What does the command "G28" do in G-code?

The command "G28" in G-code is specifically designed to move the machine to its home position. This is an important function in CNC milling operations, as returning to the home position ensures that the machine is in a known location, which is essential for proper setup, referencing tools, and executing new programs.

The home position generally refers to a defined point on the machine, typically at the minimum limits of travel in the machine's axes. By utilizing this command, operators can ensure that the axes return to their starting point, which is especially important after machining operations to safely clear the workspace and prepare for the next task.

In contrast, starting the milling process, pausing, or stopping all machine functions are covered by different commands and are not functions of G28. Each G-code command serves a specific purpose within the CNC programming environment, making it essential to use the correct command for the desired action.