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Check safety input status

Navigate to HMI > Diagnostics > Safety > Safety Inputs and verify status of all configured safety inputs in MD36300 (SAFE_INPUT_ASSIGN).

Use SINUMERIK Operate safety diagnostics screen to see real-time safety input states

Inspect physical safety devices

Verify all safety gates are properly closed, light curtains are unobstructed, and emergency stop buttons are not activated.

Do not bypass safety devices - resolve the actual safety condition first

Reset safety system

After clearing safety condition, perform safety acknowledgment via HMI safety reset button or execute safety reset sequence defined in MD36350 (SAFE_RESET_MODE).

Some systems require two-hand reset or key switch activation for safety reset

Check SINAMICS safety status

Access STARTER or TIA Portal, navigate to drive safety diagnostics and check safety function status, particularly SS2 monitoring parameters P9601-P9610.

Use r9773 (safety status word) to identify specific safety function that triggered

Verify safety parameter consistency

Check safety parameters P9501 (SS2 monitoring time) and P9502 (SS2 speed threshold) for proper configuration and ensure safety acceptance test is valid.

Safety parameter changes require new safety acceptance test and validation

Perform safety reset sequence

Execute safety reset via P9699=1 or through configured safety reset input, then restart drive operation after confirming safety condition clearance.

Monitor r9774 (safety diagnostic word) during reset to verify proper sequence completion

Check safety PLC status

Access safety program via STEP 7 Safety or integrated safety editor, monitor safety program execution and check safety data blocks for active SS2 commands.

Use safety program online monitoring to trace which safety function block triggered SS2

Analyze safety logic conditions

Review safety program logic for conditions that trigger SS2, check safety zone monitoring, speed limits, and interlocking conditions in safety FB blocks.

Only qualified safety engineers should modify safety PLC programs

Reset safety program state

Clear safety program conditions causing SS2 activation, then execute safety reset sequence through HMI or safety program reset function.

Document safety events in safety log for compliance and troubleshooting history

Check PROFIsafe communication

Navigate to HMI > Diagnostics > PROFIsafe and verify all safety devices show 'RUN' status, check F_Dest_Add and F_Source_Add parameters for communication integrity.

Monitor PROFIsafe timeout counters and CRC error statistics for intermittent issues

Verify safety network topology

Check PROFINET/PROFIBUS safety network connections, verify proper termination and cable integrity for safety-relevant communication paths.

Use only approved safety-rated cables and connectors for PROFIsafe networks

Restart safety communication

Perform controlled restart of PROFIsafe communication via network diagnostics, re-establish safety connections and verify proper handshaking.

Allow sufficient time for PROFIsafe startup sequence - typically 30-60 seconds for full initialization