The captures show that both clocks are between ~21khz & ~32khz, so I don't think that's the issue (I should of included more timing information in screen prints).
I decided to hook both up to the controller at the same time (expected collisions). What I found was that the arduino worked as expected, but the crio also produced additional data (although not 100% correct).
What I found was that although the DSC says it's a LEGO compatible port, it doesn't provide the 5v 10k pull-up on the analog port (white wire) that the NXT brick does.
The HiTechnic controller uses the voltage to determine what I2C address it will listen on (not sure of the details, but it allows the controllers to be daisy changed without address jumpers). Since the DSC left it floating, the controller didn't assign itself the 0x02 address that I was expecting.
All is not solved yet... When I added the pull-up and removed the arduino, I now see the expected NUMBER of requests, but no matter what registers I request data from, it always returns 0x03.
I'm going to double check the electrical characteristics of DSC LEGO port and see what else might be different.
Although I was hoping for a plug and play solution, I can live with having to make a custom cable to account for electrical differences.
Now to just get rid of those 3's!!!
