M100 CNC Code: Beginner’s Guide to User-Defined M Functions

Welcome to our simple guide on the M100 CNC code. Whether you are new to CNC programming or an experienced machinist, understanding the M100 code is essential.

This guide will explain everything you need to know about this unit mode command—what it is, when to use it, and why it matters.

(Step-by-step.)

Key Takeaways

• M100 is a user-defined command that executes an external program, pausing the G-code file until the program exits.
• It outputs a digital signal, allowing control of external devices like contactors and air valves.
• M100 can pause the G-code file to perform tasks like tool changes or override spindle speed and feed rate.
• The code is used in CNC machines to control external events or equipment, and the output remains active even after issuing the RESET command.
• Configuring M100 codes requires a thorough understanding of their functionality to guarantee safe and efficient operation.

Understanding M100 CNC Code

When working with CNC machines, you’ll likely encounter the M100 code, a user-defined command that executes an external program, pausing the G-code file until the program exits.

This M code outputs a digital signal, allowing you to control external devices like contactors and air valves.

By using M100, you can pause the G-code file to perform tasks like tool changes or override spindle speed and feed rate.

In MDI mode, you can issue an M100 code to execute an external program, but be aware that the output will only shut down when you power down or issue an M110 code.

Properly understanding M100’s functionality and limitations is vital for safe operation and avoiding potential hazards.

Configuring M100/M110 Codes

Configuring M100/M110 codes requires a thorough understanding of their functionality to guarantee safe and efficient operation.

You’ll be working with digital outputs, specifically ON1 style M code outputs, to control external devices like contactors and air valves. M100 turns the output on, while M110 turns it off.

However, be aware that M100 doesn’t turn off with the RESET command, and neither does the E-Stop command. To shut down the output, you’ll need to power down or issue an M110 code in MDI mode.

This poses a safety concern, as E-Stop and RESET should terminate the event. To certify safe operation, you’ll need to reconfigure your setup, possibly by modifying the HAL file, to turn off the output when E-Stop or RESET is triggered.

To confirm safe operation, you’ll need to revalidate your setup, possibly by modifying the HAL file, to turn off the output when E-Stop or RESET is triggered.

M-Code Groups and Functions

You’ll use M-codes to control various aspects of your CNC machine, and these codes are grouped into three main categories.

The first group, Program Control Codes, governs the execution of your program, allowing you to start, stop, and modify the program as needed.

The other two groups, Spindle and Tool Control, and Coolant and Output Control, manage the machine’s physical components and auxiliary functions.

Program Control Codes

Across the spectrum of CNC machining, program control codes play a vital role in orchestrating the intricate dance of machine operations.

You’ll find that M100 and M110 codes are essential for controlling external devices, such as contactors and air valves, which are configured as ON1 style M code outputs. M100 turns the digital output on, while M110 turns it off, allowing you to regulate chip conveyors and optimize air usage.

These codes are part of the Group 4: Digital and Analog Output Control, which includes other codes for controlling digital and analog outputs. By combining M100 with other M codes, such as M2, M30, and M60, you can control program flow, spindle speed override, feed rate override, adaptive feed rate, and tool change, thereby playing a pivotal role in the machining process.

Spindle and Tool Control

Mastering spindle and tool control is essential in CNC machining, as it directly impacts the efficiency and accuracy of your operations.

You’ll use M-codes to control spindle direction, speed, and tool changes. M3 starts the spindle clockwise at the S speed, while M4 starts it counterclockwise. M5 stops the spindle, and M6 stops the spindle and prompts a tool change.

You can set the current tool number without a tool change using M61. During operations, you can override spindle speed and feed rate as needed.

Digital output controls can also be integrated into your machining process. Remember to use M5 to stop the spindle before changing tools to avoid damage or accidents, and be mindful of tool length offset during tool changes.

Coolant and Output Control

As you’ve learned to control spindle direction and speed, it’s now time to examine the role of coolant and output control in your CNC machining operations.

