Driver Help? - NTP

This is a discussion on Driver Help? - NTP ; > From: "Richard B. Gilbert" > Date: Wed, 13 Jun 2007 16:15:33 -0400 > Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org > > Kevin Oberman wrote: > >>From: Karl Denninger > >>Date: Wed, 13 Jun 2007 12:07:22 -0500 > >>Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org > >> > >>Steve ...

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Thread: Driver Help?

  1. Re: Driver Help?

    > From: "Richard B. Gilbert"
    > Date: Wed, 13 Jun 2007 16:15:33 -0400
    > Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org
    >
    > Kevin Oberman wrote:
    > >>From: Karl Denninger
    > >>Date: Wed, 13 Jun 2007 12:07:22 -0500
    > >>Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org
    > >>
    > >>Steve Kostecke wrote:
    > >>
    > >>>On 2007-06-13, Karl Denninger wrote:
    > >>>
    > >>>
    > >>>>If Multitech can't get me something better than what I have I may try

    >
    > >
    > > Carl,
    > >
    > > We use CDMA and can keep time within a couple of microseconds. I am using
    > > an EndRun Technologies CDMA clock which provides PPS, but the jitter on
    > > the raw (TrueTime emulated) once a second update is about 4 ms at
    > > worst. This sucks compared to the PPS, but should be good for most cases
    > > where high precision is not an issue.
    > >
    > > By the way, the external CDMA clock from EndRun is pretty well hidden on
    > > the web pages under "Other Products". It is found at:
    > > http://www.endruntechnologies.com/ne...ime-source.htm
    > >

    >
    > They say "Email or call us for a competitive price quote...."
    > Why do I always get nervous when someone says that? It generally means
    > "all the traffic will bear and then some!" I much prefer to deal with
    > someone who says, up front, "it's $1253.99 plus shipping from. . . ."
    > It saves us both a bit of time because there's no way I'm going to pay
    > that much. It might be different if I had a corporate sponsor but
    > nowadays it's strictly out of my pocket!


    Hmm. Since I called them before I visited the web page, I didn't notice
    that.

    In any case, they ran about $1100 when we bought our last batch last
    year. Work very well and will emulate several different types of clock
    including TrueTime, Spectacom, and Trimble Palisade.

    We have about a dozen scattered around the country.
    --
    R. Kevin Oberman, Network Engineer
    Energy Sciences Network (ESnet)
    Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
    E-mail: oberman@es.net Phone: +1 510 486-8634
    Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751

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  2. Re: Driver Help?

    Steve Kostecke wrote:
    > On 2007-06-13, Karl Denninger wrote:
    >
    >> Give me a break. A GPS receiver is a hell of a lot less expensive.
    >>
    >> Competitive my tailfeathers.

    >
    > There are some applications where GPS won't work (due to antenna siting
    > restrictions); CDMA may be the best solution in those cases.


    True.

    But that pricing is simple rape. The Multitech modem, which inherently
    has the same capability (all CDMA devices must) can be had for under $300.

    Reasonable? I think not.

    --
    Karl Denninger (karl@denninger.net)
    http://www.denninger.net

  3. Re: Driver Help?

    > From: Karl Denninger
    > Date: Wed, 13 Jun 2007 18:37:43 -0500
    > Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org
    >
    > Steve Kostecke wrote:
    > > On 2007-06-13, Karl Denninger wrote:
    > >
    > >> Give me a break. A GPS receiver is a hell of a lot less expensive.
    > >>
    > >> Competitive my tailfeathers.

    > >
    > > There are some applications where GPS won't work (due to antenna siting
    > > restrictions); CDMA may be the best solution in those cases.

    >
    > True.
    >
    > But that pricing is simple rape. The Multitech modem, which inherently
    > has the same capability (all CDMA devices must) can be had for under $300.
    >
    > Reasonable? I think not.


    Maybe or maybe not.

    If you want time that is accurate to within 10 microseconds, you need a
    bit more than just a CDMA modem with a serial connection. You need a
    reliably accurate clocking with a very stable internal clock to maintain
    this level of accuracy.

    The EndRun is a simple to connect device with power supply. When you
    need installation by POP techs, simple is critical. And the cost of
    integrating the MultiTech into a small, cheap server in fairly small
    numbers (about 6/year) would probably end up costing more than we pay
    for the EndRun units.

    If a $300 device can do the job in terms of accuracy and practical
    installation, I'm all for it, but the MultiTech does not seem to fit
    that bill. If it fits yours, it would be crazy to spend more.
    --
    R. Kevin Oberman, Network Engineer
    Energy Sciences Network (ESnet)
    Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
    E-mail: oberman@es.net Phone: +1 510 486-8634
    Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751

    _______________________________________________
    questions mailing list
    questions@lists.ntp.isc.org
    https://lists.ntp.isc.org/mailman/listinfo/questions
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  4. Re: Driver Help?

    Kevin Oberman wrote:
    >> From: Karl Denninger
    >> Date: Wed, 13 Jun 2007 18:37:43 -0500
    >> Sender: questions-bounces+oberman=es.net@lists.ntp.isc.org
    >>
    >> Steve Kostecke wrote:
    >>> On 2007-06-13, Karl Denninger wrote:
    >>>
    >>>> Give me a break. A GPS receiver is a hell of a lot less expensive.
    >>>>
    >>>> Competitive my tailfeathers.
    >>> There are some applications where GPS won't work (due to antenna siting
    >>> restrictions); CDMA may be the best solution in those cases.

    >> True.
    >>
    >> But that pricing is simple rape. The Multitech modem, which inherently
    >> has the same capability (all CDMA devices must) can be had for under $300.
    >>
    >> Reasonable? I think not.

    >
    > Maybe or maybe not.
    >
    > If you want time that is accurate to within 10 microseconds, you need a
    > bit more than just a CDMA modem with a serial connection. You need a
    > reliably accurate clocking with a very stable internal clock to maintain
    > this level of accuracy.
    >
    > The EndRun is a simple to connect device with power supply. When you
    > need installation by POP techs, simple is critical. And the cost of
    > integrating the MultiTech into a small, cheap server in fairly small
    > numbers (about 6/year) would probably end up costing more than we pay
    > for the EndRun units.
    >
    > If a $300 device can do the job in terms of accuracy and practical
    > installation, I'm all for it, but the MultiTech does not seem to fit
    > that bill. If it fits yours, it would be crazy to spend more.


    Maybe. I guess much will depend on how much work this ends up being, or
    whether it can be done at all.

    If Multitech comes back with something productive in the way of support,
    then its pretty easy (e.g. a firmware change that gives me a "spit on
    second mark" option)

    This is not all that far-fetched, as they already have several deferred
    commands in the modem that come back asynchronously - its a matter of
    them wanting to do it as opposed to being able to do it.

    And they DO have control of the modem control signals of course, so PPS
    isn't impossible either, although that might be a bridge too far.

    I guess we'll see...... I may abandon this if I can't get Multitech to
    get involved in it, or I may see if I can get it to work without their
    "help".

    --
    Karl Denninger (karl@denninger.net)
    http://www.denninger.net

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