I got into Mach 3 manuals and discovered that USB to parrallel is a no-go.

I went to Best Buy and found that parrallel ports are not on today's computors-


How do I go about obtaining a parralel port?

Hi

If you have a free PCI port in your computer you can install something like this in it.

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1003991&CatId=512

Regards

Thomas

If this is for a laptop, you might try a PCMCIA slot parallel port adapter. For a desktop, just by a PCI parallel port card.

Alan

If you are using a PC with a free PCI slot this should work for you.

Rosewill Single Parallel (SPP/PS2/EPP/ECP) Universal PCI card Model RC-302

http://www.newegg.com/Product/Product.asp?Item=N82E16815166005

http://www.cables4computer.com/newproduct/Prod_Individual3.aspx?groupcode=I0689

Is there any reason to buy this over the newegg product??

Is there a difference in quality between one unit and another??

http://www.cables4computer.com/newproduct/Prod_Individual3.aspx?groupcode=I0689

Is there any reason to buy this over the newegg product??

Is there a difference in quality between one unit and another??



Just by reading the specs between the two cards the one is a little better and can transfer data faster. Now weather you need to be able to transfer data faster I dont know but the New Egg one will do 1.5mb a sec & the other will do 5mb a second data transfer. Also the better one says it is backwards capatible which may help it work with a older computor if you ever needed it to. The NE one didnt even say if it was backwards capatible. Who knows the cheap one may even be better but the other one does have better specs.


Jess

On a nother note here is some onfo on Pcards that is interesting & you should read it. I copy/pasted this from the IH site.





A computer is a horribly complex piece of equipment, lots of pieces, some big, some small, but all important. To make matters worse is the folks who make the computers all get together and make up the rules on how computers should operate.
So what does this have to do with CNC?
Nothing and everything. A few years ago every parallel port/card on the planet worked at the 5 volt level. This was “the good old days” as 5 volts is considered a TTL High and the parallel port could be easily connected to any other device and everything worked great. But somewhere between then and now, “they” got together again and started lowering the voltage for the parallel port. Currently I believe the spec is 3.3 volts (don’t quote me on this) and I’ve seen it as low as 2.4 volts.
Back to CNC
The problem is CNC devices need some decent voltages. A Gecko for example requires a 5V signal to work properly and most popular breakout boards require at least 3 volts. Without the proper voltage you get erratic operation, no operation, or just flat out flakiness.
The Solution
First of all, we had to find a 5 Volt card as for the most part we don’t use a breakout board, so our search for a good card took a little longer than it might have if we used a breakout board. But we went through about a half-dozen before we found the one we like.
The card we like is the SIIG CyberParallel PN JJ-P001122-B and you can find it on the web here and there. It is NOT the cheapest card and I have seen it retail for as much as $45. On the flip side I found it for $18 and bought out all the stock from one web supplier, so the deals are out there, you just have to look.
Just to give this little tip some credibility, I was at a customers place this past weekend and low and behold nothing worked with a bran-new 4 GHZ Gateway. After breaking out my handy dandy silly-scope and saw 2.4 volts on the port I knew the problem. Dropped in a new card and the problem was solved.
Furthermore, when someone purchases a turn-key machine from us, we put a card or two in their PC before we ship it all back. We don’t even test to see if it needs it. It’s simply “part of the deal”.
Long and Short
If nothing works, but everything is right.
It’s not acting ‘right’
It’s possessed
Or
You’re just really, really smart and want to avoid a headache to start with.
Get the card.




I dont know how to find out if the card is 5v beside measering it with a DVOM or calling them up and asking. There may be something in the info of the cards that dictates that it will put out 5v but I am not sure what it is.


Jess

I didn't find one of those cards of the same model, but I found a siig card and I guess I'll buy it to give myself some insurance.

The printer port or parallel port on PC is an old I/O interface from the age of 1980's which was originally for IBM PC AT (8086 CPU). Over years, there have been improvement on this interface known as ECP/EPP. However, I think the CNC control software still uses the parallel port in an old standard way.

The standard parallel port usually supports only about 400KHz data rates no matter how fast you really writes to that port, the CPU can simply be blocked by the I/O device. Note that it is a port for printer not for generic high speed I/O.

Theoritically, it is possible to have a transparant USB to parallel port bridge. The driver can trap the access to a parallel port I/O address and forward the request to a USB function device which provides the physical signals as the parallel port. However, with this method, the speed and the latency will be worse than an ordinary parallel port. It looks like the comercial one does not work in this way.

I hate to use a PC for the motor timing. Neither the XP nor the normal Linux was designed for the real-time timing. I'll probably develop an isolated controller with USB and Ethernet interface, if I need to convert a mill to CNC by myself. The first design might be an integrated controller with 4 stepper drivers.

Sorry for my off-topic.

GreenO,

What brand computer were you looking at? I just bought a 3.2mhz desktop from Best Buy and it was standard on my machine. Are you looking at laptops?

LAter,
Tim

Same PC.

I was told by the salesman that it didn't have a parrallel port, but when I got it home it did.

I guess I'll have to see if it works. I have a friend who's parrallel works with his CNC/E-machine combo; so maybe I'll luck out.

If not I guess I'll buy one.

Green,

I bought the 3.2Ghz E-Machines computer. E-Machines are now made by Gateway so I know they are good pieces. I have no problem running Mach 3 with a Xylotex drive off it.

LAter,
Tim

try this http://www.transdigital.net/. I ordered one after some emails with them. They swear that you will get 5v. I will let you know if it works.

I am using the transdigital and it works fine with my laptop a Dell 6000.

Woodenspke

Parallel ports are only going to become scarce. At some point CNC users will need to adopt USB or demand USB compatibility from manufactures.

A comparison:
http://www.totalphase.com/support/articles/article05/

[The TTY boxes that hearing-impaired people use are very costly--because few companies make a modem chip that will go slow enough.]

Isn't this what e-bay is for? Pick up an 'old' desktop for about $30 with a parallel port. :)

USB does not have the latency needed for machine control.
Ethernet, OTOH, can have low latency if used on a dedicated network


Parallel ports are only going to become scarce. At some point CNC users will need to adopt USB or demand USB compatibility from manufactures.

A comparison:
http://www.totalphase.com/support/articles/article05/

[The TTY boxes that hearing-impaired people use are very costly--because few companies make a modem chip that will go slow enough.]

Going slow is easy, most serial chips can divide down to hit very slow baud rates. The problem is selling enough to drop the production costs; that's why the government mandated closed caption decoders in televisions, simply to drop the costs.

Aaron

It's not just a question of the USB topology, it's also a question of software support.

For instance, in MS Windows, the USB sampling rate is detuned for compatibility. There are third-party utilities to sample the ports faster, such as this example can tell windows to poll the ports more than 8 times faster, down to 1 millisecond, if your particular chip will take it.

http://www.softpedia.com/get/Tweak/System-Tweak/USB-Mouserate-switcher.shtml

I am sorry i didn't make myself clear; I meant TTY boxes such as these:
http://www.abouttty.com/Whatis.html

They seem to cost $250-$350, and they go 50 baud!