CNC Card Reader

Steve@Advance

Well-known Member
We have a Kia SKT-25 CNC lathe with a Fanuc series 0i-TB controls in our shop. It is the only machine we have that doesn't have a CompactFlash card reader built into the control. All it has is the RS232 port to load programs.

Does anyone know if a simple adaptor from the CompactFlash card to the RS232 port allow us to use the CompactFlash card with this machine or is there more to it?

Thanks!
 
Steve,
RS232 is a serial interface that has been almost completely obsoleted by USB.
As a Serial interface, it transmits 1 bit at a time, at very slow rates (like 9600 BPS). See this Wiki article.
http://en.wikipedia.org/wiki/RS-232
A db25 or db9 connector is used. A modem was a common device used on a serial port.
I have in the past used a serial port to communicate with a CNC machine. Most of that was done on the VMS operating system.
Basically you would create the tool path file on the VMS machine and then send it to the CNC machine. We used a CAD/CAM software program to create the tool path in a text file and then type the file out the serial port after we set the NC machine to read in from it's serial port.
Worked fine after you got all the details worked out. Those being port speeds, DTE or DCE or none etc. Then you got a cable made to those specs.
Port setup on a PC is the question, even finding a serial card these days. The port setup on the NC machine should be in that machine's documentation.
HTH
Keith
 
A shop I used to work at the Kia had the card reader inside the cabinet on the back on the computer. Can't help you with the adapter. I was a bit of a pita, but it still worked.

Donovan from Wisconsin
 
You will probably need a program to connect with on the serial port. You are dealing with older technology.
 
Are you familiar with the Practical Machinist message boards?

LOTS of knowledge over there, and there's even a CNC-specific Forum.
Practical
 
I think you need to find a manual for the Fanuc device. It should explain what you can do through the serial port and what software you may need.
Most modern PC's do not have a serial port, but you can use a USB to serial converter (my latest one came from Radio Shack).
RS-232 may be nearly obsolete, but it is still used in new devices. We still purchase new laser distance measuring devices that use RS-232.
Good luck.
 
The Compact Flash cards emulate MS-DOS file systems, typically FAT32. I'm not familiar with your Fanuc controller, but I'm pretty confident it has no way of reading a FAT filesystem, even if there was some way to connect a card reader to the controller. You have to transfer the file from a PC over RS-232.

Making the physical connection is simple: Get an RS-232 to USB adapter and a RS-232 cable, plus an adapter if necessary, and hook the PC up to the controller. Ideally you'll have the original serial cable from the controller, because not all RS-232 cables are wired the same. Your controller might very well need a "null modem" cable, which criss-crosses the data lines so two PCs can communicate over a cable. In fact, I'd say that's the most likely configuration. If you can't find a null modem cable, it's easy enough to make one yourself; google "null modem serial cable" and you can find plenty of wiring diagrams.

It's been a while since I messed with RS-232 on a Windows PC, but I think you can figure out from the Control Panel which COM port your USB convertor is set to use. You kind of need to know that to go much further, because communications software wants to know which port to use.

The tricky part is going to be talking to the controller. Although it's fairly simple to send serial data over RS-232, transferring files requires a file transfer protocol, and you need to know which protocol the controller understands. Kermit and Xmodem are a couple of common protocols. Whatever the controller uses, it needs to be running on the PC.

Unless you have software on your PC specifically for talking to the Fanuc controller, you'll need a serial communications software application. Back in the days of modem-based bulletin boards, there were dozens of such freeware tools. Today there are still plenty. These tools have the ability to emulate computer terminals and also implement file transfer protocols. Kermit (the application, not the protocol) is one such tool.

There are a lot of gotchas to getting two RS-232 devices to talk, and unless you have some documentation to work with it can be a real challenge. Good luck.
 
Hey Steve.

I have a similar issue with a sign cutter that is a bit elderly and runs on a serial. I have tried numerous adapters to try and convert from usb to serial and most all would run a printer but not a dxf file to run the machine.

One way to get around the problem is to get an older pc with a serial output and network it with whatever you are creating the files with. You should be able to output through the older PC to your machine.

This worked for me, actual mileage may vary.

Good luck,

Brad
 
Brad, if you were using a desktop PC, did you try a serial port PCI card? I suspect the USB adapters you tried were overflowing the input buffer on your cutter when you tried to transfer a large file. USB is very fast compared to RS-232 and has to be throttled down to run at serial port speeds.
 

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