The FANUC Series 0i / 30i milling dialect (ROBODRILL, 31i-B5)

DryRun's FANUC dialect follows these notes; in this version only the catalogue ROBODRILL uses it. They were written from the ROBODRILL operator's manual and the standard FANUC rules, not on a real control: rows marked [K] or [A] are not verified (user guide §7.13; the simulator's own table is in §6.4).

Research date: 2026-10-14. How a FANUC milling control reads G-code, which alarms it raises, and what DryRun's fanuc dialect does with each code. The machine is in 06-fanuc-robodrill-d21.md; the other dialects are in 03-ddcs-v41-dialect.md (DDCS V4.1) and 05-grbl-dialects.md (GRBL family).

Review 2026-10-14: the decisions of the review after this research are applied in the tables below: rapidMode defaults to "independent" (dog-leg), duplicate words take the last value (PS5074 only with 3403#6 AD2 = 1), G41/G42 and G65/G66 are listed as assumed, macro control flow stops the run, and "FANUC" is not offered in the Library editor in v1 (only the catalogue ROBODRILL uses the dialect). The "DryRun v1" columns say what the simulator does; the user guide §6.4 is the reference, §7.13 lists what is assumed.

0. Evidence levels and sources

• [OM] FANUC ROBODRILL α-DiA5 Operator's Manual B-85314EN/01, control Series 31i-B5: App. B (G-code list and modal groups), App. D (CNC alarm list with numbers and messages), §III-6 (tool change), §IV-2.7.3 (M codes), §37 (MANUAL GUIDE i templates). A text copy of the official manual (link in §8). This is the primary source here.
• [BR] FANUC ROBODRILL α-DiB Plus brochure: the list of standard and optional CNC functions.
• [K] Standard FANUC behaviour as documented in the Series 0i-F / 30i-B operator's manuals (B-64604EN, B-64484EN). Those manuals were not readable for this card; these rows are written from the well-known FANUC programming rules and must be checked against a real control (§6). Parameter numbers marked [K] are the usual ones and are not verified.
• [A] Assumed by me for the simulator.

Main finding. FANUC is the reference dialect the DDCS imitates ("comprehensive Fanuc G code set"), so most of the DDCS table and code already fit: modal groups, canned cycles with absolute R/Z and K repeats, G98/G99, G43 H, M98/M99 with O labels in one file, macro lines skipped. From the GRBL family it needs the alarm model: a FANUC control stops the program at the first block it cannot accept and shows a numbered alarm (PS0010 IMPROPER G-CODE), as GRBL stops on error:20. FANUC-specific work: the decimal-point rule, G54.1 P1–P48, G52, G28/G30 through an intermediate point to the reference positions, the ROBODRILL tool-change rules (M06 alarms, T without M06), PS/OT alarm wording.

1. Program format and words

1.1 The decimal point (the "X100" rule)

With parameter 3401#0 (DPI) = 0, the FANUC default, a length without a decimal point is in least input increments: on a metric control with IS-B (0.001 mm), X100 = 0.100 mm, X100. = 100 mm. With DPI = 1 ("calculator type") X100 = 100 mm [K; mfgrobots.com, §8]. F, S, T, H, D, M, K, L and the program number are integers either way; G04 P is in ms and takes no point; G04 X is seconds and takes one; G83 Q and G73 Q follow the length rule (Q2000 = 2 mm) [K]. The ROBODRILL manual tells the user to "Specify each value with a decimal point" in its own macro calls [OM §33, DDR M16 call], which matches DPI = 0. CAM posts for FANUC always write the point.

DryRun v1: a machine switch decimalPoint: "standard" | "calculator", default "standard". In standard mode an axis, I/J/K, R, Q or G04 X value without a point is scaled by 0.001 (inch: 0.0001) and the program gets one warning: X100 has no decimal point: read as 0.100 mm (FANUC parameter 3401#0 = 0); write X100. for 100 mm.

2. Code table

"Executed" = simulated. "Note" = runs, the Check lists a note. "Ignored" = the code is dropped with a warning, the rest of the line runs. "Skipped" = the line does not run (warning). "Alarm" = the control stops with that alarm: the line is not executed and the verdict is DO NOT RUN (as GRBL's rejected lines). Modal groups are from [OM] App. B; * = the state at power-on / reset.

