CAN performance for 2012 (2CAN?)
 

A while ago, Kamocat ran some tests on the performance of FIRST's CAN using the black Jaguars as a serial-to-CAN gateway (documented at http://www.chiefdelphi.com/forums/sh...ad.php?t=86259). During the 2011 season, I did some tests of my own to see if it had improved.

What I found was that we would average 180-200 CAN commands per second (this would vary based on the command). Principally, I tested using the voltage set, current control setpoint set, and current reading retrieval commands. It was done in Java, over a serial connection from the cRIO, utilizing a mix of black and tan jaguars. The CAN network was properly terminated and appeared reliable.

Since we had 4 drive motors, that comes out to a 45 Hz update rate (voltage set commands would only run at about 180/sec). As this doesn't enable new functionality (we had no need for closed loop control if we couldn't also read the voltage being output), and this was slower than the PWM update rate, we chose not to use CAN.

I am wondering if this will improve this year, or if the 2CAN offers improvement. Have other teams run similar tests with the 2CAN? Have any beta test run tests such as this with the new software? Has anyone heard anything about possible performance improvements?

Mainly, I'm wondering if the 2CAN is worth purchasing -- we don't have one, but if it offers a significant improvement, we'll buy one. Unfortunately, according to the thread I linked to, it doesn't look like it does. Am I wrong?

Thanks for any responses.

EDIT: Looks like the PWMs are updated at almost 200Hz... should've read the documentation better (that would've been really nice to know last year).