21702

Verify probe hardware connection and signal integrity. Check machine parameter MD 32100 (ProbeInputEnable) is set to 1 for active probe, and validate probe M-function assignment in MD 32150-32155 (ProbeFunction_M1 through M6) matches NC program M-code.

Ensure probe cable is not damaged and connector contacts are clean; intermittent signal loss is common cause.

In Siemens HMI > Diagnosis > Parameters > Measurement, verify probe status shows 'Ready' and signal count increments during manual probe test. Check NCK parameter MD 32000 (MeasurementParamEnable) is set to 1.

Review NC program measurement block syntax: confirm MEAWA/MEASA/MEAC block includes valid DIST= parameter (measurement distance in mm) and axis name. Verify measurement end position is physically reachable without soft limit collision.

Syntax error in MEAW block will cause silent measurement abort without probe trigger.

Activate machine diagnostic mode (Siemens HMI > Service > Diagnostics > Measurement) and execute single measurement block with G65 probe cycle to isolate hardware vs. program issue.

In Siemens HMI > Offsets > DRF (Dynamic Rest Frame), verify all axes show non-zero or explicitly-set DRF values. Check machine parameters MD 20100-20109 (DRF enable and offset values) are correctly initialized in machine startup.

Uninitialized DRF values default to 0.0, which blocks coordinate system transformation.

Navigate to HMI > Work > Workpiece > Origin and confirm ORIGIN values are set for all measurement axes (typically G54-G59 offset tables). Verify SD 42410-42419 (SetupWorkpieceOrigin_X/Y/Z) match program expectations.

Execute machine reference run (homing cycle) to reset all offset registers, then re-establish DRF and workpiece origin values before re-running measurement block.

Verify probe offset parameters MD 32140-32145 (ProbeOffsetLength for each axis) are physically accurate to actual probe tip length. Measure physical probe assembly with calipers and compare to configured MD values.

Typical probe offset error is ±5-10mm; even small errors prevent contact on precision parts.

In NC program, check MEAW/MEASA block DIST= parameter (measurement approach distance) is set 5-10mm greater than probe offset plus workpiece surface clearance to ensure contact occurs before axis limit.

Execute manual probe approach test (Siemens HMI > Service > Probe Test) at 50% feedrate to visually confirm probe tip contacts workpiece surface before axis motion stops.

Always move manually at reduced speed first to avoid probe collision damage.