[Adamj12b]

I am looking for a PCI parallel port card card that is known to work with mach 3. I have tried 3 different cards and none of them worked. If somebody could tell me where I could buy one I would really appreciate it. -Adam

P.S. I am looking for one that is as low profile as possible.

[ger21]

www.rogersmachine.net and www.candcnc.com both sell cards that they use with Mach3, but just about any card should work. What didn't work with the three you tried? Are you sure you entered the correct port address?

[Mr.Chips]

I baught my PCI parallel card from CompUSA for I think $15. And it worked fine the first time.

Good Luck:rainfro:

[Adamj12b]

Do you know what brand card it was?

[Scott Kelley]

I am looking for a PCI parallel port card card that is known to work with mach 3. I have tried 3 different cards and none of them worked. If somebody could tell me where I could buy one I would really appreciate it. -Adam

P.S. I am looking for one that is as low profile as possible.

Did you figure out what the problem was? I am having similar problems.

[rcpilot82]

where can I figure out what the address of my port is? I am running windows xp and mach 3

[rcpilot82]

ok, I figured it out last night, i get 5v out of my port now but when the relay for the spindle / coolant turn on those pins drop to 1.4 volts. what's up with that? the relays do activate and hold but why such a drop??

[audioandy1762]

It might be to do with the current being drawn by the relays, you might be better off using your PC's 5volt to power a transistor and let the transistor pull the relay in using a seperate 5volt supply or better still use an opto isolator instead of a relay as they have a lower power consumption.

Andy

[rcpilot82]

can you provide a schematic and part numbers? I thought that was the problem but wasn't sure.

[audioandy1762]

I'm at work at the moment, but will look into when I get home, someone else might pop in in the mean time and give you a better solution but I will look it up when I get home and post a reply.

Andy

[rcpilot82]

thanks!!

[audioandy1762]

In the mean time have a look here it might help.

http://www.epanorama.net/circuits/parallel_output.html

[neilw20]

Thanks audioandy1762.
That link explains and assists in the intricacies of I/O under later OSs.

[rcpilot82]

audioandy1762
great link! helps to understand why i am getting the drop in volts. now I guess I need to build an isolator (3 actually, spindle, air selenoid, vaccum clamp)

[audioandy1762]

Hi glad you both found the link helpful.

rcpilot I have a book "Real-World Interfacing With Your PC" by James Barbarello the following is from that.

Use a 4N25 or 4N36 these are a 6 pin opto connect a 100 ohm resistor to pin 1 then connect your output from your PC to that , pin 2 goes to your PC chassis or earth. No connection to pin 3, connect a resistor to pin 4 between 1 and 10 k this goes to the negitive side of your seperate 5v supply, pin 5 will go to your relay and pin 6 will be connected to the positive 5volt seperate supply. For true isolation keep your 5volt supply negitive and your PC ground seperate.

Hope this helps

Andy

[audioandy1762]

RC just check the the above OPTO's will handle the current of your relay, if not just have a look on your componant suppliers web site and find one that will. Do you know the resistance of your relay coil? If so you can work out the current draw of the coil.

Andy

PS hope I'm not confusing you

[neilw20]

RC just check the the above OPTO's will handle the current of your relay, if not just have a look on your componant suppliers web site and find one that will. Do you know the resistance of your relay coil? If so you can work out the current draw of the coil.

Andy

PS hope I'm not confusing you

It's won't handle any extra current because the current transfer ratio of the opto-coupler is not high enough.
You will just get isolation nad not damage the PC.
You need something like a ULN2003 7 channel darlington driver to get enough current to drive the relays, unless the relays are really tiny, and they would not be able to switch the power.

The ULN2003 can drive 0.5 amps per channel but not all at once.
The total output is limited to 0.5A because of heating.

You could use multiple drivers and they can operate a 12v relay, and have the built in protection diodes (as long as you connect pin 9 to the relay supply)

[audioandy1762]

Thanks Neilw20 for clearing that up, I posted my last post after looking at the data sheet for the two opto's.

Hope we have put RC on the right track between us and he gets his problem sorted.

Andy

[rcpilot82]

Thanks for the info, I am not too confused as I have some backgound in electronics, it's just been a while. I'll look into the parts and see what I come up with.

[audioandy1762]

RC come back and let us know how you get on.

Cheers

andy