Coolant control is vital for machining processes, and M-codes help you achieve this. M7 turns mist coolant on, while M8 turns flood coolant on, and M9 turns both mist and flood coolant off.

In addition to coolant control, you can also control digital and analog outputs.

M62 and M63 turn digital outputs on and off, respectively, synchronized with motion. M64 and M65 do the same, but immediately. M66 allows you to wait on an input with a specified timeout.

For analog outputs, use M67 for synchronized and M68 for immediate control. By mastering these M-codes, you’ll have greater control over your CNC machining processes, which is essential.

Program Control and End

With program execution underway, you’re now concerned with controlling its flow and bringing it to a close. You need to oversee the program’s progress, make adjustments as needed, and ultimately terminate it.

Program Control	Description
M50 Feed Override	Temporarily changes the feed rate override
M51 Spindle Speed Override	Alters the spindle speed override control
M53 Feed Stop	Stops the feed motion
M52 Adaptive Feed	Enables adaptive feed functionality
M30 Program	Ends the program at the current block

You can use these codes to refine your program’s performance, such as implementing a tool change or adjusting the feed rate override. By strategically incorporating these commands, you can optimize your program’s efficiency and guarantee a smooth execution.

Spindle and Tool Control

You’ve optimized your program’s execution with the program control codes, now it’s time to focus on the spindle and tool control.

M3 and M4 codes are used to start the spindle, with M3 rotating it clockwise and M4 counterclockwise, both at the specified S speed.

You can use these codes with an S speed of zero, allowing the spindle to start turning when the speed is set above zero.

M5 stops the spindle, often used in conjunction with M3 and M4.

M6 not only stops the spindle but also prompts a tool change based on the last T-number programmed, without changing the tool length offset.

You can program a tool change to the tool already in the spindle, and the tool changer must be set up to perform the change.

Coolant and Output Control

Most CNC machining operations require some form of coolant control to guarantee efficient cutting and tool longevity.

You’ll use M7 to turn on mist coolant, M8 to turn on flood coolant, and M9 to turn both off.

For digital output control, you’ll use M62 to turn on synchronized output with motion, M63 to turn it off, M64 to turn it on immediately, and M65 to turn it off immediately.

These commands give you precise control over your coolant and output systems. By using these codes, you can certify your CNC machine operates efficiently and effectively.

With these commands, you’ll be able to synchronize your digital output with motion or turn it on/off immediately, giving you the flexibility you need for complex machining operations.

User-Defined Commands and Safety

You’ll find that M100 CNC code enables you to control external devices by executing an external program, but this feature raises important safety concerns.

As you integrate these user-defined commands into your safety protocol, it’s vital to ponder how to terminate the output safely.

You need to guarantee that your safety protocol integrates with the M100 code to prevent accidents and unexpected output activation.

External Device Control

When controlling external devices with M100 and M110 codes, it’s essential to understand their behavior and limitations to guarantee safe operation.

You’re working with digital output, so you need to know how to turn it on and off correctly. The M100 code turns on the digital output, but it won’t turn off with the RESET command.

Instead, you’ll need to issue an M110 code in MDI mode or power down the system. This raises safety concerns, especially since the E-Stop command doesn’t terminate the event and turn off the output as it should.

Since activating the output is under program control, terminating the program should deactivate it, especially when it controls external events or equipment. This current behavior doesn’t align with expected safety protocols, and a solution is needed to certify safe operation.

Safety Protocol Integration

To guarantee safe operation, integrating user-defined commands and safety protocols into M100/M110 code control is crucial. This integration certifies that your CNC machine operates safely and efficiently.

Command	Action
E-Stop	Terminate program and turn off output
RESET	Deactivate output and reset program control
M100	Activate digital output for external devices
Program Control	Activate output only when program is running
Safety Protocol	Configure M100/M110 codes to respond to E-Stop and RESET commands

CNC Codes Similar to M100

Movement and Positioning Codes

System Configuration

Tool Operations

Program Control

Drilling Cycles