[ntp:questions] NTP sever on an isolated Network

Unruh unruh-spam at physics.ubc.ca
Fri Jan 9 17:43:14 UTC 2009


leituras at gmail.com (Diego Ramos) writes:

>> Why not sell your old USR modem to you work. Or donate it.


>I've just donate it. hehe

>What is teh necessary precision you need? If it is a few msec a modem is
>> fine. If it is micro seconds then use GPS.
>>

>msec is perfect because I just need video frame precision. But I'll request
>a GPS anyway.

>All of them have an antenna. Just buy the Garmin GPS18LVC wire it up to an
>> extention line ( eg a Cat 5 network cable) of the length you need. If that
>> length is longer than about 100m you need to terminate it properly and
>> probably put an impedance matching amplifier on the computer end of it.
>>

>All right, but what is LVC? Where I'll connect it in my computer?

It is part of the model name. It comes with bare wires. YOu have to solder
connectors onto the wires. The most common is to drive the unit from the 5V
from USB and feed the output into a serial port.  There are a number of
places on the web that will take you through the process.


>The standard is the Garmin GPS 18 LVC . NOT the USB or the PC version --
>> they are completely useless for time. Only thge LVC is useful for time.
>> (or the LVCX now I believe)
>>
>> It is about $100.
>> Note that you really only need one and can use the computer it is attached
>> to as a server which can -- depeding on your switches on your internal
>> ethernet, give you 20microsec resolution for the time on other system
>> conencted to it.
>>
>>
>I've already got the budget to buy one for development. Thanks for the
>indication.




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