Field disconnections and match replay

Yesterday (February 22ed) my team, 2158Z competed in the Dallas regional state championship, for the majority of the day we were doing very well and for a while were in first place. After our lunch period (12-12:30) however we started to have connection issues with the field, in one match (qualification match 67) our robot disconnected from the field for the entirety of the autonomous and majority of the driver control period. We had fully charged batteries (main battery was at 8.65 volts, the backup was at 8.95), we had driven the robot around only seconds before connecting to the field, the robot and vex net lights on our cortex and controller were on green additionally the controller power light on our controller was also green. Our vex net keys were fully plugged into our robot and secured down with tape to ensure they would stay in place. We turned everything off, plugged into the field and turned back on this is when we encountered the issue. Our robot and vex net lights once more showed green lights, our game light however went straight to red. Once the match started we had no control over the robot, the auton didn’t run. Our robot lights indicated that we had full connection to the field, that our robot was connected to the controller. We then checked our lcd display to make sure something hadn’t gone wrong, the lcd said that our robot was still in disabled mode. We checked to make sure the battery was plugged in, it was. A rec Representative came over during the match to see what was going on, they could not reach a conclusion. We power cycled everything twice more, the rec representative unplugged my controller from the field and suddenly our robot was able to work once more. We talked to the ref’s about what had happened and what to do about it. They told me it was a field issue, that they were unsure what caused it but that i would simply have to go with the score that my alliance got. a rec representative talked to me one on one after the match, we and tried to simulate what had happened to find out if it was a field or user error, we tried to unplug the battery from my robot partially, unplug the back up battery, connect the robot to the field using various methods, however nothing seemed to be able to reproduce this elusive situation. We have gone to 8 competitions this year and have never encountered this issue, the issue never came up again in the competition. Rule G7 states that the robot who’s connection with the field is in an improper manner, one which alters the outcome of the match is not permitted, this connection with the field issue had a significant impact on the outcome of the match, and cost us our high ranking position, while it is impossible to speculate whether we would have won or lost more matches in the elimination portion of the tournament due to this issue, we can confidently say that this issue did effect our outcome. The head ref said that he refused to redo the match, due to time constraints even though we were 15 minuted ahead of schedule. We understand that the replaying of matches is up to the head ref’s decision however we would like to know what would have the proper action to take in response to this problem, and furthermore what could have possibly caused it. Were still really confused as to what happened and what to do about it, that competition was our last shot into the world championship and this match had a significant impact on out outcome (assuming we had played that match with connection and that our proceeding matches played out the same way as they did we would have likely been ranked 2 instead of 5, it is impossible to say for sure that this would have happened however it is very likely that a different outcome would have taken place)

Thank you, Robert


The VEX Tech at the field remembers both the Controller and Joystick ROBOT light being red with a brief off-time. This indicates the Cortex has or had a low main battery (red) and that one Joystick is being used (brief off-time).

Your particular robot has an excellent debugging tool. It has the battery voltage displayed on an LCD. The VEX Tech read “BATT VOLTAGE:” “0.0V”. The battery connector going into the Cortex was wiggled. The LCD then indicated “7.82V” or so. The robot came to life and drove for the remainder of the match.

There were no indications the alliance partner was having issues. The field’s Driver Interface sends the same control lines to both teams in the alliance. If the field was commanding your robot incorrectly, it would have also commanded your alliance partner incorrectly and shown an incorrect state on the Driver Interface.

None of the above descriptions indicate a field issue. A loose main battery connection is the likely cause.

To enable field support staff to help, the drive team and robot should be in position, connected and linked ahead of time. This will allow more thorough debugging. Proper connection is indicated by the Cortex and Joystick lights. A full description is in the User Guide. Ideal is a green JOYSTICK light, green ROBOT light and blinking green VEXnet light. The GAME light should blink amber to indicate Disabled, blink green for Autonomous and be solid green for Driver mode. Feel free to ask for verification that your indicators lights are correct.

Rule G7 does not apply here, as that rule deals with a Coach interacting with the team’s controls

Based on what has been described above, there was no reason for the tournament officials to award a replay. Replays are never awarded for Robot failures. In this case head referee consulted with the field tech who determined this was a robot failure, thus no replay was awarded.

In general, if a referee does not award a replay, you can always take your concerns to the Event Partner for their consideration.