14/04/2023 By admin Off

What is Typical MDI Commands on CNC Machines?

MDI (Manual Data Input) commands are used in CNC (Computer Numerical Control) machines to directly input commands and data into the machine’s control system during manual operation. MDI commands allow operators to control the machine in real-time by manually entering commands through the control panel or keyboard. Here are some typical MDI commands commonly used on CNC machines:

  1. G0/G00 – Rapid positioning: This command moves the machine tool rapidly to a specified position without cutting or shaping the workpiece. It is used for fast tool movements to quickly move the tool to the next machining location.
  2. G1/G01 – Linear interpolation: This command specifies a linear feed rate for the machine tool to move the tool along a straight line path in a controlled manner. It is used for cutting or shaping the workpiece along a straight line, such as for facing or turning operations.
  3. G2/G02/G3/G03 – Circular interpolation: These commands specify a circular path for the machine tool to move the tool in a controlled manner. G2 is used for clockwise circular interpolation, while G3 is used for counterclockwise circular interpolation. These commands are used for cutting or shaping the workpiece along circular paths, such as for threading or contouring operations.
  4. G4/G04 – Dwell: This command pauses the machine tool for a specified duration, allowing for time-based operations, such as waiting for coolant to be applied or for chips to clear.
  5. G20/G21 – Units selection: These commands specify the units of measurement for the machining operation. G20 is used for inches, while G21 is used for millimeters. These commands determine the measurement system for inputting and interpreting the dimensions in the CNC program.
  6. G28/G30 – Return to reference point: These commands instruct the machine tool to move to a predefined reference point, which is typically a home position or a reference position on the machine. G28 is used for automatic reference point return, while G30 is used for single-axis reference point return.
  7. G40/G41/G42 – Tool radius compensation: These commands specify tool radius compensation for machining operations. G40 cancels tool radius compensation, G41 activates tool radius compensation to the left of the tool path, and G42 activates tool radius compensation to the right of the tool path. These commands are used to compensate for the tool geometry during cutting or shaping operations.
  8. G90/G91 – Distance mode selection: These commands specify the distance mode for interpreting the CNC program. G90 is used for absolute distance mode, where all positions are measured from a predefined zero point, while G91 is used for incremental distance mode, where positions are measured relative to the current position.
  9. M3/M03 – Spindle start clockwise: This command starts the spindle rotation in a clockwise direction, typically used for machining operations that require cutting with a rotating spindle.
  10. M4/M04 – Spindle start counterclockwise: This command starts the spindle rotation in a counterclockwise direction, typically used for machining operations that require cutting with a counterclockwise rotating spindle.
  11. M5/M05 – Spindle stop: This command stops the spindle rotation.
  12. M6/M06 – Tool change: This command initiates an automatic tool change operation, allowing for the changing of cutting tools on the machine.

These are some of the typical MDI commands used in CNC machines. It’s important to note that the exact set of MDI commands may vary depending on the specific machine, controller, and machining operation being performed. It’s crucial to consult the machine’s documentation and follow the machine manufacturer’s recommendations and best practices for using MDI commands on CNC machines.