View Single Post
  #9   Spotlight this post!  
Unread 24-04-2015, 17:44
scca229 scca229 is offline
FTA acquiring knowledge
AKA: Nate
FRC #0060
Team Role: Mentor
 
Join Date: Apr 2014
Rookie Year: 2011
Location: South of Phoenix, Arizona
Posts: 213
scca229 has a spectacular aura aboutscca229 has a spectacular aura about
Re: Carver Connection Issues?

Quote:
Originally Posted by dodar View Post
The Pink team's last match they died and then came back.
What is "died and then came back"?

Possibilities I can come up with for just on the robot itself:
  • Battery cable loose at Anderson briefly disconnecting causing full robot reboot?
  • Battery cable loose at main breaker briefly disconnecting causing full robot reboot?
  • Battery cable loose at battery briefly disconnecting causing full robot reboot?
  • Battery cable loose at PDB briefly disconnecting causing full robot reboot?
  • roboRIO power cable loose at PDB causing brief disconnect rebooting roboRIO?
  • roboRIO power cable loose at roboRIO end causing brief disconnect resulting in roboRIO reboot?
  • Red fuse not fully seated in PDB causing brief disconnect and roboRIO reboot?
  • Yellow fuse not fully seated in PDB causing brief disconnect and radio reboot?
  • Radio power cable loose/stray strands at VRM causing brief disconnect and radio reboot?
  • Radio power cable at radio causing brief disconnect and radio reboot?
  • Ethernet cable not fully inserted in roboRIO causing brief disconnect and reattach?
  • Ethernet cable not fully inserted in radio causing brief disconnect and reattach?

The above is only considering components that the robot HAS to have to pass inspection (and I'm probably missing some). I have no clue of any additional stuff on that particular robot to troubleshoot since I don't know what other components are on it. Each of the above issues can be narrowed down based on how long it was out of commission. 10 seconds or so is probably a radio power issue. 40 seconds is a typical roboRIO reboot. 3 or 4 seconds might be the ethernet cable.

As an FTAA, when I see a bot stop moving or the connection monitor shows a red box somewhere on their line, I make a quick assessment of what I can see via status lights (THANK YOU teams that mount the roboRIO & radio in easily visible locations) and what body motions the team is making behind the glass (do they look confused?). I look at the radio and see if the status light is red, indicative of a reboot and power issue and I look for the roboRIO to see what it shows. When the radio goes to 2 blue lights, if the bot doesn't move fairly quickly, then the lights on the roboRIO will tell if it is booting as well. That narrows down whether the whole bot lost power, or only a part of it so that I can notify the team and/or RI/CSA to help them out.

Possible causes on the DS Laptop are spelled out earlier in the thread along with quite a few more that I'm not able articulate in the few minutes I took to type this out.

Did the RSL stop blinking when the "died and then came back" occurred? How long was the "non-motion" period? Was the "non-motion" intentional? On bots that the teams have mounted the RSL is a location visible from all around (yes, I know the Robot Manual only says from the front...wish they'd change that), I can easier tell if the non-motion is due to the robot not receiving from the DS. If it is flashing, I'll stay put but keep a closer eye on it until they move again.

I'm not saying that the FMS can't ever be the cause of an issue, but the vast majority of the time, the cause is able to be traced to something on the robot or on the DS laptop. Normally when the FMS is involved in the problem, an entire alliance or both alliances experience the problem as they are sharing the same Layer 1 resource, albeit in their own logical sandbox.


Any additional info on what the "died and then came back" issue was?
__________________
Nate

Last edited by scca229 : 24-04-2015 at 17:46.