05-25-2010 10:48 AM
Been tangling with this problem: I have two PC-based data sources whose clocks I'd like to keep synchronized within ~25ms. They share an ethernet x-over connection on static IPs. Machine A is my deployment target, Machine B is a device controller that I have essentially user access to. Both are Windows XP PCs. No net connection exists. The two machines are only connected when my software is in use. Tests run ~1hr max.
I tried using the Windows Time Service ( w32tm and W32Time ) to synchronize two XP machines. I followed this MS article on how to configure xp as an NTP time server, and set the client up to sync from it. http://support.microsoft.com/kb/314054/. I got it working and got it to correct a 16second difference between the machines, but it doesn't seem to do anything if there's an offset under 1sec. in http://support.microsoft.com/kb/939322best , MS claims that 1-2sec is the limit of the software.
Has anyone used a different NTP setup? I see a few posts involving NTP and cRIO, is there any application of that here?
05-25-2010 10:57 AM
Do you need to sync them WITHOUT a network connection?
If you have a network, you could use UDP to transmit sync packets after you benchmark the transport time.
Otherwsie IRIG-B interfaces (don't remeber the NI borad that supports it) will let you sync to the GPS clocks.
Ben
05-25-2010 11:26 AM
Hi blawson,
Have a look at www.arachnoid.com/abouttime/
It has a program that can be a network time server or client. That may do what you need
Rod.
05-25-2010 11:46 AM
-sorry if it wasn't clear enough: computers are networked peer-to-peer with no internet connection.
though W32Time is trying to *keep* computers synchronized, all I want to do is force one computer to sync off another on command.
I've discovered that with the proper network sharing setup, "net time \\computername /set /yes" on a command line will do what I want.