61807

Review the CYCLE840 call in the NC program block identified in alarm parameter %2. Check the direction parameter (typically 3rd or 4th parameter) of the cycle invocation.

Verify the M-code spindle commands (M3/M4/M5) immediately before or within the CYCLE840 block. Compare against the cycle's required direction: if CYCLE840 expects CCW (direction = -1 or equivalent) but M3 (CW) is active, the conflict occurs.

Check program sequence—M-codes executed in the same or preceding block may still be active when cycle executes.

Modify the NC program to remove conflicting M-codes or adjust the CYCLE840 direction parameter to match the spindle direction already commanded. Ensure spindle direction is either undefined (M5 active) or matches the cycle requirement before CYCLE840 execution.

In Siemens HMI (or via SINUMERIK Operate), navigate to Diagnostics > Machine Data > Spindle Parameters. Verify MD10210 (spindle type designation) and MD10216 (spindle direction control enable) are correctly configured for the spindle referenced by CYCLE840.

Check the active spindle number in the program (S-value spindle selection if multi-spindle system). Confirm CYCLE840 is targeting the correct spindle via its spindle parameter, and that spindle's direction capability matches the cycle's direction requirement.

Multi-spindle systems: verify spindle selection (ASPINDLE or equivalent) is synchronized with CYCLE840 spindle parameter.

Monitor the actual spindle direction state via NCK variable read (if accessible via OPI) or PLC diagnostic display. Ensure the spindle is in the expected state (CW/CCW/stop) before CYCLE840 execution, correcting any residual direction state from prior operations.

Review the CYCLE840 call syntax in the identified NC block. Verify that the direction parameter is explicitly defined (e.g., CYCLE840(..., 1, -1) for CW/CCW or equivalent) and not passed as an undefined or zero-valued variable.

Check Siemens SINUMERIK 840D documentation for CYCLE840 parameter definitions; confirm the direction parameter range (typically -1, 0, or 1 for CCW, stop, CW). Ensure the value used in the program matches documented conventions.

If direction is variable-dependent, add explicit initialization and range-check logic in the NC program prior to CYCLE840 invocation. Recompile and test to confirm the cycle accepts the spindle direction state.