To translate Marlin 3D-printer messages quickly, identify the human-readable text carried by specific commands such as M117, preserve the machine command and its parameters, and verify the message on the actual supported LCD or host interface. Never run edited G-code on a printer merely to check language. A translation-only review should compare the operational commands before and after editing, then use controlled simulation or an approved nonprinting test procedure.
People searching for Marlin G-code translation, M117 LCD message localization, or 3D printer operator prompt QA need to distinguish a status display from an instruction that changes machine behavior. M117 sets an LCD status message when supported; M118 sends serial text to a host and can carry host-interpreted action syntax. Some pause commands can carry messages too. A translator must not treat an entire G-code line as editable prose.
This guide uses the official Marlin documentation for M117, M118 and M0/M1, with practical safeguards for firmware variation, character support, message length, pause states, safety warnings and recovery. It provides a small nonmotion fixture and a changed-context exercise. The example text is not a universal firmware localization package or a recommendation to execute unfamiliar print files; actual command behavior depends on the printer build, connected host and hardware configuration.
Establish the permitted editing area
G-code is a command stream, not an article
A sliced print file can contain movement instructions, temperature commands, extrusion changes, comments and human-facing status messages. Although many lines are readable, their role is operational. Translating words everywhere in the file can corrupt coordinates, parameter letters, tool selections or host markers. Begin by treating the complete file as executable machine input, with an explicit allowlist of editable message portions.
An operator may want English preparation prompts changed into Malay for a training lab. The safe scope is not “translate the file”; it is “translate reviewed LCD or host text in approved commands.” The motion path, temperatures, extrusion amounts and pause conditions belong to the validated print job. Such values must not be changed by the linguistic workflow.
Produce an inventory with command, line location, original message, target locale, output channel and owner. Include a field indicating whether text is displayed to an operator or interpreted by host software. Review the inventory against the exact firmware documentation before making any edits, because similar-looking strings can have different effects.
Comments and messages are different categories
A G-code comment may be intended for human maintainers, while a command’s trailing string may appear on an LCD or serial console. Comments are often marked by a semicolon in common G-code dialects, but parsing details depend on the source and firmware. A translation pipeline must know whether it is editing an explanatory comment, a display message or a control command.
A source may contain a comment saying “check filament” immediately before a heater instruction. Changing the comment leaves the command untouched, but may still mislead an operator if its warning loses urgency. Editing an M117 status string affects what the printer tries to display. Those should have separate review categories and acceptance checks.
Never assume semicolon-delimited text is harmless when host tools, preprocessors or custom macros are involved. Inspect the actual toolchain and preserve the executable prefix byte-for-byte where practical. If the production parser is unfamiliar, block the change until the printer maintainer clarifies which parts are safe to edit.
Understand the M117 display surface
M117 changes a status message, not the print plan
Marlin documents M117 as setting the LCD message line, with an optional string following the command. It requires appropriate LCD support, and displayed behavior depends on controller settings. The command does not itself move axes, heat the nozzle or pause the machine. These distinctions matter when translating prompts that appear during a print.
Consider M117 Preparing lesson model. The text after the command is a candidate for translation, while M117 must remain unchanged. A local phrase should communicate the same status and fit the available display. If a translator adds a line break or another G-code command, the edit has crossed the boundary from language to machine input.
Check whether the printer actually has a compatible LCD and whether the firmware supports the command. A well-formed M117 line may produce no visible result on a headless setup. Record that as a hardware or configuration limitation, not a failure of the translated wording.
Status words must match actual machine state
A status message saying “ready to remove” can be dangerous if the printer remains hot or moving. Translating “cooling” as “cooled” changes a process into a completed condition. The correct target phrase must preserve tense and any conditions affecting safe operator action, not merely retain the topic of the source sentence.
A teaching lab may display “Print finished; allow cooling before removal.” A shortened translation saying “Remove model” erases the cooling instruction and could encourage contact with a hot surface. The operator and printer maintainer should review the meaning against the actual stage of the job, because a display sentence can influence physical behavior.
Build a state ledger identifying when each message appears and what the hardware may still be doing. Confirm translated text with the person who owns the print procedure. Do not invent safety assurances or assume the display text itself enforces a safe physical state.
Distinguish host serial output
M118 messages have a different destination
Marlin’s M118 sends text to a connected host through serial communication. Parameters such as E1, A1 and P can affect how a host receives or interprets the line. The message may be consumed by software rather than shown on the printer LCD, so a successful translation must be checked in the host application.
