PDA

View Full Version : Issues with daisy chained Jaguars


keshavdv
01-20-2011, 10:07 PM
Hi everybody,

Our team is having issues getting 4 daisy chained Jaguar speed controllers to communicate over the CAN interface. The Jaguars are connected as follows:

CRIO <--> Black Jag <--> Brown Jag <--> Brown Jag <--> Black Jag

While using BDC-Comm, the program finds all the speed controllers and can communicate with each one. When we try to create CANJaguar's in Java, we can no longer communicate with anything past the first black Jag. Occasionally, the code does find more than one but after a power cycle, the problem comes back and only one is found.

So far, we have not been able to successfully communicate with all four Jaguars for more than a short period of time. We are planning to use the CAN protocol this year but want to make sure that it works consistently before moving on.

Has anyone else had similar problems and if so how have they fixed it?

ratdude747
01-20-2011, 11:00 PM
question: were you using the same serial adapter for both the bdc-comm hookup and the cRIO? If not, are you sure the cRIO's adapter has good termination?

drakesword
01-21-2011, 11:49 AM
We had a similar issue. Turned out to be the terminating resistor on the cRIO side had poked through the insulation and shorted on the casing (tied to ground). Was a headache to find. . .

keshavdv
01-21-2011, 02:33 PM
Thanks for the help....We figured out that we also had an issue with the termination in the RS232 to RJ12 cable.