What causes FANUC alarm PS034?

Part program contains an illegal or incorrectly formatted command for this alarm type. Missing required address word or parameter value in the program block. Programmed value is outside the allowable range for this function. Conflict between the commanded function and the current modal state. Program post-processor not configured correctly for this Fanuc series.

How do I fix FANUC alarm PS034?

1. Note the block number from the Fanuc alarm screen and locate it in the program. 2. Review the command in that block against the Fanuc programming manual for alarm PS034. 3. Check for missing address words, incorrect values, or conflicting G-code combinations. 4. Verify any required machine options are enabled if using advanced functions. 5. Correct the program and verify before resuming machining.

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FANUC Controller

Program/G-code · Basic · 10 minutes

Alarm PS034

Fanuc Alarm PS034 - Tool Compensation Not Started

PS034 occurs when G40 (tool radius compensation cancel) is commanded in the program without a prior G41 or G42 compensation activation command. The Fanuc control detects an attempt to cancel a compensation mode that was never initiated, creating a logical programming error that prevents execution.

FANUCProgram/G-codeBasic10 minutes

PS034

Fanuc Alarm PS034 - Tool Compensation Not Started

ONLY G00/G01 ALLOWED IN STUP/EXT BLK

Root Cause Summary

PS034 occurs when G40 (tool radius compensation cancel) is commanded in the program without a prior G41 or G42 compensation activation command. The Fanuc control detects an attempt to cancel a compensation mode that was never initiated, creating a logical programming error that prevents execution.

Safety

Verify tool path before running

Causes and Fixes

1
Review the active program at the alarm stop point. Press RESET, then navigate to EDIT mode and search backwards from the current line for G40, G41, or G42 commands to verify sequence.
2
Check if program restart or block skip functions bypassed the initial G41/G42 activation. Verify parameter 3402#3 (RST) restart method and ensure compensation start blocks were not skipped.
3
If using subprograms (M98/M99), verify that G41/G42 is called in the main program before the subprogram containing G40. Compensation cannot start in one program level and cancel in another without proper sequencing.
4
Correct the program by either removing the unnecessary G40 command or adding the appropriate G41/G42 activation command with valid D-code offset before the G40 cancel line.

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