FANUC 0i-F stalled automatic cycles: why diagnosis 0 is not the old 000–015 table
Matching diagnosis numbers do not guarantee matching meanings. Comparing the 0i-C and 0i-F manufacturer manuals clarifies internal-state entries, speed-arrival waits and in-position checks without treating a status indication as a failed component.
Contents
A machine stops at a program block. Someone opens diagnostics and interprets diagnosis 0 on the newer control using an old “000 waiting for FIN” reference. This shortcut can send the investigation toward an unrelated auxiliary-function circuit. The issue is not the leading zeros: it is whether the control generation, data type and entry name match the manual.
Scope: two specified editions, not every 0i
This comparison uses FANUC maintenance manuals B-64605EN/01 (0i-MODEL F) and B-64115EN/02 (0i/0i Mate-MODEL C). The former, §1.3.2, printed page 15, defines diagnosis 0 as bit-type CNC internal state 1. The latter, Chapter 1, printed page 62, lists separate numbers: 000 is WAITING FOR FIN SIGNAL, 003 in-position check, 004 feedrate override 0%, and 005 interlock/start lock. Do not transfer that numbering to 0i-F. Other generations, software editions and builder-customized screens need separate verification.
0i-F: read the name before the value
B-64605EN/01 §1.3.2 gives these meanings when a diagnosis 0 entry shows 1:
- INPOSITION CHECK: an in-position check is underway.
- FEEDRATE OVERRIDE 0%: feedrate override is zero.
- INTER/START LOCK ON: interlock/start lock is active.
- SPEED ARRIVAL ON: waiting for the speed-arrival signal to become active, not confirmation that speed has arrived.
The same section separately defines diagnosis 2 as dwell execution. Section 10.5, printed page 504, directs the already-started cycle branch, showing STRT, to diagnosis 0 entries displaying 1. This differs from a cycle that never started.
Turning a status into a testable interpretation
The following is our read-only analysis method, not an additional manufacturer procedure. First preserve the full diagnosis screen, CNC status, current block, path and axis identifiers from the same moment. Record the actual labels rather than substituting familiar old terminology. If the screen does not match the manual, resolve that mismatch before guessing bit meanings.
For a speed-arrival wait, the defensible interim conclusion is “the control is waiting for this condition,” not “the spindle encoder has failed.” The current program requirement, builder logic and actual feedback need correlation before distinguishing an unmet condition from a signal-chain problem or another cause. A single status image cannot make that distinction or justify replacing the spindle amplifier.
For zero feedrate override or an active interlock, relate the indication to the operator’s intent and the builder’s permitted conditions. Do not turn an override switch, change modes or force signals merely to clear an entry: removing a waiting condition can allow motion to resume. This article provides no interlock bypass method.
In-position checking is not a part-accuracy verdict
B-64605EN/01 §10.5, printed page 504, relates the in-position check to diagnosis 300 position error and parameter 1826 in-position width. The parameter number identifies the criterion; it is not an instruction to change its value.
Separate “waiting for in-position” from “the reason for the wait has been established.” An entry of 1 alone lacks the axis mapping and a corresponding error record in the same state. Without those, attributing the wait directly to mechanical binding or a drive failure is premature. Conversely, an entry becoming inactive is not acceptance evidence for part dimensions, backlash or overall machine accuracy.
An illustrative example and a useful handover
Suppose a 0i-F screenshot headed CNC internal state 1 shows SPEED ARRIVAL ON as 1, while the repair note says “diagnosis 000 = waiting for FIN.” This is an illustration, not a repair case from our workshop. Correct the version mismatch first, then gather evidence about the displayed waiting condition. Do not follow the old table directly into investigating a tool-change completion signal.
A handover can state: “Control and manual editions confirmed; entry names, values and program context preserved; waiting condition identified, component cause undetermined.” Arrange builder-approved targeted checks only after gathering relevant evidence. Motion tests, energized measurements and parameter changes belong to qualified personnel following the complete machine’s safety procedures.
Sources and verification limits
Both sources below are FANUC-authored manuals on third-party public mirrors, not official FANUC download sites. The specified editions’ definitions and diagnostic branches were checked. No specific machine was tested, and no user machine’s ladder or software configuration was verified.
- FANUC Series 0i-MODEL F Maintenance Manual B-64605EN/01 (public mirror of the FANUC-authored manual): §1.3.2, printed p. 15; §10.5, printed pp. 503–504.
- FANUC Series 0i/0i Mate-MODEL C Maintenance Manual B-64115EN/02 (public mirror of the FANUC-authored manual): Chapter 1, printed p. 62; §8.5, printed p. 471.