CAN timeout

[hannigan]

Hi,
This is our first year using CAN (serial connection, not 2CAN yet) for connecting our Jaguars, and we have been having some trouble with timeout. We were able to daisy chain any 5 jaguars together, but when we get to the 6th one, the code says that the jaguar timed out.
We tried different cables, and we tested all of the jaguars in this 5 jaguar chain and they all worked. Is there a limit to the number of jaguars we can have in the CAN daisy chain? Has anybody else had this problem?
Thanks

[anthonyttu]

You are well below the limit. We have had this issue if we miss number any of the Jaguars.
I would check/ renumber the Jags and verify the code is also correct.

[Jon Stratis]

also, verify you have the terminators (100-ohm resistors between the middle two pins) on both sides of the CAN bus.

[hannigan]

Thanks, I double checked it and it seems to be wired correctly. In the db9 connection to the crio, I have the resistor connected between the red and green wire. For the terminator at the end of the daisy chain, I have a rj11 connector with a resistor in the middle two contacts. Is there anything else that I may be looking over?
Thanks

[Jon Stratis]

I just noticed your local here in MN... Any chance you guys are going to the pre-ship scrimmage at Simley on Saturday? We have a couple of students who are experts on CAN (we ran 7 Jags last year with it) who could help out there!

[hannigan]

Yes we are! That would be great. We are Inceptus team 2264, I am Emily, the electrical manager. I will stop by your pit on Saturday.

[Jon Stratis]

Awesome! We'll make sure to hook you up with our programmers, and we can double check all of the wires and connectors to make sure its not an electrical problem. We'll see you there!

[Kevin Sevcik]

Originally Posted by hannigan

For the terminator at the end of the daisy chain, I have a rj11 connector with a resistor in the middle two contacts.

I would look at this end very carefully. If you've actually crimped the two bare wires on a resistor in an RJ11 connector, this could be your problem. Or a problem, anyways. Someone tried that on our team, and the bare wires were so close together they ended up making intermittent contact. That would short the data pins together with predictably bad results for the network.

Also, the CAN network is limited to a total length of 20 feet. If you have a bunch of 4 foot CAN cables for some reason, that last jaguar could be pushing you over the maximum length.

[jp1247]

One of the problems we have is our first black jag, the pins on the serial side are not bent out enough, so we have to bend the connector on to the pins by pulling the cable back and zip tieing' it somewhere. Try holding the cable bent right at the connector and try loading code, try again in the other direction. You could also try a piece of plastic or a screwdriver in between the clip and the connector housing.

[Joe Ross]

How many messages are you sending/receiving per second?