CNC Machines & RS232 Serial Ports

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m4martin · #1 Post by **m4martin** » Wed Dec 05, 2007 8:56 pm

Does anyboy have experience of using a T40P or T42P with a CNC machine.

Specifically, i need to drip feed programs from the PC into the CNC using drip feed software (DNC).

I have tried a USB to Serial with no success. I am told it is because the usb creates a kind of psuedo port, not a real hardware one.

Has anyone had results with a PCMCIA RS232 Adaptor, or will the advanced dock do the job???

Thanks

Martin

Phazer · #2 Post by **Phazer** » Wed Dec 05, 2007 9:36 pm

What kind of machine? Does the machine have a PCMCIA port?

We had a couple of old Pumas that had a PCMCIA and it was fairly hard to do back ups and restores. We found it was easier to put one program on the PCMCIA and load it without a program number and when it was loaded, it would create a new number. The HAAS' we had sometimes had trouble with programs that were edited with Word or Notepad, (can't remember which) and a CF or CR sometimes caused problems. Sorry...not clear on the drip method you mention.

Mikem95626 · #3 Post by **Mikem95626** » Wed Dec 05, 2007 9:46 pm

I have personally had much better luck communicating with a pcmcia serial adapter as opposed to any usb to serial adapters.
I have a T42 and have to communicate with various relays and devices in power substations, and the usb ones are always hit and miss.
Hope this helps,
-Mike

sojourner · #4 Post by **sojourner** » Wed Dec 05, 2007 10:09 pm

Hey Phazer! Fancy meeting another machinist on this forum. Never thought I'd see a post like yours

I have never tried the proposal you suggested (PCMCIA) but theoretically it should work because the PCMCIA bus on TP's have a 32 bit bus (actually these PC's are CARDBUS), so far as I know (if I'm wrong, someone please correct). That being the case, it would be similar to adding an RS-232 port via an addon card in a PCI slot on a typical PC ... which would allow the communications you are seeking!

You really got me going on this communications question because I use REAL RS-232 ports on an old PC for communicating with a VMC and also for HAM radio communication software/hardware, and have wondered how to get serial communications on the laptop. In HAM circles there has been a LOT of talk on USB to serial port converters and frankly, I've not seen anything definitive for a 'good' adapter.

Lets hope someone has real life experience with this issue!

BTW: checking ebay I saw this card which boasts a UART compatible to the 16C550 (high speed, buffered) we're familiar with, so I wonder ???

http://cgi.ebay.com/RS232-Serial-DB9-Ca ... 0178821668

one more:
http://cgi.ebay.com/Hi-speed-PCMCIA-RS2 ... 0186641708

lastly:
http://www.amazon.com/gp/product/B0001E ... roduct_top

This one from Amazon has VERY good reviews, but will it do DNC operation?

#5 Post by **rkawakami** » Wed Dec 05, 2007 11:14 pm

On the subject of CNC machines, this recently popped up in the T2x/T30 conference:

http://forum.thinkpads.com/viewtopic.php?t=53178

#6 Post by **bill bolton** » Thu Dec 06, 2007 12:10 am

Check out....

http://www.shopfloorautomations.com/ser ... veview.php

http://www.pfranc.com/usb/usb.shtml

Cheers,

Bill B.

Likvid · #7 Post by **Likvid** » Thu Dec 06, 2007 8:13 am

I never understood why they removed the RS232 interface on the thinkpads.

I work alot with routers and switches as a network engineer and it's always ackward to have a USB dingle with you on the field.

m4martin · #8 Post by **m4martin** » Thu Dec 06, 2007 7:12 pm

Hi All,

I had a feeling my question would spark some interest.

The machines i am trying to communicate with are a Bridgeport Interact 4 mill with a Heidenhain TNC151B Control, and a Hyundai Hit-8s Lathe with a Siemens 840C Control.

I have just agreed to buy EdgeCAM CAM software, which i think will provide the dripfeed to the mill as i think it has a DNC utility.

When the EdgeCAM software engineer visited he said they all have great trouble with RS232 interfaces, so they tend to use old Dell or similar laptops that still have a serial port. i.e they have not found the answer yet. In fact they suggested i bought and old PC just for the job of dripfeed.

For those that don't know:
When a Computer Numerically Controlled (C.N.C) machine tool is being dripfed positional numeric code, the code is often fed to a buffer in the CNC, if the buffer runs empty, it can stop the machine, and you have to start over. That is a bad thing if the program takes 10 hours to run! So the last thing that is needed is a PC to be of on a distraction, screen saver or something, when the RS232 port should be feeding data.

As i understand, USB serial converters, are notoriously difficult because they are software based.

I did find some ethernet to serial adaptor that could work in both directions, but you needed to be a software engineer to set one up, far to complicated for my little brain.

So i just want a simple, stable, good ol' fashioned serial port. on my trusty T42P. I wonder if the advanced dock works, or PCMCIA, or even a PCI card in the advanced dock?

Can we beat it guys, i have faith in you!

Martin

m4martin · #9 Post by **m4martin** » Thu Dec 06, 2007 7:14 pm

Just off now to investigate all your replies, thanks

m4martin · #10 Post by **m4martin** » Thu Dec 06, 2007 7:45 pm

Reply to Bill the PFranc usb adaptors look very impressive, one of the comments said they tried about 14 others and only one other a Pfracs purple adaptors worked.

I also noticed a comment on the PCMCIA adaptor which said they could not configure a com port number as it was fixed, and some software requires only com 1 or 2. Which was interesting, although i would have thought it should be and excellent method as it links straight into the Thinkpads motherboard databus.

i may try both here in UK if i can get them ok.

CNC Machines & RS232 Serial Ports

CNC Machines & RS232 Serial Ports

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