RE: I connect my device to a truck's can port (J1939) , the truck present an error .

A couple of remarks:

 

1.       Use the proper tools for diagnosing, i.e.: a scope and a CAN analyzer. With any half decent scope you should be able to visualize physical/protocol errors on the bus; CAN analyzer software gives you a proven CAN interface (i.e. tested and functional) and a proper view on bus activity, error statistics and error frames.



2.       It is not because the pure CAN part is OK, that all is fine and dandy. Depending on the HLP, other nodes on the bus may respond to frames that they consider to be malformed or unknown. If you want to transmit anything on a CAN bus (especially if it is running a great big chunk of steel with wheels), you should be aware of the proper way to do so (preferably through documentation that is supplied by the designer of the network). Every node should have their own set of IDs that they can use to transmit, and if your node is using one of those, the other node may throw a hissy fit because you’ll sooner or later end up with arbitration errors.

 

With all due respect: if you have any doubts about proper operation, don’t connect your gizmo to critical CAN networks of something that is big enough to kill you. Most critical in-vehicle networks are designed to degrade gracefully in case of failures, I’m not sure what happens in the case of active interference. 

 

Cheers,

Bram

 

From: [email protected] [mailto:[email protected]] On Behalf Of c yl
Sent: maandag 19 januari 2015 10:56
To: [email protected]
Subject: [CANLIST] I connect my device to a truck's can port (J1939) , the truck present an error .

 

Hi Everyone:

 

    I'm connecting my can port of an arm7 board (lpc2478 with ecos which works all OK) to a truck's can port, and the truck presents an error: I think its communication error or something. And at the same time my board can receive can packages right. If I set my can port to listen only mode , the truck tells no error, and I can receive can packages but I can't send then .

    Can anyone tell me why the truck tells error when my can port works at a normal mode? Should I work only in a listen only mode?