Linux to rs232 controller?

Does any one know a way to use the Linux software with an older Tecnos controller?  I have year 2000 Woodmiser router with a windows vista PC connected to the Tecnos control via rs232 cord.   I am attempting to upgrade to modern Linux touch screen and software.  I was going to get a Mesa 7I97 board, but I would have to track down every wire that is currently correctly hooked to this existing control.  But maybe the rs232 hook up is just too obsolete or not compatible to Linux and the Mesa board is the best long term fix ? 

I thought the first post was under the wrong category. Sorry. I am new here.

I don't think it will work to use Linuxcnc as the PC front-end for your old control. Linuxcnc is a control in itself. To retrofit your machine you will be using a PC running Linuxcnc to replace that whole silver box you've pictured above. You will need to figure out what kind of control signals were used by your old system, then you will be able to purchase the right interface hardware to duplicate the old system with Linuxcnc. Most likely it will be analog controlled servos, but could be step/dir or some other digital com between the control and the drives.

If the machine had a windows PC front end for the user interface, then it probably doesn't do (or need to do) serial port DNC. But if I'm misunderstanding the situation one program I like for DNC is NCPlot. It isn't free or Linux but it has some very nice features, especially for running older Fanuc hardware.

Looks like with NCPLot I would still need a Fanuc or other control. This machine has a windows vista based proprietary control that I am trying to get away from. I understand I can use Linux and a separate Mesa board. I was just wondering if I could use the same Linux computer but tap into the existing "board" with the rs232 cord because it is already wired up instead of switching to the Mesa card. But I assume the big issue would still be to know were all the i/o are going from the rs232 box that I currently have.

Unfortunately Linuxcnc isn't going to do that for you. It would be about the same amount of work to build your own user interface for the old control from scratch on a Linux PC, as it would be to make one of Linuxcnc's UIs communicate with the old control.

PS, pretty sure the old system's Vista PC is only handling the User Interface, and loading/storing the milling code files, the main part of the control (motion planning and I/O) is probably all done in that silver box.  And that is the part that Linuxcnc needs to handle it's self for it to work.

Thanks for the help. It does look like the Mesa 7i97 is my best bet (correct me if I am wrong). .....and learning to do it with the Mesa card is probably good to learn for my next retrofit anyway.