A lab using a serial console might send a status note through M118 E1 P0. Translate the trailing human text if the host treats it as a display message, but preserve the recognized parameters and port choice. An apparent abbreviation in that prefix is not shorthand for an English word; it is command syntax.
Record the host software name and version, not just the firmware. A target string can be correct but invisible if the host filters echo messages or uses a different port. The acceptance test should say which interface must show the message and what exact action, if any, is expected.
Host-action syntax is not ordinary prose
Marlin documents an A1 parameter that can add a // prefix for host actions, and its example includes action:cancel. A host may interpret that text as an instruction rather than a conversational message. Replacing it with translated words can break the host action or alter control behavior in a way the translator did not intend.
Imagine a G-code line intended to tell a host to cancel a print. A translator sees action:cancel and replaces cancel with a local-language verb. The resulting line may no longer be recognized by host software, while a person looking at the file thinks the command is clearer. That is not a successful translation.
Classify any host action, reserved prefix or plugin command as protected technical syntax. Translate only separately identified human-facing text. If a host’s action mechanism or syntax differs from Marlin’s examples, consult its own documentation and test in a safe environment before approval.
Pause messages need operational review
M0 and M1 are more than labels
Marlin documents M0 as an unconditional stop-and-wait command, with M1 as a deprecated alias. An optional message may appear after timing parameters. Unlike M117, the command has an operational effect. Translating its text while ignoring the pause behavior can produce a misleading training guide or accidentally encourage unsafe testing on real hardware.
A line such as M0 Change filament is not merely a caption. It asks the configured printer to pause and wait for continuation, subject to firmware conditions. A target-language version must preserve the intended prompt and must not alter timer options, parameter order or command selection. Testing it can interrupt a physical print.
Restrict testing to a controlled setup approved by the printer maintainer, preferably an offline parser and a nonprinting demonstration where possible. If the firmware lacks the required LCD configuration, the command may be ignored; the team should document this limit rather than claim that every translated pause works on all printers.
Timeout parameters are safety-relevant values
Marlin describes P as a pause timeout in milliseconds and S as seconds for M0/M1. Where both appear, the documentation notes that S takes precedence. These numeric parameters are not translatable units inside a sentence. Editing them to fit a local phrase may shorten or lengthen a pause with unexpected machine consequences.
Suppose a translator changes S30 to S300 after interpreting it as part of a sentence. The pause duration has changed by a factor of ten, and the job no longer follows the verified procedure. A review script should freeze command names and numeric parameters while allowing only approved message spans to differ.
Record the original and edited executable parameter sequences and compare them mechanically. A human reviewer can then focus on whether the message tells the operator what to do, without being responsible for reverse-engineering the printer’s pause timing or motion behavior.
Build a safe fixture for offline review
Use message-only examples before touching sliced jobs
The small fixture below contains only M117 and M118 message lines, not heaters, extrusion or movement commands. It is for text inspection and parser demonstrations; do not treat it as a portable print program. A real printer may have different firmware features, LCD character support and host handling.
A team could translate “Check the build plate” for a local operator handbook, keeping M117 fixed. The M118 line is an independent host-console message whose E1 and P0 parameters must also stay fixed. The target version should pass a diff that extracts and compares those command prefixes.
Use source and target files with obvious synthetic identifiers and no actual print geometry. This limits the consequences of mistakes during QA. When validating on hardware is necessary, require an approved procedure that guarantees the device is in a safe state and does not turn the language review into an unsupervised machine operation.
; Illustrative messages only. No motion or heater instructions.
M117 Check the build plate
M118 E1 P0 Operator notice: check the plateCompare structure using an allowlisted parser
A simple text diff will show changed messages but may not reliably distinguish protected parameters from message text. Build a parser for the exact command forms the organization permits. Extract command names, supported parameters and message spans; compare protected parts, then pass only message text to translation QA.
For the example fixture, the baseline includes M117 and M118 with E1 and P0. A localized copy that changes E1 to A1 should fail automatically because that may change host semantics. A copy that preserves the prefix but changes ordinary message words can proceed to language review.
The parser itself needs test cases, including blank messages, unexpected whitespace, comments and unusual characters. If a line cannot be parsed safely, fail closed and refer it to the device maintainer. Do not silently assume unknown G-code words are additional natural-language content.
Display length and character support
LCD limits are hardware specific
Some Marlin-controlled devices have small character displays; others use graphical screens or different interfaces. A translation that is readable in a desktop preview may be clipped, wrapped awkwardly or replaced with empty squares on the actual LCD. There is no universal safe character count that applies to all hardware.
