What causes FANUC alarm 034?

Part program contains an illegal or malformed command related to the alarm condition. Missing required address word or parameter value in the program block. Programmed value is out of the allowable range. Conflict between active modal codes and the commanded function. Post-processor configuration mismatch for this Fanuc series.

How do I fix FANUC alarm 034?

1. Note the block number shown in the alarm screen and locate that block in the program. 2. Review the command in that block against the Fanuc programming manual. 3. Check for missing words, incorrect values, or conflicting G-code combinations. 4. Verify the program is post-processed for the correct Fanuc series. 5. Correct the program and dry-run at low speed before resuming machining.

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FANUC Controller

Program/G-code · Basic · 5-10 minutes

Alarm 034

Fanuc Alarm 034 - Rewind Stop Code Found

Alarm 034 occurs when the CNC detects a rewind stop code (%) at the beginning of a program search operation, indicating the search cannot proceed because it has immediately encountered the end-of-program marker. This typically happens when attempting to search backward from the program start, searching in an empty program area, or when the program pointer is positioned at the % character during search initiation.

FANUCProgram/G-codeBasic5-10 minutes

034

Fanuc Alarm 034 - Rewind Stop Code Found

Rewind Stop

Root Cause Summary

Alarm 034 occurs when the CNC detects a rewind stop code (%) at the beginning of a program search operation, indicating the search cannot proceed because it has immediately encountered the end-of-program marker. This typically happens when attempting to search backward from the program start, searching in an empty program area, or when the program pointer is positioned at the % character during search initiation.

Safety

Search cannot continue

Causes and Fixes

1
Press RESET to clear the alarm. Check current program position on PROGRAM screen and verify cursor/execution pointer location relative to the % character.
2
If performing a restart search, ensure the search start position is set to a valid block number within the program body, not at the % rewind code. Check parameter 3107#0 (background edit enable) if applicable.
3
Navigate to SYSTEM > PARAM and verify parameter 3204 (program restart method) settings. Adjust search direction or starting sequence number to position within the program.
4
Restart the search operation from a valid program block after the % character, or manually advance program pointer to the desired restart position before initiating search.

DIY Feasiblehigh confidence

Call a technician if:

·Parameter corruption suspected
·Repeated alarms after program corrections
·Hardware encoder issues affecting position feedback

Prevention

Always use G00 or G01 before compensation commands
Structure programs to separate compensation from canned cycles
Use program verification tools to check modal states

Common Mistakes

Forgetting to cancel canned cycles before compensation
Mixing polar coordinates with cutter compensation
Not checking modal G-code states before compensation startup

Related Alarms

033 035 036 037

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