On 2013-07-31, Thomas Laus <[email protected]> wrote: > The pulse width wasn't adjustable. It was was just on the ragged edge > of what the Soekris UART DCD was able to see for pps kernel > discipline. It occasonally missed a pulse and that caused some > problems for ntp because it had the time solution from the serial > port data, but not the pps timestamp that matched. > >From the Thunderbolt book:
1 PPS: BNC Connector TTL levels into 50 ohm 10 microseconds-wide pulse with the leading edge synchronized to GPS or UTC within 20 nanoseconds (one sigma) in static, time-only mode. The rising time is <20 nanoseconds and the pulse shape is affected by the distributed capacitance of the interface cable/circuit. My Soekris board could not handle something that narrow. Tom -- Public Keys: PGP KeyID = 0x5F22FDC1 GnuPG KeyID = 0x620836CF _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
