21703

Verify physical probe contact by manually triggering the probe stylus perpendicular to its axis and listening/feeling for the click. Check for bent, worn, or obstructed stylus preventing deflection.

Do not apply excessive force - probe stylus typically requires 500-800g deflection force.

Inspect probe connector and cable for corrosion or loose pins. Check cable continuity with multimeter between probe connector and machine spindle/tool holder interface per your machine's probe connection documentation.

Machine must be powered down and in manual mode before testing electrical continuity.

In MDI mode, execute G65 manual probe test cycle or use Diagnostics > Probing > Manual Test (path varies by control version) to observe probe signal state changes in real-time before launching measurement program.

Replace probe stylus or entire probe assembly if deflection test fails. Verify replacement probe part number matches original specification in machine documentation.

Navigate to Diagnostics > Parameters > Machine Data > MD 32300 (ProbeSignalMode). Verify value matches your probe type: typically 1=TTL active high, 2=TTL active low, or 3=analog. Cross-reference with probe documentation and control manual Section 4.3.2.

Check MD 32301 'ProbeSignalType' and MD 32302 'ProbeSignalEdge' values. Confirm edge setting (rising vs. falling) matches probe mechanical behavior. Test by deflecting probe manually while monitoring signal in Diagnostics > IO-Field > Probe Signal (or equivalent menu).

If signal polarity appears inverted, toggle MD 32302 value and save with MD 32010 (ActivateMachineData=1). Perform probe contact test again in Diagnostics > Probing menu.

Machine parameters require control restart. Verify no other CNC programs are queued before saving.

If issue persists, compare current MD 32300-32310 parameter block with control backup or OEM default configuration. Re-flash probe configuration via control System > Hardware > Probe Setup if available.

Review the NC program MEAWA/MEASA/MEAC block syntax: verify the first edge parameter (e.g., bit 0 of measurement parameter word specifies rising/falling). Reference control documentation 'Probing Cycles' section for correct syntax and parameter bit definitions.

Insert a manual probe deflection in MDI before the measurement block to establish known initial state. Monitor probe signal in real-time using Diagnostics > IO-Field > Probe Input to confirm expected signal level before MEAWA/MEASA execution.

Modify the measurement block edge specification to match the opposite transition (if original was rising edge, change to falling, or vice versa). Re-run program and observe if alarm clears, indicating inverted logic assumption.

If program logic is correct but workpiece setup has changed (probe now approaches from different axis, different workpiece height, etc.), recalibrate probe reference position using control built-in probe calibration cycle per your machine model documentation.