Using NTP protocol for internal time synchronisation

ntpntpdtime-synchronization

I have two embedded system that are connected via ethernet. I want them to run synchronously. Using NTP protocol is an option to synchronize them. But this is a isolated system. I don't have an Internet connection. Is it possible to use ntp protocol locally. One of my system will be the master and the other one will be slave.

Kind regards…

Best Answer

Yes. You need a NTP server on the local LAN. There's two things here - accurate time (e.g. the time is actually correct) and time sync (they all have the same time, whether correct or not).

If you just need the systems to simply be in sync, to agree on what the time is even if they're not using the correct time, you can just install a cheap box with your favourite Linux distro, configure it to act as a time server (example) and tell both these embedded systems to use that as their time source.

If you need accurate time then you need a GPS or radio time clock, which will set time to an external source without needing an Ethernet connection. This is the one I use, for example, but there are others out there.