cnoyes2 wrote:
I'm trying to sync the time on 2 Windows XP computers that are not on
the internet and never will be. For testing purposes, they need to
have the same time. The time does not need to be accurate. What's the
simplest way to sync these computers?

I've done a lot of searching, but can't seem to find much about
computers not attached to the internet.

I've tried net time \\computer_ip /set /yes, but I get an access
denied error.

Thanks in advance.

How close do the two clocks have to be? It's fairly easy to get two computers to agree within five or ten seconds with no special equipment or software required. If you need to be within five or ten milliseconds it starts getting difficult and possibly expensive. If you need to be within five or ten microseconds it can still be done but it will take some fairly expensive equipment.

The easiest thing to do if you can site an antenna where it will have an unobstructed view of the sky, is to purchase a "hardware reference clock". The cheapest goes for about $100 US. It's called a GPS18-LVC if memory serves me. If my memory fails me I'm sure someone will be delighted to point it out! ;-)

The GPS18-LVC and other similar devices, get time from the NAVSTAR (GPS) satellites. The antenna is generally smaller than a hockey puck. I have mine on top of a "Leaf Guard" rain gutter. They have a Pulse Per Second (PPS) output. One edge of the pulse is generally within 50 nanoseconds of the true time. There is also an RS232C serial output that tells you which second the pulse is marking.

NTPD has drivers for a number of different devices. In addition to GPS satellites there are VLF and HF broadcasts provided by the National Institute of Standards and Technology (NIST) in the US. Other countries also provide radio time signals.

_______________________________________________
questions mailing list
questions@lists.ntp.org
http://lists.ntp.org/listinfo/questions

Reply via email to