What causes FANUC alarm 162?

Part program contains an illegal G-code or M-code combination for this alarm type. Missing or incorrect address word in the program block. Axis or parameter value out of range for the commanded function. Required option not enabled on this CNC for the commanded function. Conflict between active modal states and the commanded function.

How do I fix FANUC alarm 162?

1. Note the block number shown on the alarm screen and locate that block in the program. 2. Review the command in that block against the Fanuc programming manual for alarm 162. 3. Check for missing address words, incorrect values, or conflicting G-code combinations. 4. Verify any required CNC options are enabled if using advanced functions. 5. Correct the program and verify the fix before restarting machining.

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FANUC Controller

Spindle · Intermediate · 5-30 minutes

Alarm 162

Fanuc 162 - Illegal spindle speed command

Alarm 162 occurs when the CNC control receives a spindle speed command (S-code) that is outside the allowable range, improperly formatted, or conflicts with machine parameters. This is typically caused by programming errors such as exceeding maximum spindle RPM limits, using decimal values where integers are required, or issuing spindle commands when spindle parameters are incorrectly configured.

FANUCSpindleIntermediate5-30 minutes

162

Fanuc 162 - Illegal spindle speed command

ILLEGAL SPINDLE SPEED COMMAND

Root Cause Summary

Alarm 162 occurs when the CNC control receives a spindle speed command (S-code) that is outside the allowable range, improperly formatted, or conflicts with machine parameters. This is typically caused by programming errors such as exceeding maximum spindle RPM limits, using decimal values where integers are required, or issuing spindle commands when spindle parameters are incorrectly configured.

Safety

Verify corrected program or parameters before resuming machining

Causes and Fixes

1
Identify the S-code value in the program line where the alarm occurred (check program display or alarm history for line number).
2
Access parameters 3741 (max spindle speed for 1st gear), 3742 (2nd gear), 3743 (3rd gear), and 3744 (4th gear) to verify maximum allowable spindle speeds for each gear range.
Record original parameter values before making any changes. Incorrect parameter modification can damage the spindle.
3
Compare the commanded S-code value against the appropriate gear range maximum. If exceeded, reduce the S-code value in the program to within acceptable limits.
4
If the speed is legitimate for your spindle, verify parameter 3741-3744 settings with machine documentation and adjust if incorrectly set (requires proper authorization and OEM documentation).
Consult machine manufacturer specifications before increasing maximum spindle speed parameters to prevent spindle damage.

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