increase NUM_NO_REPLY_UNTIL_UNRESPONSIVE to 6

[bdilman]

Solved Problem

To make sure latency or other issues between the FMU and the mission computer do not cause a mode registration problem, number of no replies to raise the mode unresponsive flag is increased to 6. This change is added after observing mission computer latency issues due to overheating and increasing this value relatively increased the chance of successful mode registrations.

Fixes #{Github issue ID}

Solution

• Mode unresponsive flag counter NUM_NO_REPLY_UNTIL_UNRESPONSIVE is increased from 3 to 6.

Changelog Entry

For release notes:

Feature/Bugfix XYZ
New parameter: XYZ_Z
Documentation: Need to clarify page ... / done, read docs.px4.io/...

Alternatives

By enabling mode registration while armed, an unresponsive mode can be re-registered and any undesired mode unresponsive flag can be resolved. Please see, #24249

Test coverage

• Unit/integration test: ...
• Simulation/hardware testing logs: https://review.px4.io/

Context

Related links, screenshot before/after, video

[bkueng]

If you experience timeouts during mode registration, you have to increase NUM_NO_REPLY_UNTIL_UNRESPONSIVE_INIT instead. Did you run into this with a version that includes 4883f21?
Can you provide the relevant app and PX4 output when it happens? Is your app by chance blocking the main thread for a while?
I'm not against increasing if necessary, but want to make sure there's sufficient data to support that.

[bdilman]

If you experience timeouts during mode registration, you have to increase NUM_NO_REPLY_UNTIL_UNRESPONSIVE_INIT instead.
Thank you for the pointer, this is really good to know in case registration issue occur again. I will check archived flight logs to check the registration fail reason from back then (main effective solution was on the hardware side and therefore we can even close this PR draft.

Did you run into this with a version that includes 4883f21?
No, initial change was done while using an older version. I will go through previous logs and update here to be able provide relevant data.