What causes FANUC alarm 350?

Synchronous axis parameter (8180 series) has an axis number that does not exist on this machine. Duplicate axis assignment — same axis number used for multiple synchronous pairs. Parameter set to an axis that is already assigned to another control function. Parameter file restored from a different machine configuration. Zero or invalid axis number in the synchronous control parameter.

How do I fix FANUC alarm 350?

1. Review the synchronous control axis parameters (8180-8183 or equivalent) for valid axis numbers. 2. Verify each axis number referenced exists on this machine and is not duplicated. 3. Power cycle after correcting the parameters to reinitialize the synchronous control configuration. 4. Compare against the backup parameters or machine builder specification.

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FANUC Controller

Program/G-code · Advanced · 30-90 minutes

Alarm 350

Fanuc Alarm 350 - PARAMETER OF INDEX OF SYNCHRONOUS CONTROL AXIS SET ERROR

Alarm 350 SYNCHRONOUS CONTROL AXIS SET ERROR occurs when parameter 8180 contains an invalid axis number for synchronous control operation. This typically happens after parameter changes, axis reconfiguration, or when attempting to synchronize axes that don't exist or aren't properly configured in the system.

FANUCProgram/G-codeAdvanced30-90 minutes

350

Fanuc Alarm 350 - PARAMETER OF INDEX OF SYNCHRONOUS CONTROL AXIS SET ERROR

PARAMETER OF INDEX OF SYNCHRONOUS CONTROL AXIS SET ERROR

Root Cause Summary

Alarm 350 SYNCHRONOUS CONTROL AXIS SET ERROR occurs when parameter 8180 contains an invalid axis number for synchronous control operation. This typically happens after parameter changes, axis reconfiguration, or when attempting to synchronize axes that don't exist or aren't properly configured in the system.

Safety

Home position may be incorrect

Causes and Fixes

1
Navigate to SYSTEM > PARAM and check parameter 8180. Verify the axis number set matches an actual controlled axis in your system (typically 1-8 for standard configurations).
2
Check parameter 1020 (number of controlled axes) to confirm total axes available. Parameter 8180 value must not exceed this number and must reference a valid axis.
3
Verify parameter 8181 (master axis for synchronous control) is also set correctly and references a different valid axis than parameter 8180.
4
Correct parameter 8180 to a valid axis number (typically Z-axis is axis 3, but verify against your machine configuration). Power cycle the control after parameter write to clear the alarm.
Parameter write enable (bit 0 of parameter 3202) must be set to 1. Record original values before making changes.

DIY Feasiblehigh confidence

Call a technician if:

·Encoder replacement required
·Servo amplifier replacement needed
·Multiple axes showing same alarm

Prevention

Regular encoder cable inspection during PM
Maintain proper cable strain relief
Keep encoder connections clean and dry
Monitor encoder diagnostic parameters monthly

Common Mistakes

Assuming cable is good without continuity test
Ignoring encoder LED status indicators
Incorrect parameter restoration after amplifier replacement
Not performing encoder calibration after replacement

Related Alarms

351 352 353 410 411

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