =

regarding commands and confirmation of the command?

When I do this with a master/slave protocol with RS232 or RS485, I generall=
y =

have a command and a reply to that command. If I get the reply as expected =
I =

can count on that the receiver has received the command and executed it =

(updated the I/O lines in this case). If I don't get a reply I will general=
ly =

try a couple of times and then give up, assuming the receiver is not there =
or =

is broken.

My understanding of CAN is that the communication is oriented around the =

content of the message (or message type) rather than around a particular ma=
ster =

and a slave node. Whichever node that is interested in that type of message =

acts upon it.

So, if I want to build a network with CAN rather than RS485 and use it with=
 my =

master/slave type of protocol, can I do that in similar way (at least as se=
en =

from the master side)? Or do I have to make another layer inbetween my =

master/slave protocol and the CAN communication that reserves a couple of =

message types for a command and a reply and then have the address node toge=
ther =

with the actual data inside the CAN data frame for that message? Send the =

message for the command and wait for the reply message type and check that.

And if I have a sensor I want to read the information from, do I tell it to =

send the data or is it generally sending the data continously and I just pi=
ck =

up the message from that when I need it?

And what about USB? =


/Ruben





=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124, 200 39 Malm=F6, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
ruben@pp.sbbs.se
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist