Packet Loss investigation

At our last off season event, our controls were sluggish. I started by looking at our driver station logs and notice that we commonly had 10-15% packet loss. Here’s an example of one match. How much packet loss can wpilib handle before impacting robot performance? Additionally what else should I look at for more clues to our issue. Is it common for there to be packet loss?

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Do you happen to have Autodesk inventor installed on that system. It causes behavior like that.

No, we’re using onshape, and it’s our dedicated driveteam laptop.

Our Day 2 was better. Since we had a limited team due to covid, I wasn’t there. I’m trying to piece the puzzle back together. I’m trying to determine when any code changes were made. This was one of the ‘worst’ matches from day 2. It’s a lot better than day 1.

Not a solution but a side note: clumsy, an utility for simulating broken network for Windows Vista / Windows 7 and above
Use ^ with some lag and 2% packet loss to help simulate some tough on field conditions for ur driver in your shop.

Credit: @kf

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What happens when you replace the Ethernet cable between the radio and roborio with a new one, not just a different one, but a new one ?

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We can give that a try this weekend.

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Could you explain more as to how Inventor would cause packet loss? Is it only when Inventor is running? Is it even while not running?

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It’s the Autodesk background updater which causes the issue, so it happens even when Inventor is not running. The updater is doing network requests that can cause packet latency spikes.

EDIT: above post has good relevant CD links

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Particularly if you are streaming video at too high a rate, or doing a whole lot of print debug, it’s possible drops happen because there is too much traffic.

It’s also possible drops happen because of poor network connections or interference. One thing that can happen is having the radio surrounded by metal, or too close to a noisy motor or other electronics.

In your case, figuring out what changed between days one and two is going to be a really helpful clue.

I pinged other teams at the competition and one responded that they also had lag issues on day 1. I’m leaning towards an issue that’s outside of our bot.

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