G&M Code vs. Conversational Programming  

When you get down to the nitty gritty, there are MANY ways to program a CNC machine. Deciding which one is the best for you depends on a wide variety of factors. The following options are available.  

  1. CAM (Computer Aided Manufacturing) software programming (such as Mastercam) 
  2. G&M Code programming  
  3. Conversational programming  
  4. Macro programming  

 So, what are all of these?  

CAM Software Programming 

 Having CAM software such as Mastercam is very helpful. Oftentimes, you can use 3D models and blueprints to not only create the program but also simulate and verify the program. CNC programmers access CAM software through a computer (either at the machine or in an engineering/programming office). 

G&M Code Programming 

List of G&M Codes for machining

G&M Code programming is done on the machine. Rather than working on a computer or laptop, CNC programming occurs within the controller screen. 

G&M Code programming uses a series of codes, either G-codes or M-codes.  

  • G-code stands for Geometric Code.  
  • These codes direct a CNC machine to perform the operations needed to create geometries and profiles in the material.  
  • An example of a G-code is G84 which directs the machine toward a tapping cycle.  
  • M-code stands for Machine Code or Miscellaneous Code. 
  • These codes direct the functions of the actual machine rather than the geometry or feature requirements.  
  • An example of an M-code is M05 which directs the machine to stop the spindle.  

Conversational Programming 

Conversational programming is a type of programming that uses prompts. The prompts are questions asked of the programmer or machinist. These prompts gather answers regarding part geometry, type of material or metal, as well as the tooling needed to complete the desired features. In summary, someone performing conversational programming is answering questions which allows the machine to create a program from which the machine will operate.  

G&M Code Programming vs. Conversational Programming 

So, what’s the difference between the two? A fitting example is the process of giving someone directions to an agreed upon location.  

  • In G&M code programming, directions are given in a step-by-step nature. If someone needs to get to the local grocery store, as a direction teller you will share all the lefts and rights that need to be taken, the stores that you’ll pass by, the miles to travel, etc.  
  • In conversational programming, directions are less specific. In this example, as a direction teller you will tell someone the cross streets at which the grocery store is located (I.e., Main Street and First Avenue). However, the traveler will determine the best route needed to get to Main Street and First Avenue. 

Macro Programming 

metal drill bit make holes in aluminium radiator on industrial drilling machine. Metal work industry.

Macro programming is done when there are repetitive operations on a part but different variables for each operation. In this type of programming, the main operation (or repetitive operation) is programmed via CAM, G&M, or Conversational programming. Macro programming creates a “sub program” to alter that main program.  

  • An example would be a part that needs multiple holes drilled but the holes are of different depths. Typically, feed rates change according to depth. Therefore, you program the machine to “drill a hole” as your main operation but the macro programming within that program details the depth and the feed rate for each individual hole. 

You now have a tight grasp on what differentiates these types of programming. It’s easy to see why they were all created. Each programming style lends itself to greater job efficiency depending on the task at hand. Perhaps you’ve been searching for a better way to program the task of hole drilling in a project you have. You now know that Macro may be the way to go. 

If you find that you have a propensity for any of these programming styles, and need employment, don’t hesitate to reach out to our hiring team via this website! We’d love to have you join our team of talented technicians.