Intermittent connection on field only

[Joe Ross]

We're competing at the LA regional this weekend, and are having nothing but trouble when competing on the field. We lose communication at completely random times (moving, not moving, before match, during match, etc), and for random durations (for anywhere between a few seconds to almost the entire match). However, this only occurs when we are on the competition field with FMS, but has happened in every single match. When we run tethered in the pit, tethered on the practice field, and wireless on the practice field (with the practice field radio), it works perfectly, no hiccups.

We've replaced the following components, with no effect: cRIO, radio, ethernet cable, driver station computer, and radio 12-5v power converter. It occurs with the default LabVIEW code as well as our own code. We pulled every single circuit breaker, so that the only items powered were the cRIO and the radio, and it still occurred. We've had multiple people from our team, other teams, and event staff check our wiring, and wiggle the wires looking for shorts or loose connections, but haven't found anything. Our chassis is open to ground. cRIO is mounted to wood, and the camera is mounted to plastic. Our radio is mounted pretty high, and not overly surrounded by metal. The closest motor is around 12 inches away. We are not using any of the banebots 775 motors.

About the only control system component that we haven't replaced is PD board. I've used a DMM to look at the 24v and 12v power supplies, and both seemed fine. 24v supply was at 23.9v and 12v was at the battery voltage (12.5). I didn't see any change when communications dropped. While everything seems good with the PD board, since it's the only thing we haven't changed, I'm worried it's our only choice tomorrow. The PD board is brand new from the kit this year.

Any ideas or additional troubleshooting steps?