The CNC Program – Commanding The Machine

Hurco Training Class Room

Almost all present CNC program controls use a word address arrangement for programming. The only exclusions to this are certain conversational controls. By the word address format, we indicate that the CNC program is made of sentence-like commands.

Each command is fabricated of CNC words. Each CNC word has a letter address and an arithmetical value. The letter address (X, Y, Z, etc.) tells the control the kind of word and the mathematical value tells the control the value of the word. Cast-off like words and sentences in the English language versus in a CNC command tell the CNC machine what we are requesting to do at the current time.

One very good analogy to what happens in a CNC program is found in any step-by-step instructions. Say, for instance, you have some visitors coming from out of town to visit your business. You need to write down directions to get from the local airport to your business.

To do so, you must first be able to visualize the path from the airport to your business. You will then, in consecutive order, write down one direction at a time. The person following your directions will perform the first step and then go on to the next up until he or she reaches your business.

In a comparable manner, a manual CNC programmer should be able to imagine the machining operations that will occur during the execution of the program. Then and there, in step by step order, the computer programmer will give a set of commands that make the machine act accordingly.

However, slightly off the topic at hand, we wish to make a point about imagining. Just as the person giving travel directions MUST be able to imagine the path taken, so MUST the CNC computer operator be able to visualize the actions the CNC machine will be making BEFORE a program can be successfully established.

Without this visualization capability, the programmer will not be able to develop the movements in the program properly. This is one reason why machinists make the best CNC users. A knowledgeable operator should be able to easily imagine any machining operation taking place.

Just as each brief travel instruction will be made up of one sentence, so will each direction given within a CNC program be made up of one command.  While the travel instruction sentence is made up of words (in English), so is the CNC command made of CNC words (in CNC language).