CAN Rules
 

I am reading this correctly that every team is required to use CAN?

Also, R40 defines acceptable positive and negative wire colors, but I see no rules that define CAN wire colors.

Re: CAN Rules
 

Correct. Don't be afraid. This is a different implementation of CAN than in the past.

CAN wires are signal wires. No signal wires have color requirements.

Re: CAN Rules
 

Though the green and yellow wires in your kit will match the coloring on the connectors so that may be a wise choice.

Re: CAN Rules
 

Of course, but virtually the entire control system uses the Red:+, Black: - convention, and you could use White:+, Blue - if you wanted to.

It is a differential pair, not signal and ground. It should be a twisted pair.

Re: CAN Rules
 

It should be twisted, but does not have to. During beta testing, we were running it using non-twisted to a worse case than using twisted, no issues.

Re: CAN Rules
 

If you want to twist your own cable...

https://www.youtube.com/watch?v=YAquFszYZ1k#t=75

Re: CAN Rules
 

It is not really a "balanced" signal but it is a transmission line. You will need CAN enabled if you wish to use the pneumatics PCM module and turn on your compressor. As always, CAN implementation requires a terminating resistor at each end of the buss. One is provided in the RoboRio (The start of the buss) and another is provided in the PDP (possible end of the buss). If you wish to configure your CAN wiring differently or not use the PDP CAN, then be sure to provide the required termination resistor at the last device in your chain. The majority of CAN problems in the past have centered around the termination resistor.

Re: CAN Rules
 

Per R61, PDP CAN is required.

Re: CAN Rules
 

Thanks Joe, I forgot we included that. This gives the battery voltage reported by the PDP, right?

Re: CAN Rules
 

Just to avoid confusion, CAN to the PDP is required (and to the PCM if you use pneumatics), you can still use PWM for motor control.

Re: CAN Rules
 

CAN is required to talk with the PDP, but the upside is that you get to learn what all your load currents are!

Re: CAN Rules
 

The battery voltage is monitored by the roboRIO. I assume the PDP requirement is so the DS and/or field can monitor currents.

Re: CAN Rules
 

Correct. :)

Re: CAN Rules
 

The 4 ft of green/yellow wire is enough for some short runs for PDP and PCM connections. We plan on using CAN elsewhere as well.

I have not found a good source for green/yellow twisted pair. I know it doesn't have to be the same color, but it's good consistent reminder and it's our school colors. :-)

Does anyone have a good source for the green/yellow twisted pair wire?

Thanks