231-A890

Access Machine Parameters

Press MOD key, select 'Machine Parameters', navigate to CfgAxParSafety section for the affected axis.

Always backup current parameters before making changes using the parameter export function.

Verify absLimitNeg Setting

Check the absLimitNeg value against machine drawings and actual travel limits. Compare with positive limit absLimitPos for consistency.

Incorrect limits can cause crashes - verify with machine documentation.

Adjust Parameter Value

Modify absLimitNeg to appropriate negative value based on machine specifications. Ensure adequate safety margin from hard stops.

Set software limits 2-5mm inside hardware limit switch positions for safety buffer.

Perform Parameter Reset

Execute parameter reset cycle and test axis movement in both directions at reduced feedrate to verify new limits.

Check Reference Point Status

Verify REF indicator on position display. If missing, the axis has lost reference and needs re-homing.

Never assume reference is correct after power loss or emergency stop.

Execute Reference Point Return

Select Manual mode, press REF key, and run reference point sequence for affected axis. Monitor encoder feedback during homing.

Always reference all axes in proper sequence - typically Z first, then X and Y.

Verify Datum Settings

Check active datum shifts in position display and verify G54-G59 coordinate systems are within expected ranges.

Use PRESET table to verify work coordinate systems haven't been corrupted.

Test Movement Range

Manually jog axis through full travel range at 10% rapid to confirm software limits are respected.

Review Active Program Block

Check current program line in NC display for excessive negative coordinates. Look for missing decimal points or sign errors.

Use program graphics simulation to visualize tool path before execution.

Verify Work Coordinate System

Check active G54-G59 offset values in PRESET table. Ensure work zero hasn't shifted outside machine envelope.

Incorrect work offsets are a leading cause of crashes and limit violations.

Analyze Program Logic

Review program for G91 incremental moves, tool length compensation (G43), and cutter radius compensation (G41/G42) that may extend beyond limits.

Pay special attention to rapid positioning moves (G00) which often trigger limit violations first.

Modify Program or Setup

Correct programming errors or adjust work coordinate system to keep all movements within software limits.

Monitor Position Display

Watch position readout during manual jogging for erratic jumps, missing counts, or inconsistent feedback values.

Encoder problems can cause unpredictable machine behavior - proceed with extreme caution.

Check Encoder Connections

Inspect encoder cable connections at motor and drive for looseness, contamination, or damage. Verify shield continuity.

Encoder cables are sensitive to EMI - route away from power cables and check for proper shielding.

Verify Drive Status

Check servo drive LED indicators and diagnostic displays for fault codes or warning conditions affecting position feedback.

Document any intermittent drive faults as they often precede major failures.

Test Encoder Function

Use TNC diagnostic functions to monitor encoder signals and verify proper quadrature operation and reference mark detection.