--- title: "Fadal Format 1 vs Format 2 G-Code: The Switch That Decides" description: "Fadal controls run two G-code formats: Format 1, the Fadal-native conventions, and Format 2, the Fanuc-compatible mode. Which one a machine is in decides everything." url: https://gcodepractice.com/journal/fadal-format-1-vs-format-2-g-code/ canonical: https://gcodepractice.com/journal/fadal-format-1-vs-format-2-g-code/ author: "Lawrence Arya" authorUrl: https://www.linkedin.com/in/vibecoding/ published: 2026-06-07 updated: 2026-06-07 category: "Code reference" tags: ["fadal", "format 1", "format 2", "legacy machines"] lang: en --- # Fadal Format 1 vs Format 2 G-Code: The Switch That Decides > **TL;DR** Fadal's legacy VMC controls carry two selectable G-code formats: Format 1, the original Fadal-native conventions, and Format 2, the Fanuc-compatible mode added so posted programs and Fanuc-trained machinists could work normally, and the format setting decides how the control reads programs, so it is the first thing to establish on any Fadal. The working rules: identify the active format before reading or loading anything, run Format 2 for posted CAM work and portability unless shop history says otherwise, and treat inherited Fadal programs as format-stamped, a Format 1 program read under Format 2 rules misbehaves in exactly the quiet ways dialect mismatches always do. Fadal VMCs earned their place in American job shops by being affordable, repairable, and everywhere, and their controls carry a feature that still defines every programming conversation about them: two selectable G-code formats. Format 1 is Fadal's original native rulebook; Format 2 is the Fanuc-compatible mode added as the industry standardized around Fanuc-shaped code. One setting, two interpretations, and the first question on any Fadal is always the same: which format is this control in right now? ## Why a machine would carry two rulebooks The history explains the design. Fadal built its conventions early, its own code interpretations, its own defaults, and a large installed base learned them, wrote programs in them, and built shop documentation around them. Meanwhile the wider world consolidated on Fanuc-shaped code: CAM posts, training, and the [portable core](https://linuxcnc.org/docs/html/gcode/g-code.html) all assumed it. Format 2 was the bridge, full Fanuc-style interpretation on the same iron, and the toggle preserved the installed base instead of orphaning it. The result is the same lesson the [SYIL control question](/journal/syil-x7-fanuc-controller-g-code-list/) teaches at the machine level and Fadal teaches at the settings level: the machine's name does not tell you its dialect; its configuration does. ## The two formats, practically | Question | Format 1 | Format 2 | | --- | --- | --- | | What it is | Fadal's native conventions | The Fanuc-compatible mode | | Who reads it fluently | Fadal-trained operators, legacy programs | Anyone from the Fanuc-shaped world | | CAM posting | Needs the Format 1 post | Standard Fadal/Fanuc-style posts | | Inherited programs | Decades of them exist | The portable default | | The right choice | Where shop history demands it | Most modern situations | The portability column decides for most shops today: Format 2 lets posted work, hired machinists, and [standard fluency](/journal/mach3-g-code-list-vs-fanuc/) function without translation. Format 1 persists honestly where decades of proven programs and trained hands make switching costlier than staying, and the strong rule is consistency either way: pick per machine, label the choice on the control where the next person sees it, and stop toggling, because the toggle is exactly where the failure mode lives. ## The failure mode, and the stamp habit A program written under one format and run under the other fails the way [dialect mismatches always fail](/journal/planetcnc-vs-mach3-g-code-compatibility/): quietly where the rulebooks disagree, loudly where the parser objects, and confusingly everywhere else. On a machine whose setting can change, the protection is treating every program as format-stamped: a comment block declaring (FORMAT 2) at the top costs nothing and converts the inherited-program gamble into a checklist line, the [comment-the-assumptions craft](/journal/how-to-add-comments-in-g-code-parentheses/) applied to the machine's most consequential setting. Inherited Fadal programs without the stamp get identified before they run, by provenance, by reading their conventions, or by asking the only person who remembers, and then stamped for the next decade. The verification habit completes the protection: on an unfamiliar Fadal, confirm the active format from the control's settings rather than from a label that may have outlived its truth, and run one known-good program of the expected format in single block before trusting the configuration story. Five minutes, once per machine encounter, and the format question stops being a gamble. ## Living with a Fadal now The machines remain common because the support ecosystem stayed alive: [parts and documentation suppliers](https://fadalcnc.com/) and the [marque itself](https://www.fadal.com/) keep them running, which keeps them entering garages and small shops at prices that make the format quirk worth learning. The skills math is friendly: a Fadal in Format 2 is a Fanuc-shaped classroom, the universal core applies untouched, and the free 60-second rounds on the [G-code practice page](/g-code-practice/) drill exactly the vocabulary that reads on it. The Fadal-specific layer, the format system, the conventions, the folklore, is an afternoon with the manual and the shop's elders, and the first lesson is the one this page opened with: before anything else, find out which rulebook the control is reading from today. ## Sources - [FadalCNC: parts and support](https://fadalcnc.com/) - [Fadal: official site](https://www.fadal.com/) - [LinuxCNC: G-code reference](https://linuxcnc.org/docs/html/gcode/g-code.html) ## Frequently asked questions ### What is the difference between Fadal Format 1 and Format 2? Two selectable rulebooks on one control: Format 1 is Fadal's original native conventions, Format 2 the Fanuc-compatible mode added for posted programs and Fanuc-trained habits. The active format decides how the control reads everything. ### Which Fadal format should I use? Format 2 for most modern situations: CAM posts target it and standard fluency reads it. Format 1 where shop history demands it. Pick per machine, label it, stop switching. ### What happens if you run a program written for the other format? Quiet dialect-mismatch failures: codes reinterpreted under the wrong conventions, sometimes an alarm, sometimes a wrong move that parses fine. Treat inherited programs as format-stamped, and stamp them in a comment. ### Are Fadal machines still worth learning on? Yes: the used market keeps them common, the support ecosystem keeps them running, and a Format 2 Fadal is a Fanuc-shaped classroom where the universal core applies untouched. --- Source: https://gcodepractice.com/journal/fadal-format-1-vs-format-2-g-code/ Author: Lawrence Arya — https://www.linkedin.com/in/vibecoding/