CNC Machinist Calculator UltraHome › M-codes › Heidenhain TNC (ISO) › M120
M120 Look ahead for radius compensation
Heidenhain TNC (ISO) M-code · Mill
Pre-calculates the radius compensated contour for the next LA blocks, so the tool does not cut into undercuts or small steps.
Format
M120 LA
Addresses
| Address | What it does |
|---|---|
LA | Number of blocks to look ahead, up to 99 |
How it works
Modal. Cancel with R0 or G40, or M120 LA0.
Example program
N50 G01 G41 X+0 Y+10 F300 M120 LA2 *
N60 X+40 *
N70 G01 G40 X-10 *
N60 X+40 *
N70 G01 G40 X-10 *
Example is in inch. Check offsets and clearances first.
Watch out for
- Keep LA small. Large values slow block processing.
Related codes
M120 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| DMG Mori MAPPS (Fanuc) | External output |
| Mazak (EIA) | Measurement data print out |
| Centroid CNC12 Acorn | Open data file, overwrite |
Every M-code for Heidenhain TNC (ISO) in your pocket. The app has the full example programs, search by number or shop word, a line decoder and calculators for tapping, threading and drilling.
Open M120 in the app All Heidenhain TNC M-codes