16774

Check machine control panel and HMI logs for RESET button activation or emergency stop (E-STOP) events during the timestamp when alarm 16774 occurred.

Verify NC program logic around EGONSYN/EGONSYNE blocks; confirm intentional RESET is not called within the synchronization G-code sequence via M0/M1 or explicit RESET macro calls.

Review PLC safety logic and interlock conditions (check OB1/OB10 and relevant safety FB blocks) to ensure no unintended RESET is being triggered by fault conditions or sensor logic during synchronization.

Repeated RESET during sync indicates potential upstream fault masking the root cause.

If RESET is intentional, restructure NC program to complete synchronization before RESET, or use conditional EGONSYN logic with error handling (ONERROR blocks) to gracefully exit sync mode.

Review NC program structure and locate all M02/M30 statements; verify none occur within or immediately after EGONSYN/EGONSYNE blocks without proper sync completion (typically requiring axis position confirmation via AXSTAT or coupling-state check).

Inspect conditional logic (IF/ELSE, GOTO, WHILE loops) around synchronization code; ensure EGONSYN/EGONSYNE blocks execute atomically and are not skipped by program jumps or loop termination.

Check MD 35100 (CfgSpindleAxisCoupling) and MD 35101 (CfgSpindleAxis) to confirm slave axis is properly registered for synchronization.

Add synchronization completion verification logic: insert AXSTAT or GETSYNCMODE checks after EGONSYN/EGONSYNE to confirm coupling state before program termination; use M17 (subprogram end) instead of M30 if in subprogram context.

If M02/M30 must occur during sync, implement a state machine using SYSF flags (e.g., SYSF[0]) to track sync completion and defer program termination until EGONSYN/EGONSYNE fully resolves.

Query NCK diagnostics (Siemens SINUMERIK HMI > Diagnostics > Alarms or SINUMERIK Operate interface) and cross-reference timestamps; check if any slave axis alarms (280xx, 281xx series for spindle/axis faults) appear immediately before or concurrent with alarm 16774.

Inspect slave axis encoder/feedback signals and drive status: verify encoder cable continuity, optical interface cleanliness, and drive error LEDs (check SINAMICS G120/S120 parameter p0020 Actual frequency and p0081 Mains voltage status); rectify any hardware faults (replace encoder, reseat connectors).

Do NOT proceed with synchronization testing until slave axis drive shows green status and no fault codes are present.

Review PLC program logic (OB1 cycle) and verify no conditional statements set MD 36010 (FollowUpMode) or call MOVE/MOVEFP functions on the slave axis during the EGONSYN/EGONSYNE window; confirm PLC does not interfere with axis coupling state.