Chief Delphi - FMS Differences with motor safety?

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Re: FMS Differences with motor safety?

I think the output of the motor safety warnings is a symptom, not the problem. It is my belief that the WPIlib has some issues, I'm thinking in the NetworkTables implementation, where it will stall a thread, keeping it from being able to update the motor controls.

In our "lab" using a practice robot, I would notice that at times the robot would become unresponsive. A few seconds later, the motor safety helper message would start on the console. I could close the SmartDashboard application, an error would appear on NetConsole and immediately the robot would recover and the messages would stop. Without SmartDashboard there was no such problem.

At our last regional (Knoxville), it was STRONGLY SUGGESTED that we install the latest version of the Driver Station software on our laptop. As soon as we did so, we started having control issues and motor safety helper warnings, even with no SmartDashboard application running.

By this time, I had put #if/#endif pairs around all of our SmartDashboard code, and we decided to disable them at the competition, but also to switch to another laptop still running the slightly older version of the Driver Station for competition as we were unable to get back on the practice field to test out the changes with the new version of the Driver Station.

Re: FMS Differences with motor safety?

The difference between the earlier 2013 and latest 2013 DS release are very minor. It is related to logging of robot data to your DS computer. None of it interacts with smart dashboard.

As with the FMS interaction, I'm providing this info so that you can look for the issue where it is most likely occurring. I cannot guarantee anything 100%, but I can tell you that in my opinion, the new DS has nothing to do with your issue and neither does the FMS.

Greg McKaskle

Re: FMS Differences with motor safety?

Quote:

Originally Posted by JefferMC (Post 1256751)

In our "lab" using a practice robot, I would notice that at times the robot would become unresponsive. A few seconds later, the motor safety helper message would start on the console. I could close the SmartDashboard application, an error would appear on NetConsole and immediately the robot would recover and the messages would stop. Without SmartDashboard there was no such problem.

Yeah, there seem to be a lot of suspicious reports involving the SmartDashboard; I heard from a team or two at our regional that had to remove it to get a stable operation, and I recall seeing threads here that pointed suspicious fingers at it as well.

Cheers,

Jeremy

Re: FMS Differences with motor safety?

Quote:

Originally Posted by jwhite (Post 1256084)

I hope to run a test to see if generating error messages at the same time Network Tables traffic is being sent can cause a crash; that would test my first hunch. The other step I would take is to put wireshark on while it operates to see if that generates any further clues.

Just for completeness, we did run this test, and got no crashes. I also pulled a wireshark trace of our exaggerated test (which sent a lot of Network table updates), and didn't find anything that jumped out at me. Ah well, color me stumped.

Cheers,

Jeremy