A brief English status message may become a long Mandarin or Tamil phrase in an operator guide, while the printer’s built-in font lacks the required glyphs. Transliteration or an approved shorter message may be necessary for a particular device, but that decision must be based on observed display support and local user comprehension.
Capture the controller type, firmware build and relevant language-font capabilities. Test the actual encoded message through the target interface. If the device cannot render the chosen script, report the limitation explicitly and do not substitute misleading abbreviations merely to force a visual fit.
Unicode length is not screen width
Code points, encoded bytes and visible glyph cells are different measures. A message may use one character that occupies two display cells, multiple code points that form one grapheme cluster, or punctuation with unusual rendering behavior. Counting Unicode characters alone will not ensure a line fits the printer’s display.
A target-language phrase with combined marks or full-width characters may look short in a text editor but occupy too much space on an LCD. The screen could clip the final safety word, which is often the most important part of a warning. Test with actual font and layout behavior, not a guessed string-length threshold.
If the display cannot show the complete message, produce an owner-approved short form that retains the action and warning. Keep a full description in an operator guide or host interface where possible. Record which surface receives which variant so future reviewers do not mistake the short form for the only approved translation.
Handle encoding and punctuation deliberately
Encoded text may not survive the full toolchain
A slicer, file-transfer utility, SD card workflow and printer firmware can interpret text differently. Even if a file is UTF-8, the display may support only a limited character set. The translation process should test the complete route from exported file to visible interface rather than claiming that saving in UTF-8 guarantees correct display.
A learner copies a translated M117 line from a word processor and introduces curly quotes or an invisible space. The text may display oddly, or a downstream parser may reject the character. The machine commands might remain intact while the message becomes confusing. Inspect encoded bytes when a failure is intermittent.
Keep an original copy, use a controlled plain-text editor and record expected encoding for the specific device setup. Use a reversible export and compare the executable G-code structure after transfer. Treat any character-set workaround as a documented device-specific adaptation, not a universal translation rule.
Colons and symbols can be meaningful to host software
A colon may be ordinary punctuation in a human message, but strings such as action:cancel may have special meaning to connected software. A translator must not assume that all text after a command prefix is free prose. The host interface may parse part of it to trigger an action.
An M118 line beginning with an action marker can be consumed by a plugin, whereas “Operator notice: check the plate” is intended as human information. These are different classes even though both contain text. A safe catalog labels them separately and grants translators access only to human-facing segments.
Add reserved-syntax tests based on the exact host implementation. If a new plugin introduces control markers, update the parser and translation permissions before editing those lines. Documentation from the printer firmware alone may not cover the behavior of every connected host tool.
Safe operations and human factors
Machine-state ambiguity must block release
An operator prompt is useful only if it describes the right action at the right stage. Messages like “safe,” “finished” and “ready” are especially sensitive because they can encourage physical interaction. Linguistic review should preserve qualifiers about heat, movement and power, and maintenance owners must confirm that the underlying process state is accurate.
A prompt telling someone to remove a part after cooling should not be shortened into “remove now.” A target-language reviewer who has never used the machine may miss the practical significance. Include the physical state of the printer and the intended operator step in the translation brief.
Test the wording against an approved operating procedure, not through trial-and-error with a live moving printer. If safety claims are unclear in the source, ask the device owner to rewrite them before translation. Language work should expose unsafe ambiguity, not hide it.
Accessibility needs more than an LCD message
An operator may have difficulty reading a small LCD because of eyesight, height, lighting or unfamiliar script. A localized message can improve comprehension but cannot make an inaccessible interface fully usable. Where supported, a host console, accessible operator guide or procedural checklist may provide complementary information.
In a school lab, a student might stand away from the printer while a supervisor monitors the print remotely. A translated LCD message may never be seen by the supervisor. Decide which role needs which information and distribute the message through approved channels without changing host command semantics.
Review prompts with representative operators under ordinary lighting and noise. Check whether critical warnings are visible in time for a person to respond. A correct translation delivered to the wrong surface is still an ineffective user experience.
Version and deployment governance
Marlin features depend on firmware configuration
A command documented by Marlin may require a feature enabled in the compiled firmware or a specific controller. The existence of official syntax does not mean every machine supports it. A language bundle validated on one printer should not be marketed as universally compatible with all Marlin devices.
A classroom has two printers with different LCD types. The same M117 phrase may appear correctly on one and not at all on the other. Record the firmware build, controller and host environment for both. Separate language defects from unsupported hardware features instead of guessing that the translation failed.
