Re: [Linuxptp-devel] understanding currentUtcOffsetValid
On Sat, Jan 13, 2018 at 09:27:05PM +, Loy, Matthias wrote: > For my understanding if currentUtcOffsetValid is 0, the ptp clock uses > an utc offset currentUtcOffset but is not sure whether this is the > current value issued by the IERS (International Earth Rotation and > Reference Systems Service). If the clock knows the current leap seconds > it gives currentUtcOffsetValid = 1. Yes. > And could you please acknowledge another conclusion I made in may tests > with ptp: No matter whether currentUtcOffsetValid is set or not, > currentUtcOffset is used in both cases to calculate utc from tai. Yes, but with one subtlety. When considering the UTC offset from a foreign master, ptp4l accepts the new offset if one of two conditions is met. 1. The foreign master claims currentUtcOffsetValid and timeTraceable. In this case, we believe the foreign master. 2. The foreign master reports an offset larger than the current one. In this case, we assume at the local node's offset is out of date. HTH, Richard -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
[Linuxptp-devel] understanding currentUtcOffsetValid
Hi, we are not really sure about the meaning of the parameter currentUtcOffsetValid delivered by pmc GET TIME_PROPERTIES_DATA_SET. For my understanding if currentUtcOffsetValid is 0, the ptp clock uses an utc offset currentUtcOffset but is not sure whether this is the current value issued by the IERS (International Earth Rotation and Reference Systems Service). If the clock knows the current leap seconds it gives currentUtcOffsetValid = 1. And could you please acknowledge another conclusion I made in may tests with ptp: No matter whether currentUtcOffsetValid is set or not, currentUtcOffset is used in both cases to calculate utc from tai. thank you very much, Matthias Hottinger Baldwin Messtechnik GmbH, Im Tiefen See 45, 64293 Darmstadt, Germany | www.hbm.com Registered as GmbH (German limited liability corporation) in the commercial register at the local court of Darmstadt, HRB 1147 Company domiciled in Darmstadt | Managing Director: Andreas Huellhorst | Chairman of the board: Eoghan O�Lionaird Als Gesellschaft mit beschraenkter Haftung eingetragen im Handelsregister des Amtsgerichts Darmstadt unter HRB 1147 Sitz der Gesellschaft: Darmstadt | Geschaeftsfuehrung: Andreas Huellhorst | Aufsichtsratsvorsitzender: Eoghan O�Lionaird The information in this email is confidential. It is intended solely for the addressee. If you are not the intended recipient, please let me know and delete this email. Die in dieser E-Mail enthaltene Information ist vertraulich und lediglich fuer den Empfaenger bestimmt. Sollten Sie nicht der eigentliche Empfaenger sein, informieren Sie mich bitte kurz und loeschen diese E-Mail. -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
