27203

Navigate to Siemens HMI > Diagnosis > Machine Data > Safety (MD 20000-20999 range) and locate the failing MD referenced in alarm message parameter %1[%2].

Record the exact MD number and current bit limit values before modification.

Verify bit assignment syntax: confirm that the lower bit value (left operand) is numerically less than or equal to the upper bit value (right operand) in the SPL interface definition.

SINUMERIK interprets bit ranges as [lower:upper]; reversed values cause immediate parameter validation failure.

Correct the bit limit values to proper ascending order, then activate the changes via PLC > Upload to NCK or equivalent synchronization method.

Perform an NCK reset (warm restart) to reload safety parameter definitions and re-validate SPL-to-module mapping.

Access the HMI machine data editor and identify the failing MD SPL parameter (%1[%2] from alarm). Document the bit position values currently assigned.

Check the alarm message details panel for the specific bit value that exceeds limits.

Cross-reference the PROFIsafe module hardware configuration (typically in STEP7-Safety or TIA Portal) to confirm maximum SPL bit width supported (standard is 0-63 for 64-bit interface, or separate multi-word SPL if configured).

Ensure the module definition matches the NCK SPL interface capacity declared in MD.

Reassign the signal to a valid bit range (0-63) within the current SPL interface, or if required, reconfigure to use a secondary SPL interface word (MD20100+n) with appropriate module slot mapping.

Validate the updated SPL mapping by uploading the corrected machine data to the NCK and performing a complete safety I/O check via Diagnostics > Safety > PROFIsafe Module Status.

Retrieve the PROFIsafe module configuration from the project engineering tool (STEP7-Safety or TIA Portal) and extract the signal list with assigned bit positions for the module referenced in the alarm.

Ensure you have the current module firmware version configuration; version mismatches can cause signal definition changes.

Compare the engineering configuration bit assignments against the NCK machine data SPL parameters (MD 20100+ series). Verify that each signal bit range in MD matches the module's published SPL signal map exactly.

Off-by-one errors or overlapping bit ranges are common causes; check for bit range overlap across multiple signals.

Correct the machine data SPL assignments to precisely match the module signal definition, then re-upload the configuration to the NCK control.

Clear the alarm via reset, then monitor the PROFIsafe module status in Diagnostics to confirm successful signal handshake and module readiness.