Dave, Yes, the driver appears to walk-through several old TrueTime devices, some of which I don't think are even functional these days. The 468DC GOES receiver will not work (GOES stopped transmitting time back in 05 I think) unless you use a special antenna that converts a GPS signal into something the unit can read. But that's another story.
One of the reasons the driver did not work for me was the code is too generic when checking for a TrueTime device. It just assumes anything with a string "TRUETIME Mk III" is a GPS model and sends a F50 & F51 code to get some GPS specific satellite info. Since those codes are specific to GPS models only, my receiver sends back a "ERROR 05 NO SUCH FUNCTION" which throws the code into a different state making it impossible to proceed with the time-output. Those two codes that are sent (F50 & F51) are never checked against anything in the code to ensure satellite validity and such, I guess the somebody started the implementation but never got around to finishing it. I was hoping someone with a GPS model would be able to post their version string and see if it was different from mine, also it would be nice to get the GPS info to complete those checks. A little less elaborate method could be used by assuming if the Truetime string passes, but the F50 & F51 strings fail then it has to be a IRIG or PPS model. Or the whole F50 & F51 strings could be skipped entirely since they don't actually do anything. I noticed too if I first start the once-a-second time output from the NTS serial port then start NTP, it works just fine. The debug shows it stops at the first receiver check (Omega I believe) and since it's receiving time in a format it can parse (just falls through the code until the time parse routine) it is happy. Anyhow, I'm not complaining or anything, the whole experience of communicating through the NTS serial port was just a "for fun" experiment. Anyone using this method would have to adjust their offset slightly, but the jitter is quite reasonable. In the end though, it's not really a practical means of a time source for the NTS series since they have a built-in NTP server and even a PPS output. Jason > I recall that Paul Vixie was the author of that much-mangled driver. He > intended to support a number of TrueTime devices, including the GOES and > WWVB clocks which are no longer manufactured. The code has little > wiggles designed to support most if not all historic TrueTime devices > with one driver. Should you make serious changes to adapt your a model > not supported by the driver, it might lose the valuable feature of one > driver fits all. > > TrueTime of course has been eaten by Symmetricom and it appears all > except the GPS receivers have become extinct except on eBay. What I'm > saying is that it might be better to clone another driver and leave the > TrueTime one alone. The best choice would be to find a driver that with > minimal compile or configuration changes could support both the original > and your driver. Several drivers now automatically detect which radio is > hot and configure accordingly. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
