The hardware interface between PC and motor drives - the future beyond parallel BOB?
 

Here is a very recent and revealing post by Art of Mach fame:
http://groups.yahoo.com/group/mach1m.../message/79411

From that it is clear that he doesn't see a clear successor to the parallel port for use with Mach yet. Some extracts from his post:

. . . . Parallel ports are quickly going the way of the dinosaur on
new PCs and it'd be nice to know that there is an option out there
that will support the full functionality of Mach without using
parallel ports to do so. . . . .

. . . . The G100 has one nice thing going for it in
that IP and ethernet are likely going to be around for more than a few
more years. :) . . . . . .

. . . . I've had the G100 for several years now and I must say that I'm
getting a bit frustrated with the face that after all this time, it
still only supports the most basic functionality with Mach. I'm not
opposed to writing it off as a wasted investment if there is another
motion controller out there that does support the full capabilities of
Mach. . . . . .

. . . . . . . I too get frustrated by slow issues on things like the ncpod and the g100,

though both devices are good, and my G100 runs well in all operations Ive
used it for. But it is a slow moving firmware. . . . . .

. . . . . . The final output solution, when one is found, will be a team effort of
firmware , hardware, and software support. We are heading there.

In his post he mentioned that he is currently excited by yet another device called the "smoothstepper", however I recall he was as excited about the G100 and ncPod over the years.

And it must be said that there are apparently numerous other USB driven CNC systems in other parts of the world that don't use Mach. (TechLF for example). Art & Mach are under huge pressure to keep up, but he seems locked to his parallel port approach and is thus excited by a good USB to parallel converter?

I think the difference with this one is, the developer has gone to Art and said "What do you need a USB device to do"

The others have been existing devices that Art has tried to adapt.

They have always wanted to do certain operations within their own software. EG homing and feedhold

This one, I believe, is just going to take instructions from Mach. Anyway here's hoping. :)

Greg

I think there is too much emphasis on Mach being the "ultimate" and that hardware is the problem. There is a line drawn between two camps - Mach one side and hardware developers on the other. I think for Mach to stick to 25 pin parallel ports is a problem that will hold everyone (in low-cost CNC) back. . . . . . until someone totally new enters the market. Other guys (like TechLF) are there already, but their foreign non-English status counts against them.

Is the problem really that complex? To read g-code with a PC and send pulses to drives? My feeling is that someone who is willing to step back, outside his comfort zone, and who looks at software and hardware together, focussed on CNC motion, is going to win this one. Art doesn't do hardware, Mariss doesn't do CNC, and third parties are volunteering to get them talking . . . .

(Here is another USB to parallel type system, http://www.super-tech.com/root/itm.asp?p1=itm-SuperCamXp , which also gives me the impression it is constrained by "parallel 25 pin-based" software? ie the USB/parallel adaptor is a patch to compensate for the fact that the parallel port is dying?)

By Mariss last night:

The G-Rex has been a huge disappointment for me. The development time
took 5 years and untold $$$. By comparison, the G203V drive took less
than a year and only $25,000 in direct expenses to develop. It is an
idea I probably loved too much and I loved it for too long. It is
expensive to build, expensive to test and very expensive to support.
In a word, it is nearly unprofitable.

The mistake was misapprehending what our strengths and weaknesses are.
We design good hardware, we are not so good at firmware. The G-Rex
needed both. Second, the G-Rex is being squeezed by improving PC-only
solution step pulse rates at one end and me-too, less expensive
similar products from the other end.

I cannot justify investing any more effort and expense into further
development, hardware or firmware, of the G-Rex given its past market
performance and future potential. Instead, that effort and expense is
going into new motor drives. The Rabbit fiasco was the last nail
driven into an already expensive coffin.

We will always have the G-Rex available. We ordered 500 more G100
boards yesterday. We just aren't going to develop it any further.

MM Forum.
I for one, am disappointed at this news. Great product potential that will not be developed further. On the upside...the NCPOD looks like a great USB supported option as the PC market moves away from Parallel ports.
Thanks for passing on the forum note Gerald.

