Loading ...
Sorry, an error occurred while loading the content.

Re: [ccd-newastro] Wireless USB interconnects

Expand Messages
  • Yahoo - Wodaski
    What gets interesting are the interactions with other software. The protocol, under ideal conditions, can I am sure handle things. But what happens when the
    Message 1 of 12 , Dec 4, 2006
    • 0 Attachment
      What gets interesting are the interactions with other software. The
      protocol, under ideal conditions, can I am sure handle things. But what
      happens when the camera driver, telescope software, other drivers,
      network, etc. are all haranguing the CPU for time? <G>

      This is just one of those things that we'll have to see in use to really
      learn what it can, and cannot, do.

      Ron

      Stu Goossen wrote:
      > Actually I over spoke a bit. UWB is the radio protocol. WUSB <wireless usb>
      > is the high level protocol.
      >
      > <which is still designed to deal with the retry issue, and to handle the
      > needs of 'real time' transmission>
      >
      >
      >
      > Cheers,
      >
      > sjg
      >
      >
      >
      > _____
      >
      > From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
      > Behalf Of Mark de Regt
      > Sent: Monday, December 04, 2006 6:05 PM
      > To: ccd-newastro@yahoogroups.com
      > Subject: RE: [ccd-newastro] Wireless USB interconnects
      >
      >
      >
      > Stu,
      >
      > Thanks for the clarification. I also don't have a high opinion of Belkin
      > stuff, buying it only when I have to buy the tool, and nobody else makes it.
      > Sometimes it even works....
      >
      > --Mark
      >
      >
      >> -----Original Message-----
      >> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>
      > yahoogroups.com
      >
      >> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>
      > yahoogroups.com]On Behalf Of Stu Goossen
      >
      >> Sent: Monday, December 04, 2006 4:31 PM
      >> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com
      >> Subject: RE: [ccd-newastro] Wireless USB interconnects
      >>
      >>
      >> Just a nit, but the 'protocal' running over the wireless connection is UWB
      >> <ultra wide band> not USB. And UWB is designed to deal with packet
      >> loss/retransmition.
      >>
      >> Of course if this was from someone besides Belkin, I'd really be
      >> excited :-)
      >>
      >>
      >>
      >> Cheers,
      >>
      >> sjg
      >>
      >>
      >>
      >> _____
      >>
      >> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>
      > yahoogroups.com
      >
      >> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>
      > yahoogroups.com] On
      >
      >> Behalf Of Mark de Regt
      >> Sent: Monday, December 04, 2006 12:54 PM
      >> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com
      >> Subject: RE: [ccd-newastro] Wireless USB interconnects
      >>
      >>
      >>
      >> Adam,
      >>
      >> Thanks for this. But I'll not be an early adapter, since it will take some
      >> powerful evidence to show me that the wireless isn't causing more problems
      >> than it's solving in this application. USB is a great protocol,
      >> but I'm far
      >> from convinced that it will function as well in wireless form as wireless;
      >> dropped packets is a bad thing!
      >>
      >> --Mark
      >>
      >>
      >>> -----Original Message-----
      >>> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>>
      >> yahoogroups.com
      >>
      >>> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>>
      >> yahoogroups.com]On Behalf Of adam_block
      >>
      >>> Sent: Monday, December 04, 2006 11:40 AM
      >>> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
      >>>
      >> yahoogroups.com
      >>
      >>> Subject: [ccd-newastro] Wireless USB interconnects
      >>>
      >>>
      >>> Wireless USB has been discussed a few times in the past on this forum
      >>> and the market has been expecting it for a while. Now the first
      >>> wireless USB device is coming to market:
      >>>
      >>> http://www.engadget
      >>>
      >> <http://www.engadget
      >>
      > <http://www.engadget.com/2006/12/04/belkins-cable-free-usb-hub-fina>
      > .com/2006/12/04/belkins-cable-free-usb-hub-fina>
      >
      >> .com/2006/12/04/belkins-cable-free-usb-hub-fina
      >>
      >>> lly-loosed/
      >>>
      >>> It will be interesting to see if astrocams can run reliably over this
      >>> protocol. I recall previous posts which explained that delays in
      >>> reading data over wired USB could increase noise.
      >>>
      >>> /afb -- "Not *that* Adam Block"
      >>>
      >>>
      >>
      >>
      >>
      >> [Non-text portions of this message have been removed]
      >>
      >>
      >>
      >> Yahoo! Groups Links
      >>
      >>
      >>
      >>
      >
      >
      >
      >
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
    • Yahoo - Wodaski
      It s complicated, as alluded to in my other reply - interaction and demands on the CPU s time are what is critical. Interestingly, a CCD camera that utilized
      Message 2 of 12 , Dec 4, 2006
      • 0 Attachment
        It's complicated, as alluded to in my other reply - interaction and
        demands on the CPU's time are what is critical.

