*Off Topic*I am curious about the USB comment you made, what would they replace it with? SATA? I haven't really been keeping up on the new tech. Im pretty sure my spare computer I run right now(My gaming Comp. died) runs USB 1.0. lol.

I don't know for sure.  It might be PCIe external.  But that is an expensive proposition right now.  It will get cheaper.  And buy the time USB 3.0 is done, there will probably be a new kid on the block anyway.  But don't count Ethernet out.  They have about got the price of an Ethernet interface down close to that of a USB interface.

USB will hang around simply because of the shear number of USB devices out there.  However, I do have some USB devices that don't work with Win 7.

For the end user, USB is very appealing.  Plug and play.

But there are problems with USB that people (motion developers) want to get away from.  Namely latency.  Especially with the Windows OS because USB support was grafted on.  Remember that M$ didn't WANT to support it because it hit the Apple first!  So it is kind of stuck on like a sore thumb in Windows.  The Windows scheduler is what is responsible for initiating the outgoing stream.  By default, a packet is sent every 16ms, if there is data to send and it is less than 64 bytes.  You can trim this down to 2ms with some USB devices.  And you can also do tricks like forcing the packet to 64 bytes.  In short, sending short packets at a high frequency is challenging.  So what developers HAVE to do is some sort of buffering to ensure that data gets to the device in a smooth enough stream with a quantity of data that is large enough to hide the latency. 

Another problem with USB is that it does require a device driver.  (same is true for PCIe and friends) If the maker of the USB chip set stops supporting it and decides not to write a device driver for the OS of the day, then it will run into obsolescence leaving the poor hardware developer hanging.  Ouch.  So something that doesn't require a device driver really looks nice to a hardware developer.  (Ethernet anyone?    )

I believe that low cost Ethernet based motion devices are on the horizon.  (That's a hint!)

Steve

>I believe that low cost Ethernet based motion devices are on the horizon.
Does this mean you can plug the control board to a Ethernet router or switch instead of to a PC? How about the delay by high traffic on Ethernet?

Yes.  That is exactly how I control a Galil Ethernet controller with Mach.  Typically, you want to have your controller on it's own network.  The simplest most direct way is to connect the Ethernet card in the PC and Ethernet motion device with a crossover cable.  No router or switch required.

But...  If your network is in good shape, meaning that it's functioning properly and not over utilized, then communication from the PC through a switch to the motion device is perfectly acceptable.  I have a 10Mb old school network that I use and it rocks.  The latency is in nanoseconds as compared to milliseconds with USB.

Steve

>The latency is in nanoseconds as compared to milliseconds with USB.
It is good to know Ethernet has a great advantage than the USB.
Do you have a link to your Ethernet device?

The advantage the Ethernet has over USB is purely for the developer.  Once you beat it into submission, the devices perform quite well.  There is nothing wrong with USB.

I use Galil controllers.  http://www.galilmc.com/  The Vital Systems DSPmc also uses Ethernet.  Mesa http://www.mesanet.com/ is prototyping an Ethernet device as we speak and they already have a USB and PCI/PCIe devices.  Smooth Stepper is what I would be using if I was driving steppers.  It flies!  I saw a machine running it and I was super impressed.  Then there is K-Flop too (That one looks nice.  I wish I could see it in action as well.).

My point is that external motion devices are the future.  USB and Ethernet.  There will be plenty to choose from that are within the grasp of the hobbyist.  And once someone converts from the parallel port to one of these devices, they will wonder why they didn't do it sooner.  The speed and smoothness are "unparalleled".  (pun intended.  I could not resist!  )

Steve

I would agree, I recently ran a Ethernet based 6axis motion controller and was very pleased with it.

I am running a smoothstepper under Win7 home premium 64 bit.  Works good.  Working out a electrical noise issue that knocks out comms periodically, but I have ID's the specific source and working the issue to get it running 100% (yes, it's a new installation).  It runs my machine *much* better than the PP driver ever did.

