1) An RS-232 cable connected directly to a PC RS-232 port, with the PC connected to the network, that, in turn, is connected to the Internet.

2) RS-232 cables connecting several CNC machines to an automatic (multitasking) switchbox connected to a PC on the network that is connected to the Internet. A variation of this approach uses a multitasking serial hub that is connected directly to the network (which is then connected to the Internet and controlled by a PC on the network).

3) An individual RS-232 cable connected to an Ethernet-to-RS-232 converter connected to a PC on the network that is connected to the Internet, or the Ethernet-to-RS-232 converter is connected directly to the network (which is then connected to the Internet and controlled by a PC on the network).

Connecting a legacy (RS-232) machine directly to the network, as given in the last example, involves these seemingly simple steps: Buy a single-port Ethernet-to-RS-232 converter, then attach that adapter to the factory-wide network by building a cable from the Ethernet adapter to the network jack. Next, build a custom CNC-style RS-232 cable from the Ethernet adapter to the machine tool. Configure the firmware on both sides of the adapter to communicate properly with the network as well as with the RS-232 port. Finally, set the parameters of the machine tool and your communication software on the network side. This approach will allow you to move the machine around and plug it into an Ethernet jack anywhere on the network, as long as you provide the necessary shop infrastructure to make it happen. If all goes well, you will be sending and receiving files between the machine tool and the Internet.

But what about monitoring the activity of the machine? The RS-232 port is available to send/receive part programs. Without substantial modifications to both the software and hardware of the system, you will not know what is going on with the machine (other than it is sending and receiving files).

Source: mmsonline.com

Normal Fanuc comms settings for your software -

Baud: 4800

Parity: Even

Data bits: 7

Stop bits: 1

The FIFO buffer setting in Windows is also important to prevent buffer overflows (alarm 087) on the CNC.

Typically your PC talks to your CNC machine via RS232 / Com ports, however newer machines / controls are now being supplied with windows operating systems & USB ports.

If using RS232 generally the cable required for most controls is a DB25 to 9 pin serial & a null modem adapter to fit on either end, these you can get from Maplin or any other electrical store.

This cable works on Fanuc & Mazak controllers & many more.

Less & less new laptops come with com ports nowadays as everything is moving over to USB so always check that your laptop has a com port as standard if looking to purchase one for your machines. I have just ordered 2 from Dell & both do still have com/rs232 ports. If your laptop doesnt have one you can use a PCMCIA to Serial adapter which seems to work with no problems.

You can also try a USB to serial adapter but people are having mixed success with such.