        Interestingly, a CCD camera that utilized the full rate of USB 2.0 would
        actually be much noisier (typically) than one that was slower! The read
        noise is minimized at a certain transfer speed, and most cameras that
        seek to be low noise operate at or near this optimum transfer rate. In
        most cases, it is well below the transfer rate of USB 1.1.

        I also wish more manufacturers would put memory in the camera to dump
        the CCD data into. I work with a number of clients who have pro-level
        cameras, and not only do such cameras always have internal memory, they
        often use creative schemes to make best use of the memory - e.g.,
        storing dark and bias frames in that memory for instant application to
        the incoming frames.

        But you get what you pay for; such cameras are in the $25-100k range.
        :( Some brands do include memory in the camera, but a camera purchase
        decision is a complicated thing. Some vendors don't test thoroughly;
        others provide poor service. You really have to decide what is most
        important for you. If you just want to use the camera without too many
        problems, then SBIG fills the bill, despite the memory issue. And if you
        are willing to keep your camera-control computer reasonably free of
        potentially interfering software (e.g., put the software for your phone
        interface somewhere else), you can do better.

        Ron Wodaski

        adam_block wrote:
        >> The root problem with packet loss/retransmission is that it generates
        >> excessive read noise. Anything that causes a delay in reading the
        >> readout register will increase noise. Retransmission could do that
        >>
        > quite
        >
        >> easily.
        >>
        >
        > Is this universally true (up to the maximum rate at which the CCD can
        > dump data, that is)? In other words, will a USB 2.0 camera by
        > definition have less read noise that one with USB 1.1, which will
        > itself be less noisy than a parallel camera?
        >
        > I don't understand why this limitation couldn't (and wouldn't) be
        > address by manufacturers by putting buffer memory between the CCD and
        > the comm. interface to ensure data is dumped from the chip at an
        > optimum rate, a rate insensitive to the performance of the camera's
        > communications protocol.
        >
        > /afb
        >
        >
        >
        > Yahoo! Groups Links
        >
        >
        >
        >
      • Bob Denny
        ... Only if the imager is unbuffered. That excludes most modern designs, but does include (at least) one relatively popular imager maker. They have known about
        Message 3 of 12 , Dec 4, 2006
        • 0 Attachment
          The other Adam Block:
          >I recall previous posts which explained that delays in
          > reading data over wired USB could increase noise.

          Only if the imager is unbuffered. That excludes most modern designs,
          but does include (at least) one relatively popular imager maker. They
          have known about the problem for years, and have announced that they
          intend to make changes in new designs. Only time will tell... results
          are king.

          Meanwhile, I think you're right in bring the issue up. Best practice
          would be to ask the imager maker. Make sure you ask about on board
          frame buffering first... and if the answer is "not yet", treat all
          subsequent claims with skepticism! I have seen unbuffered imagers
          violate Windows interrupt rules by a factor of 10,000+++!
        • Stu Goossen
          kind of applies to all interconnect protocol s. (and/or the lack of properly buffered hardware) the difference between USB and wireless USB protocol CPU
          Message 4 of 12 , Dec 4, 2006
          • 0 Attachment
            kind of applies to all interconnect protocol's. (and/or the lack of properly
            buffered hardware) the difference between USB and wireless USB protocol CPU
            consumption is insignificant.

            And of course protocols are never designed to operate in only 'ideal'
            conditions, actually it's usually just the opposite. they are over designed
            for the corner cases.



            Cheers,

            sjg



            _____

            From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
            Behalf Of Yahoo - Wodaski
            Sent: Monday, December 04, 2006 7:14 PM
            To: ccd-newastro@yahoogroups.com
            Subject: Re: [ccd-newastro] Wireless USB interconnects



            What gets interesting are the interactions with other software. The
            protocol, under ideal conditions, can I am sure handle things. But what
            happens when the camera driver, telescope software, other drivers,
            network, etc. are all haranguing the CPU for time? <G>

            This is just one of those things that we'll have to see in use to really
            learn what it can, and cannot, do.

