William Unruh <un...@invalid.ca> wrote: > On 2015-02-07, Rob <nom...@example.com> wrote: >> walter.preunin...@gmail.com <walter.preunin...@gmail.com> wrote: >>> Ok, so these questions might be off the wall. >>> >>> Is there any reason why I could not share the PPS output of say, my u-blox >>> 7 GPS module on multiple computers? Would it be good or bad to peer these 2 >>> systems with each other? >> >> We do that in our project to synchronize several systems to the same >> GPSDO accurately. We use surplus "video distribution amplifiers" because >> they neatly fit into this (BNC In/Out, correct levels). There also exist >> dedicated devices for this. > > Actually the biggest problem with this is that it takes time to service > a gps interrupt. Thus the first pps to come in, or be serviced delays > the servicing of the second interrupt. Thus the accuracy of the two GPS > is very ( 10-20usec) different. (I call that "very" because a gps pps is > capable of 1usec accuracy, so a factor of 10 worse is alot)
No, the single PPS is fed to multiple systems that each service the interrupt at the same time. I presume you meant this followup to the "multi PPS sources to a single system" and then it is not true either, of course our systems have at least 4 cores and they can service multiple interrupts at the same time. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
