Hello, I'm programming the MCB167NET ev. board. I've conected externally the interfaces trying then to simulate a network with only 1 board, making it connecting the pins 2 and 7 respectively(CAN_L to CAN_L and CAN_H to CAN_H). All the jumpers seems to be ok. The problem is that the 1st interface detects bus off (before and after initialization) but the 2nd never. What can be wrong?
The cabling you created, as described, is not a valid CAN bus. It cannot work like that. You need at least one termination resistor on your bus. The fact this was apparently not obvious to you hints at a serious lack of understanding of what CAN bus is, and how it works. In other words, you appear to have no idea what you're doing. Please do yourself, us, and your project the favour of brushing up on basic knowledge before you go on plunging head-first into unknown waters like that.
I've heard of using CAN without a transciever but have never tried it. Here is an appnote that might help though. http://www.infineon.com//upload/Document/cmc_upload/migrated_files/document_files/Application_Notes/ap292101.pdf
the can bus basicalloy is a RS485 driven by a CAN protocol. Thus a lot of good knowledge can be found in "ten ways to bulletproof RD485" found here http://www.national.com/an/AN/AN-1057.pdf Erik By the way, anyone attempting RS485 without reading this one first is wasting time.
I've heard of using CAN without a transciever but have never tried it. That's not what the OP was doing. He's trying to do CAN with transceivers (otherwise he would have TX and RX pins, not CAN H and CAN L), but without termination, and probably without a clue.
That's not what the OP was doing. He's trying to do CAN with transceivers You're right, my mistake.
Hans-Bernhard Broeker ... CAN1, CAN2: Default ON The CAN1 and CAN2 configuration jumper enable on 120 ohmns termination resistor on the CAN1 or CAN2 bus interface. This resistor is used on the end of each CAN communication line. ... I said that theese jumpers was ok. It's true that I'm a newbie but, maybe, the person who not have idea this time be you. Thank's, erik malund, for the guide, i'd take a look and it's really complete, but the problem persists, it would be due to the lack of shielding because the power conector is near; sometimes the second interface detects buss off but most of the attempts seems to be ok it's enough strange. I will trying to discover what can cause this.
"I said that theese jumpers was ok" Actually, you didn't mention any specific jumpers, and you only said that they "seems" to be OK. "maybe, the person who not have idea this time be you" Maybe he has no idea about the specific board, but why should he? I think it's up to you to say, for example, "bus is correctly terminated by jumper settings"...?
Ok, I simply felt abused and that's the reason for my stupid reply. Sorry.