Black Jaguar CAN Issues

[Radical Pi]

Originally Posted by Mark McLeod

You see the problem. This is a CAN-bus we're dealing with, not an alternating CAN/RS232 hybrid. A CAN-port won't talk to an RS232-port of course, they speak different languages.

The Black Jaguars are intended only as a converter from RS232 to CAN at the start of an uninterrupted CAN bus, they don't have enough CAN ports to form a traditional CAN daisy chain, only the Gray's have the CAN ports to continue a daisy chain.

That's not quite true. While CAN and RS232 are completely different, the wires for them are also completely different. If you put together the RS232 to CAN adapter, you put a resistor between the Red and Green wires. Those are the 2 CAN wires. All the other ones plugged into the DB-9 connector are the Serial wires. As long as the CAN to CAN cables were assembled properly (double check that btw), 2 Black Jags should be able to be on the same bus.

Also, try messing with your configuration. Change the order of jags daisy-chained, try a different jag as the serial to CAN, swap around cables. You might have happened to put a bad connection between the source black jag and the 2nd one, breaking the bus

[dyanoshak]

On a Gray Jag the two ports are both 6-position 4-conductor (6p4c) modular plugs. On a Black Jag the left port is 6p6c and the right port is 6p4c. The extra two conductors on the left port are serial lines. This means the left port on the Black Jag is dual function, and can be daisy chained like the Gray Jags in the CAN-only part of the network.

[EricVanWyk]

I found the "enumerate" function to be really helpful for this sort of stuff. I don't have LV in front of me at the moment, but this command will tell you what IDs it sees on the CAN bus at the moment. I just stick it in a slow (5 second?) loop and have an indicator hooked to the output.

This will give you a better idea of what is going on.

[taichichuan]

Hi Gang,

When I run into these sorts of problems, it's almost always related to bus termination. The approach of putting the terminator into the RJ-12 is simply too prone to shorting out. It's best to run a short length of wire out of the RJ-12 and solder the terminator externally w/ some heat shrink to keep it safe.

HTH,

Mike