231-A950

Check current SLI increment setting

Access MOD function and navigate to Settings → Machine → SLI Settings to verify the current increment value being used.

The increment value is displayed in the SLI dialog box when activated

Verify distLimitJog parameter

In machine parameter menu, check MP7680.x distLimitJog for the affected axis to confirm the maximum allowed increment distance.

Only qualified personnel should modify safety-related machine parameters

Adjust increment value

Reduce the SLI increment to a value below the distLimitJog limit, typically 50-80% of the maximum allowed value for safety margin.

Use smaller increments near workpiece or fixture boundaries

Monitor position following error

Access Diagnostics → Axis Status and observe the following error (Schleppfehler) during SLI movements to identify overshoot behavior.

Following errors >0.1mm during SLI indicate tuning issues

Check velocity and acceleration limits

Verify MP1010 (maximum velocity) and MP1020 (maximum acceleration) are appropriate for the mechanical system and load conditions.

Excessive acceleration can cause mechanical overshoot

Review servo loop parameters

Check position loop gain (MP1410 Kv factor) and velocity loop parameters for optimal tuning without overshoot.

Reduce Kv factor by 10-20% if consistent overshoot occurs

Test with reduced feed rate

Temporarily reduce SLI feed rate using F-key override to verify if overshoot is velocity-dependent.

Perform backlash measurement

Use TNC backlash compensation test in Setup → Axis Test to measure actual backlash and compare with MP1050 backlash compensation values.

Backlash >0.05mm typically indicates mechanical wear

Check mechanical components

Inspect ball screw, linear guides, and couplings for wear, proper lubrication, and correct preload adjustment.

Ensure machine is properly locked out before mechanical inspection

Update backlash compensation

Adjust MP1050 backlash compensation value based on measured results and re-test SLI operation.

Set compensation to 110% of measured backlash for safety margin

Verify encoder signals

Check Diagnostics → EnDat/SSI Status for encoder communication errors, signal quality, and proper EnDat protocol operation.

Signal amplitude should be >1.0Vpp for reliable operation

Inspect encoder connections

Verify encoder cable connections at motor, drive, and TNC are secure and show no signs of damage or contamination.

Power down system before checking encoder connections

Validate encoder scaling

Confirm MP910 (linear encoder) or MP920 (rotary encoder) scaling parameters match the actual encoder specifications.

Use precision measurement tools to verify actual vs. displayed position