F-35 radar system has bug that requires hard reboot in flight

Re:F-35 radar system has bug that requires hard reboot in fl... by luch on Thursday March 10, 2016 @02:55PM (#11261786)

That is one explanation. I've worked in avionics telemetry & remote sensor fusion and there is actually a push to go from synchronous archs (using PCM on I2C buses) towards modular and networked archs (using some variant of IP/etc. protocols).

Problem is you need a reference time clock. On monolithic arch, is easy : the backbone bus timestamp the paquets it sees. On networked arch you need a time server a la NTP, otherwise you have time skew and loopbacks.

Even with a accurate time clock, you may also need to correct for timing issues due to cable length.

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Re:F-35 radar system has bug that requires hard reboot in fl... by mbell on Thursday March 10, 2016 @08:35PM (#11264056)

I'm curious what you mean by 'synchronous' here, for example an I2C bus is clocked by the master, ignoring clock stretching and that clock need not be in any way synchronous with the processor clock on the slave.

And to clarify, we're talking about PHY level protocol clocks here, not time clocks.

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Re:F-35 radar system has bug that requires hard reboot in fl... by jasonwatkinspdx on Thursday March 10, 2016 @03:27PM (#11262006)

Check out PTP, and then the WhiteRabbit research project. It's not exactly easy to implement, but you can get down to ~10ns sync on an ethernet network using it.

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