V5 Field Control "Legacy Field Control Detected" and "Wrong controller radio firmware: 0"

I’m running an event today and getting errors with the V5 field control - teams are showing up as “Legacy Field Control Detected” and not communicating with the field - the teams aren’t disabling / running autonomous correctly.

We also had one of the teams show up as 'Wrong controller radio firmware: 0" despite their controller radio being up to date, and their robot never enabled.

We did not have issues at previous events, and the team mentioned they just bought new controllers. We’ve been swapping them out with controllers we own, but don’t have enough to help all of the teams who recently bough new controllers. VEXos versions and TM versions are up to date all around.

I’ve tried different cables and ports on the field control brain, and it always follows the specific teams with the issue.

What settings did you use for your V5 Field Control app?

Had some issues at an event end of October - I did not set up the V5 Brains for the event, but that may be a possible cause.

Second thing we had was a broken smart cable at the field at one of the alliance station.

It might help to get a snap shot of the team configuration from the V5 Brain running the field when the error occurs.

That’s usually caused by a damaged RJ45 legacy competition connector on the controller.


Can you guys update your documentation to mention things like this? The TM user guide hasn’t been updated since before the new field control was released, and other than the forums there’s absolutely nothing for EPs to deal with issues like this.

It’s not a damaged RJ45 port since the controller is brand new. We connected them to a legacy field controller and it worked fine in match.


There is a KB article on smart field controllers:


and the user manual is here.


I read the entire manual and neither of the errors I listed are in the manual.

It depends on what was wrong, for example, if the pin that is used to detect competition switch/legacy field control is damaged, the comp switch would still work but the new system would still detect it as damaged.


The controller is brand new and 2 of them are doing this The port is visibly fine. We’re also seeing a controller radio firmware: 0 issue for another brand new controller, despite the radio firmware being correct.

Well, one is.


I checked the legacy port, it’s physically fine, no bent pins, and there is no competition switch connected. The teams with issues have said they all bought new controllers since our last league event (where we had no field control issues). I can’t keep digging through my bins for used controllers to give to teams when the new ones won’t talk to the field.

I assume you have latest FC application which is 1.0.3b2

It’s a bit difficult to debug remotely, not sure what to suggest while the event is running.
Teams should be on vexos 1.1.2, controller radio should have been updated if it was tethered to the brain, but generally there’s no easy way for a customer to absolutely confirm controller radio is up to date.

legacy port can be damaged if a smart cable was plugged in accidentally, there will be no physical damage but internal circuit may have been affected.


I agree, it’s frustrating for me too, trying to troubleshoot an error with no documentation. The field control shows the controller radio version as 0 (which shouldn’t be a valid version), but the brain shows the controller has the latest firmware. It seems like a communication issue, but I’d expect there’s some sort of data integrity checking on the RS485 bus and I can move ports around on the FC brain and it tracks the controller, not the cable or the brain port.

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I think there was a discussion about overriding Legacy Port issues if smart field control used? Or did I dream that :slight_smile:

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if the message is only on the FC brain display, just ignore it, I’ll check on Monday why that may display, I know we started ignoring it during worlds.

The problem is that smart field control may not work correctly if the legacy port is damaged. Usually you can also detect this as the controller will show it’s under competition control on the display, the small pause/auton/drive icon, all the time, even when disconnected from all types of field control or competition switch.


I didn’t find any way to override the legacy port issues in TM.

It also seems like I have 5 dead ports on the FC brain, and another one might be dying, causing some of these issues (ports 1,3,4,5 are dead, and 2 might be, so no more Red 1). But there are still two teams’ controllers that are showing errors on any port / cable, separately. The controllers with radio errors showed a connection radio → brain, but did not enable during the match and we reset/re-ran the match

The message is in TM, not just the FC brain display.

That was more a question for James for future planning.

Out of curiosity - Were any of the problems with two V5 Controller configurations (teams using two controllers?)

Not fun when technical issues rear happen event day.

None of the teams at the event are running two controllers, so I can’t say.

I swapped out the FC brain, and we also have the legacy towers, but a lot of the legacy parts I have are dying as well and I didn’t replace them, thinking the new system would work. It’s our second league event with the same teams and we had no issues during the first session at all.

After swapping out the FC brain it seems like partially dead ports will result in errant data - is there no data integrity checking on the RS485 bus? The death rate on ports is getting out of hand, this is the second FC brain I have with a bank of 5 dead ports.

In addition to that we never resolved the wrong controller radio firmware issue for 2 of our teams, and those teams did not work correctly in match. We had them use the legacy vexnet controls. They were on the latest VEXos and had tethered to update the controller firmware.

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