            Ron

            Stu Goossen wrote:
            > Actually I over spoke a bit. UWB is the radio protocol. WUSB <wireless
            usb>
            > is the high level protocol.
            >
            > <which is still designed to deal with the retry issue, and to handle the
            > needs of 'real time' transmission>
            >
            >
            >
            > Cheers,
            >
            > sjg
            >
            >
            >
            > _____
            >
            > From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            yahoogroups.com [mailto:ccd-newastro@
            <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com] On
            > Behalf Of Mark de Regt
            > Sent: Monday, December 04, 2006 6:05 PM
            > To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com
            > Subject: RE: [ccd-newastro] Wireless USB interconnects
            >
            >
            >
            > Stu,
            >
            > Thanks for the clarification. I also don't have a high opinion of Belkin
            > stuff, buying it only when I have to buy the tool, and nobody else makes
            it.
            > Sometimes it even works....
            >
            > --Mark
            >
            >
            >> -----Original Message-----
            >> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>
            > yahoogroups.com
            >
            >> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>
            > yahoogroups.com]On Behalf Of Stu Goossen
            >
            >> Sent: Monday, December 04, 2006 4:31 PM
            >> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com
            >> Subject: RE: [ccd-newastro] Wireless USB interconnects
            >>
            >>
            >> Just a nit, but the 'protocal' running over the wireless connection is
            UWB
            >> <ultra wide band> not USB. And UWB is designed to deal with packet
            >> loss/retransmition.
            >>
            >> Of course if this was from someone besides Belkin, I'd really be
            >> excited :-)
            >>
            >>
            >>
            >> Cheers,
            >>
            >> sjg
            >>
            >>
            >>
            >> _____
            >>
            >> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>
            > yahoogroups.com
            >
            >> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>
            > yahoogroups.com] On
            >
            >> Behalf Of Mark de Regt
            >> Sent: Monday, December 04, 2006 12:54 PM
            >> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com> yahoogroups.com
            >> Subject: RE: [ccd-newastro] Wireless USB interconnects
            >>
            >>
            >>
            >> Adam,
            >>
            >> Thanks for this. But I'll not be an early adapter, since it will take
            some
            >> powerful evidence to show me that the wireless isn't causing more
            problems
            >> than it's solving in this application. USB is a great protocol,
            >> but I'm far
            >> from convinced that it will function as well in wireless form as
            wireless;
            >> dropped packets is a bad thing!
            >>
            >> --Mark
            >>
            >>
            >>> -----Original Message-----
            >>> From: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>>
            >> yahoogroups.com
            >>
            >>> [mailto:ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>>
            >> yahoogroups.com]On Behalf Of adam_block
            >>
            >>> Sent: Monday, December 04, 2006 11:40 AM
            >>> To: ccd-newastro@ <mailto:ccd-newastro%40yahoogroups.com>
            >>>
            >> yahoogroups.com
            >>
            >>> Subject: [ccd-newastro] Wireless USB interconnects
            >>>
            >>>
            >>> Wireless USB has been discussed a few times in the past on this forum
            >>> and the market has been expecting it for a while. Now the first
            >>> wireless USB device is coming to market:
            >>>
            >>> http://www.engadget
            >>>
            >> <http://www.engadget
            >>
            > <http://www.engadget
            <http://www.engadget.com/2006/12/04/belkins-cable-free-usb-hub-fina>
            .com/2006/12/04/belkins-cable-free-usb-hub-fina>
            > .com/2006/12/04/belkins-cable-free-usb-hub-fina>
            >
            >> .com/2006/12/04/belkins-cable-free-usb-hub-fina
            >>
            >>> lly-loosed/
            >>>
            >>> It will be interesting to see if astrocams can run reliably over this
            >>> protocol. I recall previous posts which explained that delays in
            >>> reading data over wired USB could increase noise.
            >>>
            >>> /afb -- "Not *that* Adam Block"
            >>>
            >>>
            >>
            >>
            >>
            >> [Non-text portions of this message have been removed]
            >>
            >>
            >>
            >> Yahoo! Groups Links
            >>
            >>
            >>
            >>
            >
            >
            >
            >
            >
            > [Non-text portions of this message have been removed]
            >
            >
            >
            > Yahoo! Groups Links
            >
            >
            >
            >





            [Non-text portions of this message have been removed]
          Your message has been successfully submitted and would be delivered to recipients shortly.