61326

Common Causes

• Incorrect _MD parameter value set in probing cycle initialization
• Parameter _MD not properly defined before cycle execution
• Wrong sign convention used for measuring direction (positive vs negative)
• Parameter corruption or incorrect value loaded from backup
• Probing cycle called with undefined or out-of-range _MD value

Troubleshooting Steps

1. 1Navigate to the affected channel and block in the program, identify the CYCLE973 or CYCLE976 call and verify the _MD parameter is explicitly defined with correct sign convention before cycle execution
2. 2Check the machine documentation for correct _MD sign convention (typically positive for approach direction, negative for retract or alternative measurement direction)
3. 3Verify _MD parameter value is within valid range and matches the probe type and measurement intent in your application
4. 4Review parameter settings in the machine data or part program to ensure _MD is initialized correctly; reload parameters from known good backup if corruption is suspected
5. 5Test with a simple standalone cycle call using verified _MD value to isolate whether issue is parameter definition or cycle logic