On Mon, 30 Aug 2010 21:42:33 -0500
Bill Hawkins b...@iaxs.net wrote:
This is not a challenging application for time accuracy, unless a human
(like the CIO) wants to have better accuracy than his (it's a testosterone
thing) competition. Process valves have a 1 second time constant, for the
Hal's response was quite complete, but he missed one essential and
often missed parameter. Redundency.
I have been working for years in operating system support for major
international computer constructors and it amazes me how often I came
across equally large international clients who had no
In message 4c7cc2f1.3060...@orange.fr, mike cook writes:
of references about how to do this in a belt and braces manner. How far
you go (5 independent clocks should be sufficient) depends on how much
your downtime costs.
Let me just add a bit of caution here: The NTP software gets confused
if
You wrote:
Let me just add a bit of caution here: The NTP software gets confused
if it has too many servers to select from.
I would _never_ advice configuring more than 5 ntp servers for any
machine, unless some of them deliberately are made unavailable and
only used for
In message 201008310920.o7v9kzui025...@stenn.ntp.org, Harlan Stenn writes:
You wrote:
I would _never_ advice configuring more than 5 ntp servers for any
machine, unless some of them deliberately are made unavailable and
only used for monitoring/sanity-check.
Sounds like a bug to me.
It is.
You wrote:
In message 201008310920.o7v9kzui025...@stenn.ntp.org, Harlan Stenn writes:
You wrote:
I would _never_ advice configuring more than 5 ntp servers for any
machine, unless some of them deliberately are made unavailable and
only used for monitoring/sanity-check.
Sounds like a
In message 201008310942.o7v9gerf025...@stenn.ntp.org, Harlan Stenn writes:
You wrote:
The problem is that if multiple servers with roughly identical
performance survive the culling, the clock selection codes
commitment-anxiety makes i switch partner far too often.
If you allow the automatic
b...@iaxs.net said:
I'm involved with time synchronization of control system computers for
multi-national businesses. GPS springs to mind as a way to synchronize time
anywhere. Or is it? What about monsoon rains?
The Internet is available almost everywhere that control computers are used,
Hal,
Many thanks for taking the time for that excellent reply.
A true data diode has no leakage. You can make one by clipping the receive
wires in a switch. The control network sends predictable UDP messages with
its data. No concern is taken for harm from the Internet, and it is not
possible to
I'm involved with time synchronization of control system
computers for multi-national businesses. GPS springs to
mind as a way to synchronize time anywhere. Or is it?
What about monsoon rains?
The Internet is available almost everywhere that control
computers are used, but many users prefer to
On 08/29/2010 01:31 AM, Bill Hawkins wrote:
I'm involved with time synchronization of control system
computers for multi-national businesses. GPS springs to
mind as a way to synchronize time anywhere. Or is it?
What about monsoon rains?
The Internet is available almost everywhere that control
I read its hard to get a position fix over the poles of the earth - its
related to the orbits of the GPS satellites. But to get time, you
really only need one satellite.
On 8/28/2010 6:31 PM, Bill Hawkins wrote:
I'm involved with time synchronization of control system
computers for
Bill Hawkins wrote:
I'm involved with time synchronization of control system
computers for multi-national businesses. GPS springs to
mind as a way to synchronize time anywhere. Or is it?
It is, and you can buy boxes from Symmetricom (among others) to do
exactly what you need. The typical box
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