Vex Competition Error


At a competition last week, my team’s robot functioned fine outside of the competition field and when not connected to the VEXnet Field Controller. When connected, the autonomous would work fine, but the during the driver controlled period the robot would lose functionality after about 5 seconds. It acted as though it was losing connection to the remote. We attempted turning the controller off and on and after it regained the connection it would repeat the issue.

We did connect to a manual competition switch and could not replicate the issue outside of being connected to the Field controller.

Has anyone else experienced anything like this and if you did what was your solution and what is the cause to the issue?

Thank you:D

Did this happen on different field controller cables/units? Do you know what the lights on the controller were when it DCed.

Were the controller batteries charged?

It happened on both fields that were set up and with multiple cables.

The batteries were charges and they even changed batteries with fresh ones multiple times throughout the day.

They aren’t positive on the lights but they believe all the lights were still green.

If all the lights are still green, you were still connected and the field control was most likely working fine.

It might have been an issue with the robot tripping PTC thermals in the motors or Cortex. but that wouldn’t explain why it was only on the field.

Just curious as to which tournament. We had the same thing happen 2/14. In the pits, things were fine, but at the field, there were problems. Several teams were having the same issues.

The event partner said he thought it had something to do with someone trying to steam video of the tournament and that was causing RF interference. Near the end of the tournament, they finally shut the person down.

Hmm, not sure how streaming video would interfere with VEXnet connection.

What this does sound similar to is when the robot disconnects after being unplugged from field control. I don’t know if it’s on purpose or just coincidence, but usually once given the all clear after a match we will unplug the controller to lower the lift or move closer to the edge of the field. After a couple of seconds of being unplugged, the controller will disconnect and not connect again. I think that all lights are off except for VEXnet (maybe) blinking red slowly.

Is your robot not responding to the joystick at all or is it trying to move but only able to twitch?

They were streaming it with a wireless connection to the net. I am not saying that was the issue for sure, but it is possible as the Vexnet system is on a bandwidth that overlaps a lot of wireless communications. According to a friend of mine that deals with this stuff for a living, it is theoretically possible for there to be interference from other wireless communications in close proximity.

His explanation was way above my understanding but I will take his word for it as this is what he does for a living.

New account, I am the student whose robot wasn’t functioning
The robot would function for a short ~5 second period and then cease function. At times it would twitch but no real movement. We unplugged and replugged the connections multiple times during one round to see if that would fix the issue, and it would work for another few seconds and then fail once again.

We were in Las Vegas at Hyde Park MS