There is also the smoothstepper, It sounds very promising and is in testing right now
http://www.machsupport.com/forum/ind...ic,4583.0.html
http://www.machsupport.com/forum/ind...ic,4597.0.html
And the manufactures website
http://www.warp9td.com/index.html

Are folks running parallel cards on the new PCs for their machines? Do they make them and are there different types for different computer models?

I realize that I cannot use my Macs to run the MechMate, but I am somewhat a novice when it comes to the PC side...

I would like to be able to purchase a new or newer machine rather than hunt down an older one just for the parallel output...
Thanks much...
Bill Mcguire

Most PC's have vacant "PCI expansion slots". You buy a "parallel port expansion card for PCI slot" and plug it into the PC's vacant slot. They are interchangeable between brands. Some PC's have a parallel port direct on the motherboard, but it is recommended that you still use an expansion card.....cheaper to damage! :)

Re: parallel cards
 

Thanks Gerald...
I will be able to sleep easier now... :D

interface
 

I doubt that Mach will be rewritened to another interface other than printer port. That would be a MAJOR !! project. However it is relatively easier to build the hardware to emulate the printer ports. Presently USB is the leading conteder but I belive that wireless is the future and what that interface will be is anyone's guess.

I have seen some ads for a parallel port that hooks up to the usb port. I have not used one yet to see how they work. Has anyone seen this or perhaps used one with a cnc unit?

The USB to Parallel converter did NOT work for me. (I use a similar USB to Serial converter on my Shopbot PRT-Alpha, which does work; however, the Shopbot's software was designed to use a USB to Serial converter.) Perhaps I had a setting set wrong for the USB to Parallel unit, but I gave up after fiddling with the unit for about 30 minutes.

If the USB/parallel converter did work, we would have heard lots about them. :)

still growing
 

Keep in mind that DIY CNC is still in it's infancy. Just in the last few years have we had the hardware and software avaliable to do the job. I expect the USB will be fixed by several people within a year. Last I heard USB with Shopbot is not fixed but a work around of adding a USB hub apparently fixed the problems. Look at the controlers avaliable. None are really a clean solution but componets that are cluged togeather. NcPod was the first attempt a total controler and someone els will take on the project of a fully intergrated controler. The market potential is too great to be ignored. G and M codes come in several varietes. Control software is mainly property with the major manufactures and from what I understand only Mach the only one that has serious resources devoted to development that is not propority.
I suspect that Mach business plan is to use the DIY market to pay for the development of it's entry level software and to begin to capture the commercial market with its price and superior funcutionaly. Where they will realy make their serious money is Quatum. It appears to me that Mach has the real posibility of capturing the controler market by providing a superior product at a very cheap price. Most manufactures would be glad to get rid of the software side whick consumes a lot of resources for relatively few copies.

Art, I think you are seriously over-estimating Mach. It is a 1.5 man "company" of which person no.1 is retiring within 3 weeks. Mach was the hobby of Art Fenerty, and he only left his day job about 2 years ago. It remains to be seen if Mach will advance after Art's retirement.

I totally agree with Gerald. Process control is an incredibly complex issue. Having Mach software available that works 'most of the time' with 'existing' hardware is uncommon in the process control world. Other companies have used proprietary hardware and proprietary software in order to control the variables that would keep their solution from working. Art has taken the broader approach and tried to make the common parallel port work. In my opinion, he has done a masterful job; however, he cannot dictate to the hardware manufacturers that they must continue to furnish motherboards with built-in parallel ports. The G100 was one alternative - which is being pulled from the market. USB is another alternative. It's too soon to know if USB is the ultimate answer. Meanwhile, those who count on Mach software can easily insure success by buying a low cost PCI parallel port board. At my local CompUSA store, those boards are available for less than $30.

Mike, a lot of folk are hyped up about the beta SmoothStepper (mentioned earlier in this thread) which will plug directly between USB and the PMDX-122. In this burst of interest around the SmoothStepper, the ncPod has moved out of the limelight, but the talk is that the ncPod's bugs have mostly been cured. In other words, don't get too many parallel port PCI cards now . . . . :)