2.1 G codes

2.2 M, T, S, F

2.3 Custom macro B

# variables, [ ] expressions, IF [..] GOTO n, WHILE [..] DO m … END m, #3000 = n (MESSAGE), G65 calls are standard on the ROBODRILL ("Custom macro" [BR]). Alarms exist for each (PS0112 ZERO DIVIDE, PS0114 ILLEGAL EXPRESSION FORMAT, PS0115 VARIABLE NO. OUT OF RANGE, PS0124 MISSING END STATEMENT, PS0126 ILLEGAL LOOP NUMBER, PS0127 DUPLICATE NC,MACRO STATEMENT, PS0128 ILLEGAL MACRO SEQUENCE NUMBER [OM] App. D).

v1: not executed; each line is sorted by its effect. Variable assignments (#100 = 5.) and #3006 messages are skipped with a note. An unconditional #3000 = n (MESSAGE) is the control's macro alarm. G65 / G66 calls are skipped and listed as assumed (macro P9810 not simulated (line 12); its motion is not checked); a probe call (an S word, or P9853) reads G54 set by probe on line 12 — the setup's G54 is assumed to match where the probe finds the stock. GOTO, IF … GOTO, WHILE … DO … END and any word with a # value stop the run there: macro not simulated — results after line 12 not checked. Probing and tool-measurement macros (O9xxx calls) are typical victims.

3. Alarm wording (what the Check prints)

FANUC shows PS<4 digits> <MESSAGE> [OM App. D: "PS"alarm number", e.g. PS0003]. DryRun prints the same, then a short cause: PS0010 IMPROPER G-CODE: G90.1 is not a FANUC code — the control stops here; the simulation goes on as if you continued. Messages are copied exactly from [OM] App. D:

Not used in v1: PS0224 ZERO RETURN NOT FINISHED (the simulation always starts at the reference position), EX alarms (machine-side: door, tool clamp, spindle without tool).

5. Machine switches for dialect: "fanuc"

6. Assumed but not verified (user guide §7.13)

1. T6 Duplicate words: the last value assumed (parameter 3403#6 AD2 = 0, the default); with AD2 = 1 the control raises PS5074 instead.
2. T7 G00 path: the non-linear dog-leg assumed (LRP = 0, the factory value; what the ROBODRILL ships with is not known); with LRP = 1 the rapid is a straight line. The real dog-leg is a rounded curve (acceleration).
3. T8 Arc tolerance (parameter 3410) assumed 0.005 mm.
4. T9 G73 retract (5114) and G83 clearance (5115) assumed 1 mm.
5. T10 M06 always goes to the Z reference; X/Y stay unless commanded on the same block (manual says so; post habits like G91 G28 Z0 before M06 are harmless).
6. T11 T without M06 is PS0043 on the ROBODRILL (the manual names the "DRILL-MATE ATC"); other FANUC machines with an arm-type ATC accept tool pre-selection.
7. T12 Lower case and ; mid-line.
8. T13 The decimal-point default (DPI = 0) on the owner's / user's control.
9. T14 M99 in the main program loops forever on the control; simulated once.
10. T15 Two codes of one group: last wins without an alarm (App. B note 4) — verify on a 0i-F, which may alarm.

7. Typical program (FANUC post, as the ROBODRILL manual's own example)

%
O0400 (FACE)
G91 G28 Z0
G00 G40 G49 G80 G90
G54 G28 X0 Y0 Z0          (G90: intermediate point = work zero — runs as written, with a note)
M06 T01
M03 S800
G00 X0 Y0
G00 G90 G43 Z1. H01
M08
G01 G90 Z-1. F600
X250.
Y-40.
X0
M05
G91 M09
G28 Z0 G49
M02
%

Program O400 in [OM] §I-1 (machining capability); the % and the comments are added.

8. Sources

• [OM] FANUC ROBODRILL α-DiA5 Operator's Manual B-85314EN/01 (Series 31i-B5), copy: https://pdfcoffee.com/b-85314en01-fanuc-robodrill-d21mia-operators-manual-pdf-free.html — App. B G codes (pp. 953–956), App. D alarm list (pp. 962 ff.), §III-6 tool change (pp. 198–200), §IV-2.7.3 M codes (pp. 156–158), §I-1 sample program O400.
• [BR] FANUC ROBODRILL α-DiB Plus series brochure, standard and optional specifications — https://www.fanucamerica.com/uploads/files/data-sheets/robodrill-alphadib-plus-series-brochure.pdf
• Decimal point parameter 3401#0: https://www.mfgrobots.com/Article/equipment/cnc/46531.html (secondary; the FANUC parameter manual B-64490EN / B-64610EN was not readable)
• [K] FANUC Series 30i/31i/32i-B operator's manual B-64484EN (an upload exists at https://www.slideshare.net/slideshow/b-64484-en03/15400136, not readable as text) and Series 0i-F B-64604EN: the sources to check every [K] row against.

Other controllers

The DDCS V4.1 dialect notes and GRBL 1.1 and grblHAL in DryRun.