Maintain a compatibility matrix with tested printer configurations and message surfaces. If the second device lacks glyph support, that result is a deployment constraint requiring an approved alternative. The translated message file should not silently change printing parameters to compensate for missing display capability.
Slicers and macros may regenerate messages
A printed G-code file may be generated from a slicer profile containing start and end scripts. Editing a single output file can appear successful, but the next sliced model will regenerate the old English message. A durable workflow identifies the authoritative template or macro and manages its translation separately from generated jobs.
For a recurring classroom exercise, an instructor may want the same preparation prompt on every print. Updating the slicer template could be appropriate after validation, but a localization vendor should not have permission to modify unrelated motion or temperature lines in that template. Extract and reinsert approved message spans through controlled build steps.
Perform a clean export from the actual slicer profile and compare command prefixes with the previously verified baseline. Test two example print jobs to reveal whether the message appears at the correct lifecycle point. Document profile versions and avoid editing other people’s existing print files as part of a language-only task.
Diagnose and repair common failures
Good translation, blank LCD
If a message never appears, confirm hardware support, configuration and timing before rewriting the words. The M117 command might be unsupported or another status update may overwrite the display. The string itself could be valid, yet the user has no time to read it. The correct repair depends on what the device actually does.
Compare the same short source-language phrase and target phrase on the same printer under controlled conditions. If neither appears, investigate display support. If only the target fails, investigate characters, encoding and length. If both flash too quickly, review the status-message lifecycle with the device maintainer.
Do not insert an unapproved pause just to keep the translated text visible. Adding M0 changes machine behavior and could affect print quality or safety. A display-timing issue requires a planned device or workflow change, not covert manipulation by a translator.
Correct LCD, wrong host action
An M118 line may display a message but also participate in a host action mechanism. A translation that changes the action marker can stop the host from recognizing a command; an accidental insertion of a recognized marker can create an unintended action. That is a structural problem, not merely awkward wording.
Compare the original and localized line’s control prefix and protected host-action syntax. Test it in the exact host application under safe conditions, with destructive actions disabled or simulated when possible. Read the host’s own documented protocol, because firmware documentation may not describe every plugin or automation.
If the host unexpectedly cancels or resumes a job, stop language deployment and restore the verified version. Keep a trace of the line and host response for engineering review, but remove private user information or credentials from logs. Repair the parser boundary before resuming translation.
Changed-context transfer exercise with worked answer
Move from an LCD printer to a headless print farm
A school prepares a Mandarin M117 translation for one printer’s LCD. The next month, it migrates jobs to a headless print farm monitored through a network host and wants to reuse all messages unchanged. Is that a safe language-only substitution? No. The destination surface and host behavior have changed even if the print geometry is identical. The team must establish which messages are shown and which commands are interpreted in the new environment.
The worked answer begins with a read-only inventory of the print file and the source printer’s approved messages. Separate M117 LCD text from M118 serial text, M0 pause messages and host-action markers. Consult the host documentation to determine which notices appear in the farm dashboard, and keep all motion, heat and timing commands unchanged during translation review. If an M117 message is invisible on a headless device, do not assume it has reached an operator. A new communication mechanism may be needed through a separately approved systems change.
For a transfer test, use a synthetic message-only fixture and an offline parser to compare command syntax. In a controlled host simulation, confirm the notice is rendered without executing an action marker. Then verify the local-language explanation with a trained operator and inspect accessibility. The correct result may be that some messages need a new approved delivery channel, not that the translator should change executable G-code until the text appears.
Summary and review handoff
Marlin message localization is safe only when the team knows exactly which text is for people and which characters control machines or host integrations. M117 LCD text, M118 serial messages, M0 pauses and comments differ in effect. Protect executable commands and parameters, review safety-critical meanings and test display behavior on the intended hardware or host without unapproved printer operations.
A handoff should contain an allowlisted message inventory, preserved-command comparison, source and target phrases, printer and host compatibility notes, display-length observations, approved operator wording and a reversible deployment procedure. If a required display feature is unsupported, say so. A good translation cannot compensate for a missing controller, an unsafe pause design or an unknown host action syntax.
Further investigations for real printer fleets
A machine can display text from more than one source
The LCD status line may be updated by firmware, a slicer-generated M117 command or a host application that controls the printer. A translation team can approve a perfect phrase and still find it disappears because another component overwrites it. To diagnose this, identify every source authorized to update the status display and record which one owns each lifecycle message.
