Serial to CAN Gateway in new Black Jaguars?

[EricVanWyk]

Originally Posted by ajlapp

Are the CAN connectors on the Jaguars able to pass data through if they have no power. Are they simply unions or is the Jaguar doing something with the info?

The CAN connectors are pass throughs, and do operate without power. The Jaguar does not act as a repeater.

Originally Posted by ajlapp

From my experience with automotive CAN bus layout, we always have a main trunk with a terminator. Each CAN device then has a direct link to the trunk...nothing is daisy-chained. Would this help eliminate failure concerns, excluding losing the main Black Jaguar or the trunk line?

CAN is nominally a daisy chain / trunked layout. What you are referring to is a "vampire tap", a short deviation from the trunk. The signal reflects off of the end of each of the taps, which can cause signal integrity issue if the tap is too long for the bitrate (when in the bitlength does the reflection hit)? If they are kept short and the bit rate is kept low, its a perfectly reasonable way to run a CAN bus.

We decided that it would be better to avoid the issue entirely and go with a purely daisy chained approach. This allows for a higher bit rate and is much easier to assemble and is cheaper. Also, I'm not entirely convinced that a tapped topology is more reliable; Who is going to make the wiring?

I'm not saying that tapped is universally inferior to daisy-chained. I'm just saying that it isn't appropriate for FRC.