CAN with more than 2 Jaguars

[KillerGardevoir]

I am having trouble setting up CAN with more than 2 Jaguars (black to gray). I have tried everything i can think of to make it work, all the cables work, the terminating resistor works, the jaguars work, the RS232 to RJ-12 works, we are connected to a computer with an serial port (no usb emulator), the firmware has been updated to revision 87. It can see two by putting a black then a gray with the terminating resistor, but the moment I attempt to attach a third jag (gray or black) to the network it can only see the first in the series. Also I can't seem to get two black jaguars to connect together.

[Radical Pi]

Have you setup an ID on the grey jag? All jags default to ID 1 and if multiple jags share an ID the bus gets messed up. Also have you tried switching up the cables? Perhaps you didn't make the second cable properly

[KillerGardevoir]

I have done this already, double checked the ID's and we have 4 cables that are verified working.

[KillerGardevoir]

Ok so I resolved the issue, it turns out it was the cables. Two were fine, but the other two were damaged, so they have to be remade. Long story short, show all team members making cables how to properly make cables.

[Alan Anderson]

Originally Posted by KillerGardevoir

...the terminating resistor works,...

You need two terminating resistors, one at each end of the bus.

It can see two by putting a black then a gray with the terminating resistor, but the moment I attempt to attach a third jag (gray or black) to the network it can only see the first in the series.

That would not be unusual behavior if you're missing the resistor at the beginning of the chain. Termination problems regularly manifest themselves at the other end of the bus from the fault.

[cmoon71]

We are having problems using more than 3 Jag on the CAN bus. Using the BDC-comm, when we add a 4th Jag, all we can see is the 1st Jag! We are using 120 ohms as a terminator between CANH (3) and CANL (4) plugged into the Last Jag on the bus as Black Jaguar 2010.pdf shows. Is this right?

[Alan Anderson]

Originally Posted by cmoon71

We are having problems using more than 3 Jag on the CAN bus. Using the BDC-comm, when we add a 4th Jag, all we can see is the 1st Jag!

Is the terminator at the cRIO end of the bus connected properly?

[taichichuan]

I've found that the approach of placing the terminator resistor into the connector, as shown in the GSG, is way too prone to shorting out with repeated insertion and removal cycles. I feel that your best course is to run the wires for the terminator a short distance out of the connector and solder/heat shrink them outside of the RJ-12. That seems to stand up better and avoid the easy short that happens when the two resistor legs touch each other in the connector (they're on adjacent pins).

HTH,

Mike

[TRay]

True, but a little hot glue fixes that quite well.

[biojae]

Originally Posted by TRay

True, but a little hot glue fixes that quite well.

Or epoxy works too, but crimping that little resistor in was a pain.
As a matter of preference, solder, but as far as aesthetics (And difficulty of removal ), crimping.