My CNC PC (XP, Dell circa '99 w/native parallel port) just died -- long story but involves pilot error re-purposing it to fix a Land Rover(!). So I just built a PC from component parts. For ~$400 I now have a lightning fast PC (specs below). This PC runs Win7 64-bit (Intel dual-core i3, 4GB). Since it was piecemealed I had to buy a parallel card (actually serial/parallel combo card). This homemade PC rivals my $2,500 dual-proc quad-core Mac Pro [8 cores w/10GB of RAM] in single task activity. (Of course my Mac Pro crushes the new PC -- I run Mac OS, Win7, Win2k, AND Ubuntu simultaneously at full speed on my Mac Pro. Yes, I'm spoiled.)

The tragedy is that I first installed Win7 32-bit, realized what I had done, and reinstalled 64-bit clean -- obviously, since it's a 64-bit architecture. Then I spent an hour getting all the right apps installed, drivers configured right, tweaking & customizing it, and THEN I realized that Mach3 only had 32-bit parallel port support. So while you guys have been going on for a while about Mach3/Parallel/64-bit/USB/etc, I just realized this TODAY. Ugh.

Ok, so now what?! I have these choices:
1) Reinstall clean with 32-bit, lose the 64-bit benefits, but gain Mach3 native parallel port support
2) Stick with 64-bit, buy something like SmoothStepper, but deal with yet another component (and cost)
3) Stick with 64-bit, try a VM (XP mode or VMware), and hope that the Mach3 driver works -- while everyone has hated on this, I've never seen a confirmation or denial
4) Stick with 64-bit, take my dormant Arduino, and take this to the next level, albeit months later

#1 *seems* wrong long-term. #2 *seems* unnecessary. #3 will definitely involve a lot of work and maybe little results. #4 means lots of time. Where are all the #4 folks?! Shouldn't CNC be USB (3.0!) now?! The signals running over these wires are not uninterpretable. I don't doubt that the Mach3 parallel driver works magic; but that's because it's parallel -- it shouldn't have to for it's purpose. Even if you had a Calabi–Yau number of axes on your CNC, it wouldn't be soaking up bandwidth or confusing components. Hopefully someone will point me to the Arduino solution to this problem so I can go with #4. But right now I'll probably try #3, get frustrated, and end up on #2 or #1.

What are the benefits of a 64bit OS?  Really?  Why do you need to address more than 4 gig of memory on a computer that runs a CNC controller?  Sure, the hardware is 64bit, but just because it's 64bit doesn't mean you have/need to use it.

Here is an analogy:  I have a 800 HP engine in a 67 Camaro.  But do I use that 800 HP to go to the grocery store?  No.  I use my 185 HP grocery getter. 

If you want to use the PP, do option #1.  You have your Mac to play on.

But I would do option #2.  Just add $159 to your $400 PC and you will be very happy.  Make that leap and I promise you that you will never want a PP again.

Option #3 (the VM stuff) is not going to work.  I run VMs for a lot of things in my day job.  And I can promise you that this option is heading down the wrong road.  The host OS has dominion over the guest OSes.  So even if the PP driver did work, it would not work correctly as it would not be the hos OS that it is running on!  Expect really crappy timings if it even works.

I would be doing Option #4 along with Option #2.  Just for the fun of it!  (Been thinking of getting one of those Arduinos for myself)

Seriously guys, 64bit Windows PCs are really only needed for insane things. 

If you run multiple VMs for development purposes, you might need a 64bit OS.
If you calculate PI to the x trillionth precision, you might need a 64bit OS.
If you run a 3D modeler with thousands of parts on an assembly, you might need a 64bit OS.
If you have a word document that is larger than 4 Gig, you might need a 64bit OS.  (only possible with Office 2010 as that is the first version of Office that is native 64bit!!!!)

My question to all is this:  Did you find yourself needing a 64bit OS last year?  Or the year before that?  Or the day before you 32bit PC died?  Where you said to yourself "Damn, if only I had a 64bit OS I could conquer the world!"

Steve

64 bit os can use memory more than 4G, which is a huge plus than the 32 bit os.