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FANUC Controller
Program/G-code · Intermediate · 5-30 minutes
Fanuc 242 - Speed control data error
Alarm 242 indicates an error in spindle speed or feed rate command formatting within the part program. This typically occurs when S (spindle speed) or F (feed rate) values are outside allowable ranges, improperly formatted, or incompatible with the current machine mode or gear range.
242
Fanuc 242 - Speed control data error
SPEED CONTROL DATA ERROR
Fanuc PS program alarm 242: SPEED CONTROL DATA ERROR. This alarm is triggered by an illegal or incorrectly formatted command in the part program, or a programming condition that the Fanuc control cannot execute.
Root Cause Summary
Alarm 242 indicates an error in spindle speed or feed rate command formatting within the part program. This typically occurs when S (spindle speed) or F (feed rate) values are outside allowable ranges, improperly formatted, or incompatible with the current machine mode or gear range.
Safety
- Verify corrected program or parameters before resuming machining
Causes and Fixes
- 1
Identify the block number from the alarm display and locate the S command in the part program.
- 2
Check parameters 3741-3744 (max spindle speed for each gear) and parameter 3731 (minimum spindle speed) to verify allowable ranges.
- 3
Verify the programmed S value is within the physical spindle speed limits and appropriate for the current gear range or constant surface speed mode.
- 4
Correct the S value in the program to fall within allowable limits or modify M41-M44 gear selection if applicable.
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