In many cases, a CNC machine may be located a good distance away from the computer, or perhaps a number of machines are connected to a central computer. In either case, the last thing you want is machine operators running or shouting across the shop, or crowding around the computer.
If your CNC machines are based on a modern operating system, then they might be connected to your company’s Ethernet network and thus able to browse through a remote server’s files. In most cases though, the NC control just doesn’t have any networking capability and are unable to do anything like that.
One thing most CNC’s can do, however, is send and receive files via RS232. They can’t request files from computers, but they can send files to computers. So, what we can do is create a small program on the CNC, write our request into that file, and sent that file to the computer. As long as the computer, in this example running the software Predator DNC, is expecting such a file, it would see the incoming data, read the request, and complete whatever action was contained within. In this example, Predator DNC has been programmed to expect such simple file requests from pretty much any CNC as long as the CNC is capable of punching out a CNC program through the serial port.
Before you can use the server mode within Predator DNC, you need to set it up and enable it. We’ll explain that in a moment. First, we’ll give an example of what you can do with it. In our examples, we’ll describe usage with a machine like a FANUC because there are lots of other makes and models of CNC which adhere to the same ISO data standards. We can also show you a couple of alternatives, so you can adjust this method to suit other machines.
In the CNC control, we first create a small program using a program number that isn’t used by the machine. We call this program the Remote Request, because we use it to request a program from the PC remotely. Let’s use program number 7 as our Remote program (O7777). You can, of course, use any program number you want. In our example we want the PC to send program number 1234 into the machine. On a FANUC we’d create a small Remote program like this:-
That’s it: just those five lines. When you’re ready, send (“Punch”) the Remote Request to the computer and quickly switch the CNC into “Input” / ”Read” mode. When Predator DNC receives the request it opens the file, sees the command (LOAD) and the following text (1234) and knows that the CNC is waiting for program 1234. Predator DNC pulls the file from the machine’s default folder, loads it up, and sends it to the CNC.
Keep the Remote program stored on your CNC, so you can use it again. Next time you use it, just edit the text between the parentheses to request any other program.