In a training lab, a custom end script may display “Printing complete,” followed almost immediately by a host status saying “Idle.” The translated message has no opportunity to help an operator. Do not change motion or pause commands solely to extend its visibility. Work with the device owner to define the intended message surface and persistence, then test the approved behavior. The linguistic workflow should report a delivery problem separately from the fidelity of the translated words.
Untrusted sliced files should not be treated as text documents
A G-code file supplied by an unknown source can contain operational instructions unrelated to any helpful message. Opening it for translation and then executing it is unsafe. The translator should use a read-only text extraction tool that exposes only allowlisted message spans and does not run the file. If the origin or integrity of the print job is uncertain, the printer maintainer must validate the program independently.
A downloaded demonstration file might contain an M117 message that looks harmless while other lines specify movement and heating operations. The presence of readable English does not mean the whole file is trusted. The offline QA process can compare messages and command signatures without connecting to hardware. A separate operational process must decide whether the print file itself is authorized. Keeping those responsibilities apart reduces the risk that language review becomes an accidental execution path.
Checksum and line-number formats can complicate editing
Some serial G-code workflows use numbered lines or checksums, and editing text in a way that changes transmitted bytes can invalidate them. The exact mechanism depends on the sender and firmware. A translator should not manually alter a numbered command stream without understanding how its transport metadata is generated, even if the only intended visible change is a short LCD message.
If a target message is substituted inside a checksummed transmission line, the sender must recalculate the checksum according to its own protocol before sending it. This is an engineering responsibility, not a translation task. Record whether the source under review is a raw sliced file, a host-generated stream or an edited macro template. A valid local-language sentence cannot compensate for a transport-layer mismatch that causes the printer to reject commands.
Machine defaults can hide a language fallback
A printer may show a firmware-generated status message when no M117 override is active. That message can come from a separate firmware translation system, not from the G-code file under review. Changing an M117 line therefore cannot localize the entire LCD interface, and inspecting only its output can confuse the team about which strings it actually owns.
For a class printer, a custom message may appear in Mandarin during preparation and then return to an English firmware menu after a status refresh. Document that behavior honestly. If the organization wants full interface localization, it must evaluate the relevant firmware language resources, fonts and controller support through a separate project. Do not promise comprehensive multilingual operation from a handful of translated G-code lines.
A short warning may need an operator reference code
Some small screens cannot fit the full explanation of a fault or preparation step. An approved abbreviation with a reference code can link the message to a printed or digital instruction card, but the code needs consistent meaning across languages. It must not resemble or collide with G-code syntax or a host action marker in the executable line.
A message such as “CHECK PLATE — P03” could refer to procedure P03 in the lab handbook, but that mapping is a local training convention, not an official Marlin requirement. Translate the explanatory words while keeping the reference code stable and verify the handbook is accessible to operators in the target language. Test whether staff understand the procedure without guessing. If not, the abbreviation is too obscure even though it fits on the screen.
Translation must not accidentally introduce newlines
A natural-language editor may insert line breaks when wrapping a long message. In a G-code file, a newline can end a command and make the following text look like a new instruction. The risk is greater when the copied string contains abbreviations or numbers that resemble a supported G-code command. Preserve each approved message on the expected single command line unless the maintainer explicitly supports another format.
Run a structural comparison of line counts and parsed commands, not just a spell-check. If a proposed target text needs two lines for clarity, consider a host interface or handbook capable of displaying the full message rather than inventing an unsupported multiline syntax. Reject any import that turns one allowlisted M117 line into several executable lines. The objective is readable operator guidance without changing the interpreter’s input structure.
Different slicer profiles can request different wording
A school might maintain profiles for PLA teaching models, specialized materials and supervised maintenance runs. A single generic message such as “ready to remove” can be unsafe or misleading across these profiles because the cooling and handling requirements differ. The translation catalog should include the operational context in which the source phrase is valid.
Before reusing a target phrase, compare the procedure and material conditions for each profile. A phrase that tells an operator to wait for the bed to cool should remain conditional if one profile requires longer handling precautions. The linguistic reviewer should ask the supervisor to confirm the instruction rather than inventing a material-specific safety value. A shared translation memory is useful for consistency, but it cannot verify that two print procedures have identical requirements.
Fault messages need separate ownership from normal status
A normal workflow message explains progress, while a fault prompt may require an immediate human response. Both may appear on the same LCD, but the translation should communicate different urgency and next steps. If the firmware itself generates a fault, its wording may be outside the G-code translation scope, and the team must not claim it is fixed by editing a sliced file.
