ARENA Fault

[Mark McLeod]

Originally Posted by Dave Flowerday

I will add that the opposite is also true: it's common for event staff and volunteers to blame the teams' equipment, because the field worked fine in the previous match.

I agree too.

That's the first thing I put a stop to when I was asked to Tech the SBPLI field last year-empty speculation by field staff. If the field staff didn't KNOW what the problem was, they were to refer it to me and not start guessing. It's actually harmful in that it usually focuses troubleshooting in exactly the wrong place. I worked the WPA desk one regional where if they had any field connection problems they sent it back to us to be reset, but I never found even one that was set incorrectly. Of course, the robot that caught on fire was plenty obvious...

It worked out well for Long Island last year, but I still had an IT professional telling me it was a field fault that shutdown only his team's drive motors. His explanation was that it couldn't be his code, and to be fair it actually wasn't, but it also wasn't a field failure. It could have been prevented by adding an error check in his code.

[Jimmy Cao]

I understand your frustration with regards to robot(s) losing communication with FMS during matches, but you need to understand a few things.

1) Sometimes, it is genuinely the fault of the robot (or team that fielded the robot). Robots can lose communication with FMS for a variety of reasons, a large number of which result from how the team hooked up their robot. A bad ribbon cable, poor electrical connection, etc. could all cause this. FMS logs will just show a large number (100%) dropped packets for the duration of such events. However, a large number of other events can cause FMS to show 100% dropped packets, hence it is (near) impossible to arrive at a sound conclusion. As much as any of us who've been hit by comm issues doesn't want to admit it, it is very like that the fault isn't in FMS, but its in some aspect of our robot. In the rare situations where FMS did fail, I wholeheartedly trust the people behind the scoring table to diagnose the issue accordingly and act appropriately, but I'm also willing to accept that they can't possibly figure everything out. Remember, our control system consists of a ultraportable PC, a wireless gaming adapter, and an industrial grade controller. Were any 2 of those components really intended to work in unison? No. This leaves plenty of room for small mistakes to cause catastrophic results (consider all the possible issues with the radio's reset button, a plug for the radio that's probably not designed to be shaken as robots collide/cross bumps/etc, and all other potential failure points, these wouldn't be on a system who's sole purpose was to robustly control FRC Robots. They also would probably make the system cost prohibitive).

2) The field crew does its very best to give every team the chance to play; regardless of whether their comm issues are robot-sided or field-sided. Genuine mistakes happen, and the FTA and co. would never intentionally ignore situations in which it is clear that a FMS bug caused robot(s) to lose communication. However, I have yet to see a situation in which FMS causes less than all of the robots on the field to lose communication.

3) The FTAs do their best to diagnose the issue, but understand that they're people too. I know first-hand that the FTA for the TC and Detroit FiM District events will stop at nothing to pinpoint the cause of robots not communicating with the field right. The FTA at Cass Tech was also obviously working extremely hard, as the back of his shirt was clearly covered in sweat. Unfortunately, there were still robots that had comm issues at both events. Nevertheless, it is important to credit the hard work that the FTAs (and FTAAs) do at all the events, since they're the ones working (largely) behind the scenes to make the whole event run smoothly.

4) All that being said, it is crucial that each and every team take all necessary measures to ensure that their robot doesn't become the cause of comm issues. Ensure that all electrical connections (especially those to the radio, cRIO, etc) are secure, especially if you traverse bumps. Ensure your code is robust, as a watchdog bug can (and will) cause a loss of comm, either momentarily or permanently.

5) Remember that FRC competitions are volunteer run. The FTAs are volunteers, the refs are volunteers, the querers are volunteers. If you know a cRIO/controls/something expert who's willing to volunteer at the events to look at robots who've had communication issues, then invite them to offer their help. Otherwise, other teams are more than willing to provide any assistance they can. If you're continuously having comm problems, ask the FTA if you can try to sync to the field after the end of matches on Friday (or maybe even at lunch).

I guess that's all I have to contribute...

[Big Kid]

To take a shot in the dark here, there has been a major problem on the Driver Stations this year. There has been problems of the Joysticks saying that they are connected but not responding, most times the I/O board will be attached to the hub and be draining too much current for everything connected to the hub to remain operational. There have been some cases where it has happened with just joysticks connected to the hub, there's been multiple solutions thrown out there to be tested to solve the problem. Now, relating to your particular situation there is a chase that it was a field problem, it plausible, but by some chance it is also probable that this lack of Joystick response to the Classmate is the culprit, and this problem does not appear on the log.

[BEEKMAN]

Originally Posted by kylelanman

ARENA as it is defined in the rules.

The ARENA includes all elements of the game infrastructure that are required to play Breakaway: the FIELD, the ALLIANCE STATIONS, the GOALS, the BALLS, and all supporting communications, arena control, and scorekeeping equipment.

The only rule I see regarding ARENA faults.

<T18> If, in the judgment of the Head Referee, an “ARENA fault” occurs that affects either the play or the outcome of the MATCH, the MATCH will be replayed. Example ARENA faults include broken field elements, power failure to a portion of the field, improper activation of the field control system, errors by field personnel, etc.

A common response that I have heard is "After reviewing the log of the entire match nothing seems out the ordinary so the match will not be replayed". How is 1 to 4 robots loosing coms not something wrong? Something is clearly wrong. Thousands of fans can tell with out looking at a log that something went wrong.

Outside of FIRST when someone has an IT related problem and it can not be identified from the log we don't tell the person(s) they are out of luck and we aren't going to help them. The IT department looks into the problem and rectifies the situation as soon as possible.

The least they could do is have a professional on site at each regional to inspect the robot after the match back in the pit and help figure out what is wrong. How can a bunch of high-schoolers be expected to find the problem when the inspectors at the event can't. From the looks and sounds of it the only reason that help is not offered is that no one actually knows what causes all the comm problems.

If FIRST can not help us troubleshoot the mysterious comm problems that never happen at the shop but randomly happen on the field then teams should be given the benefit of the doubt and the match should be replayed when they occurr.

Goood point...bad logic. Often it is infact the fault of the Team, and an issue with the Robot. ex) We lost a match because when we went over a bump, one of our power cables (only for a split second) would come loose, causing our cRio to re-boot. After 30 mins of testing, we figured it out. At a glance, and even in depth, it appears to be an FMS problem, when in actuality, it isnt.

Another common problem is voltage drops. if hte voltage of your robot drops below 10, ther is a chance your wireless link will reboot itself.....causing comm issues.;

The FMS log will show al this.

The ONLY time in teh two regionals that I saw an Arena Fault (we decided it wasnt worth it to call it, and have teh match redone) was when Autonomous mode started, and 2 seconds later, thye game was disabled, only to become re-started at the START of autonomous mode again. This caused problems with teams' autonomous mode, as they had already driven a little before the second auto mode begining (causing them to miuss baslls due to improper spacing).