61504

Navigate to Diagnostics > Machine Data (MD) and search for grinding-related parameters containing 'KNG' or 'dressing'. Verify MD numbers 35400-35499 (grinding wheel parameters) are populated.

Do not modify MD values without documentation; note current values first.

In the NCK program, locate the setup function call in block %2. Verify that _KNG is assigned a valid numeric value (typically in mm or µm depending on MD 35410 'grinding wheel diameter') before the grinding cycle block executes.

Check the channel-specific setup data (Channel > Setup Data menu) for channel %1 and confirm _KNG variable is declared and initialized in the setup sub-program or preamble.

Open the part program in the Program Editor and examine the _KNG variable declaration. Confirm it is declared as REAL or INT (e.g., 'DECLARE REAL _KNG') and not as STRING or other incompatible type.

Verify the assignment statement uses correct syntax: '_KNG = <numeric_value>' (e.g., '_KNG = 0.05' for 0.05 mm offset). Check for stray characters, quotes, or conditional logic that may alter the value.

Verify against the machine builder's grinding cycle documentation for correct _KNG format and units.

Re-compile or load the part program (Program > Load) and execute a dry-run (Automatic > Single Block mode) to isolate the exact block %2 where the alarm fires.

Check the control firmware version: Diagnostics > System Information > Firmware Version. Cross-reference with the part program header comments to ensure the grinding cycle is compatible with the installed SINUMERIK 840D version (e.g., ≥11/2006 Edition).

Verify grinding functionality is licensed: Diagnostics > License Management and confirm the 'Grinding' option is active. If not present, contact Siemens Field Service to enable the grinding package.

Without a valid grinding license, grinding-specific setup functions will always fail.

Obtain the correct grinding cycle sub-program from the machine builder or Siemens Application Engineering and re-load it into the NCK. Ensure the setup function signature matches the current control's NCK syntax.