Build a source inventory that distinguishes firmware faults, host alerts and custom M117 status lines. Test sample situations in approved nonhazardous simulations rather than deliberately provoking dangerous hardware faults. The reader should know whether a message is an informational update, a warning or an instruction. If the source lacks a clear recovery path, escalate it to the machine owner; a translator should not invent technical repair directions in another language.
Training instructions should not conflict with supervision
A translated message can be understandable yet inappropriate for pupils to act upon without an instructor. A command saying “change filament” may imply physical handling of a heated machine, depending on the printer and process. The school needs a procedure that states who may perform the action. Language QA should preserve that role boundary and flag source prompts that omit it.
For a supervised lab, the approved target phrase might tell a student to call the instructor rather than touch the mechanism. That change should come from the teacher or safety owner, not a freelance translator rewriting the procedure. Review the final wording beside the school’s operating rules. Test whether students know what to do when the message appears, but do not treat their confidence alone as proof that the operation is safe.
Localized files require reproducible provenance
A translation-only release should identify its parent sliced job or template, approved message catalog, device compatibility and reviewer. If a printer later behaves unexpectedly, staff need to know whether the motion commands changed or whether only the operator text was edited. File names like final_new_Chinese.gcode are not reliable provenance systems.
Store a hash of the approved source, an extract of protected commands and an exact record of allowed text substitutions. Regenerate the localized output through a controlled tool and compare it with the intended baseline. Archive the QA result alongside the translated file, not just in a private chat. This supports rollback and makes a future audit possible without claiming that a language checker certified the entire print program.
A print failure is not proof of a bad translation
If a localized G-code file is associated with a failed print, investigate the printer, material, slicer and command stream rather than concluding immediately that the local language caused the failure. It is equally wrong to assume the language edit was harmless without examining the diff. A rigorous process separates correlation from cause and compares operational invariants.
Use a known-good source file and test whether the protected command signature remains unchanged after localization. If it does, seek other evidence for the failure while still checking host action markers and file-transfer integrity. If the signature differs, halt deployment and determine how the import process modified executable content. This classification prevents misplaced blame and directs repairs to the right part of the toolchain.
Keep rollback simple enough for an operator to use
A release plan that requires manually editing dozens of G-code lines is difficult to reverse during a school session. Store the approved original and localized artifacts with unambiguous version labels and a controlled way to restore the source message catalog. The operator should not need to understand serialization rules or foreign-language punctuation to recover the known-good configuration.
Practice a rollback using a message-only fixture and confirm that the previous host console and LCD messages reappear under the documented environment. The printer maintainer should verify that no unrelated slicer profile or macro has changed. Record failures and improve the procedure before deployment. A reversible translation workflow is part of practical quality assurance, not evidence that physical machine safety has been certified by the text review.
Frequently asked questions
1. Does M117 start or pause a print?
No. Marlin documents M117 as setting an LCD status message when supported. It is not a motion or pause command.
2. Is M118 the same as M117?
No. M118 sends text to a connected serial host and may include special host-action syntax. Verify the exact receiving application.
3. May translators change `E1`, `A1` or `P0` in M118?
Not as language edits. These are command parameters or prefixes with operational meaning. Preserve them unless engineering separately approves a change.
4. Why is `action:cancel` not a translation target?
It can be a host-interpreted control marker, not a natural-language description. Changing it may break or alter the host action.
5. Is M0 text safe to test on a running print?
Do not assume so. M0 pauses and waits under applicable firmware conditions. Use an authorized controlled procedure or offline fixture.
6. Can every Marlin LCD display Mandarin or Tamil?
No universal capability can be assumed. Check the actual controller, font, firmware build, encoding and message length.
7. Should a translated safety message be shorter?
Only if an approved short form keeps every critical condition. Do not remove warnings merely to fit a small LCD.
8. Does UTF-8 guarantee that a message renders correctly?
No. Encoding is one part of the pipeline; firmware fonts and controller behavior may still limit displayed characters.
9. What is the safest diff for a translation-only release?
Compare parsed command names and protected parameters before and after editing, then review only permitted message spans. Reject unknown lines rather than guessing.
10. Why might a translated message never appear?
The device may lack required display support, the text may contain unsupported glyphs, or another status update may replace it. Diagnose hardware, encoding and timing separately.
Authoritative sources
- Marlin M117 — Set LCD Message
- Marlin M118 — Serial Print
- Marlin M0/M1 — Unconditional Stop
- Marlin G-code Index