Parallel port adapter help.

[Rocco85]

Hi, I'm new around here, I've just started investigating the possibility of building a CNC router or mill. One of the first things that I've discovered is that it looks like I'm going to need a computer with a parallel port. My current computer is a laptop with USB ports only. I've come across the adapter card described below, will this work? And if not, what do I need?

PCMCIA CardBus DB25 Parallel / Printer 1-Port Adapter, RoHS Compliant
• Compliant with 32-Bit PCMCIA CardBus PC Card Type II standard
• Single DB25 Parallel connector
• IEEE 1284 compatible parallel port, supporting SPP, PS2, EPP and ECP modes
• Transfer rate: up to 1.5 Mbps
• 16-byte First-In-First-Out (FIFO) buffer
• Support Hot-Plug feature
• Work with Microsoft Windows 98/ME/2000/XP/Server 2003/Vista 32bit&64bit, Linux or DOS

[Dorsal]

Probably not.
A CNC controller card needs signals on 16 of the pins, as I recall - and the VAST majority of those adapters only support data output on enough pins to run a printer (6 pins of data). I investigated it myself a while back, and decided to buy a SmoothStepper card to run my 3-axis CNC from my Dell laptop. Although the laptop actually has a parallel port, there is a file in the root directory of Mach called drivertest.exe that showed the signal quality from that port could never run the CNC controller card. The SmoothStepper runs from a USB port but outputs to a DB25 port which you then connect to the controller card. The SmoothStepper is designed for running CNC machines, and it costs only $20 more than a good, usable PCMCIA-Parallel card was going to cost.
Go here: http://www.warp9td.com/index.php to read up on it and don't be intimidated by their "waiting list", the product is well worth the wait.

[Rocco85]

Thanks for your input. Anyone else confirm, refute or just comment?

[Zygoat]

im not going to say he is wrong, because i dont know for sure. but most of the manufactures recommend a second port if you need more inputs and outputs for your machine. i have to think that quite a few of the guys one here are running there machines on them. but like i said i have not confirmed this. maybe a source for your info?

i have been building computers for over a decade. never heard of it. but i wasn't running cnc's either.

[mkc2]

Hi all

I have used one of those cards to control my cnc router without having any problems, but they do recommend using a desktop pc over laptops.
Just my input.

Cheers Michael

[markcomp77]

Originally Posted by Rocco85 Anyone else confirm, refute or just comment?

lpt via pcmci is possible (I checked this), but...
but especially laptop is not stable source of frequency

[Torchhead]

Virtually all PCI port expansion cards support bidirectional I/O (EPP or ECP) and work fine with MACH or EMC to generate pulses and do high speed I/O. We have used hundreds of cards (average cost about 20 bucks) that install and work perfectly. We typically shop for cards using the MOSCHIP chip set since their drivers seem to work with no problems on XP. The brand names change a lot but the boards all look the same that have the same chip set and use the same drivers. Spending more money on a port card will not insure it will work better or do anything the cheap one will do. The 14.00 ones on www.newegg.com work just as good as the 30.00 (

Another option is to consider a refurbed Pentium 4 box. For about the same cost as a Smooth Stepper you can own a 3Ghz Dell with 1G ram , internal Parallel and serial ports, and XP Pro loaded. There are several stores on EBAY that will ship you a desktop (mini-tower) for around 139.00 to 169.00 bucks. They make perfect CNC control PC's. The PC running your table should be considered "dedicated" to that task. Your design and CAM functions are better done on a separate computer and the cut files transferred to the Controller PC via Ethernet or Memory Stick. After losing 2 laptops to misfortune and shop dust we no longer use them for anything in the shop. Laptops are for working portable and are great for travel and field work.

PM me for links to sources for cards, and the refurbed PC stores.

TOM caudle
www.CandCNC.com

[markcomp77]

JITTER -->> measure of usefulness of pc-computer in cnc traffic control
http://wiki.linuxcnc.org/emcinfo.pl?Latency-Test

[Rocco85]

Okay, thanks guys, I think I'm going to take a $20 gamble and try one out.

Follow up question: once I've gotten the adapter, is there some Windows software available that I can use to assess it's suitability?

[Torchhead]

After the install open Windows Device Manager and make sure the port shows up as an LPT (number does not matter). Then open the resources tab for that port and write down the hex BEGINNING address for the card. Then configure the PORT in MACH to "look' at that address. If it's done right you should see the first 7 or 8 LEDs across the top of the RAW PORT BITS monitor in Diagnsotics tab ON (green). If they are all greyed out then MACH is not talking to the PORT address correctly.

You will need to have MACH setup to read the proper inputs so you can test. The assigned inputs on a simple BOB are pins 10, 11, 12, 13 and 15. Normally pin 10 is reserved for E-STOP so you have 4 inputs you can use.

Outputs are mapped in the Ports & Pins and Motor Outputs (for step & dir signals) and are typically pins 2-9. The other outputs pins 1, 14, 16 & 17 and are open for use with either functions. Often 17 is used for Charge Pump.

TOM caudle
www.CandCNC.com

[Rocco85]

I'd rather not do an install on MACH just yet, are there any small stand alone programs that'll let me test the port?

[mlabruyere]

There are also specific modifications you need to make tot he OS on the laptop. The reason is the power management functions used on the laptop may casue issues for you. Here are some of the details:

http://www.machsupport.com/forum/ind...ic,3378.0.html