yet another connection issue thread

[mobilegamer999]

Hello, I'm not sure how much detail i can give about this but our team had gone to two district events located at Traverse city and at GVSU. At both events we had no communication issues at all. As soon as we got to our state competition we got our robot all set up with no changes made to the bot at all. After the bot was un-bagged we got it inspected and immediately brought it out to the practice matches to make sure everything was running smoothly and we went through the whole match without any problems. When we got to our first match which was all of about an hour later with, again, no changes made to the robot, while in queue for the match we always pre-charge our tanks and before this match we plugged in with a cable to a laptop and without any issues brought our tanks up to 120 PSI then turned the bot off and plugged in our radio again. As soon as we brought our bot out to the field and it connected to FMS, our communications light was going in and out, it only stayed on for about 1 second and was out for about a second. We could intermittently control th robot while the light was on but it was going in and out for the whole match, halfway through the match i even tried remotely rebooting the cRio to no avail. As soon as the match ended we approached the FTA and asked if it was a possibility of a field error but they said no. As soon as we got back to our pit we inspected every possible connection but nothing came up as a possible issue. We then went out to our second match and the issue during this match was slightly different, what happened was mid match our cRio rebooted twice but had full communication between reboots. We assumed a power issue so we sured up all possible connections on the PDB and cRio main connector, we also borrowed a radio from pit admin and put it in our bot (before you ask, were using the older radios, the ones that are better). During the third match we had full communications for the entire match so we assumed we had fixed the problem. In our 4th match we had the same issue as match 1 where we went in and out of comms, we did not give thumbs up at beginning of the match and they told us there was nothing we could do and that we had to play the match. Between matches we went to pit admin and borrowed a cRio from them and we put that in the robot with no issues next match or any further matches. We believe it to be an issue with the cRio but we are not 100% sure because even in the matches with bad comms we were still able to pre-charge our tanks by tethering up with the net-book.

[Greg McKaskle]

When you say "our communications light was going in and out" I assume you mean the overall Communications status light on the left was blinking off and on. Did you go to the Diagnostics page to see if there were errors or what the other LEDs showed? The Communications LED indicates that the overall system is working. The other LEDs represent lower and lower levels and would hopefully indicate what was failing.

When you say "our cRio rebooted twice but had full communication between reboots", that cannot mean the Communications light was on. What does that refer to?

Hopefully this will not happen again, but here are a few observations that may help. If the robot stops communicating but the RSL is still on, the cRIO is still on and it is usually the radio that lost power or connection. If the connection comes back 30 of 40 seconds later, it is probably the power to the radio. If the connection comes back 15 to 20 seconds later, that is the boot time of the cRIO, so check the power there.

Finally, I didn't hear you say anything about ethernet cables. You may want to observe the lights while wiggling the enet cables, particularly around the connectors. Also make sure your bridge isn't buried in the robot so that the antennae is blocked.

Greg McKaskle

[yarden.saa]

We had the same problem. The solution is to give the robot time without electricity. It happened us in the night and we were trying to solve the problem without success for about 4 hours. It was late so we went home and the next day it worked. It happened us 2 times.