Block skip 

In CNC programming, block skip is a feature that allows specific blocks (lines) of the program to be bypassed or skipped during execution. This is particularly useful when you want to temporarily disable certain parts of the program without deleting them entirely. For example, you might use block skip to jump over tool changes, probing routines, or other operations that are not needed for a particular run.

The sign of skipping or suppression of blocks “/” can be used at any convenient position in a block, i.e. even in the middle of the block.

How Block skip Works:

1. Indicator for Block Skip: In most CNC machines, a special character (commonly a slash /) at the beginning of a line indicates that the block should be skipped.

• Example: /G01 X100 Y50 F100 This line will be skipped during program execution.

2. Execution Behavior: When the CNC controller encounters a block marked with the jump indicator, it ignores that block and moves on to the next one.
3. Use Cases:

• Skipping tool change commands during a dry run.
• Ignoring probing sequences if the machine is already calibrated.
• Temporarily disabling certain movements or operations without modifying the program permanently.

4. Enabling/Disabling block jump:

• Some CNC controllers have a Block Delete Mode or jump a block Mode that must be enabled in the machine’s control panel for the jump functionality to work.
• If this mode is disabled, the machine will execute all blocks, including those marked with the skip indicator.

Block skip Example in CNC Program :

N10 G00 X0 Y0 Z0 (Move to origin)
N20 /G01 Z-5 F50 (Drill hole - this block will be skipped)
N30 G00 Z5 (Retract)
N40 G01 X50 Y50 F100 (Move to new position)

• In this example, if jump a block is enabled, the machine will ignore the drilling operation (N20) and proceed directly to N30.

Important Notes :

• The exact syntax and behavior of jump a block can vary depending on the CNC controller (e.g., Fanuc, Haas, Siemens, etc.). Always refer to your machine’s manual for specifics.
• Ensure that jump a block is used carefully, as skipping critical blocks could lead to unintended consequences, such as collisions or incomplete machining.

By using block skip effectively, you can streamline your CNC programs and adapt them dynamically to different machining scenarios.