SRVO-013

Check Alarm History for Program Line

Press MENU > ALARM > F2 (HISTORY). Review the timestamp and note the alarm immediately preceding SRVO-013. Check if PROG-XXX alarms or position data shows which program and line number was executing when servo-off occurred.

The alarm history shows up to 4 previous alarms before SRVO-013. The root cause alarm will typically be 1-2 positions earlier in the history list.

Review Active Program at Fault Line

Navigate to MENU > SELECT > find the program that was running. Use FIND > F5 (LINE) and enter the line number from alarm history. Examine the instruction and any conditional logic (IF/THEN statements) that may have triggered ABORT or PAUSE instructions.

Search for keywords using FIND > F3 (STRING): search for 'ABORT', 'PAUSE', 'PEND', and 'STOP' to locate all potential servo-off commands in the program.

Check Background Logic Programs

Press MENU > SETUP > Frame/Prog > MORE > F1 [TYPE] > Background Logic. Review any BG logic programs (CSTOPI, ERRORPRG, MACRO) that may have executed ABORT commands based on I/O conditions or error handlers.

Background logic programs run continuously and can trigger ABORT commands based on sensor inputs or safety conditions. Check DI/DO signals referenced in these programs using MENU > I/O > Digital.

Verify Error Handling Macros

Check System Variables $ERROR_PROG and $MOR_GRP.$ERROR_PROG (MENU > DATA > SYS Variables). If error handling is enabled, review the macro program registered here for ABORT instructions that execute on fault conditions.

Disable error handling temporarily ($ERROR_PROG = 0) to determine if the ABORT is coming from the main program or an error handler.

Identify Active Karel Programs

Press MENU > STATUS > Program Status. Note all Karel tasks shown as 'RUN' or 'PAUSED'. Cross-reference with MENU > ALARM > HISTORY timestamp to identify which Karel program was active during SRVO-013.

Karel programs appear with .PC extension in program status. Check both foreground and background task lists.

Review Karel Source for Motion Control Calls

Access the Karel program source (if available) or contact the integrator. Search for these routines: STOP_MOTION, DISABLE_SERVO, ABORT_TASK, CANCEL_MOTION, and CLEAR_MOTION_QUEUE. Check conditional logic that may trigger these calls.

Do not modify Karel programs without source code and proper recompilation tools. Incorrectly modified .PC files can cause controller instability.

Check Karel Error Logging

Review system log files via MENU > ALARM > F4 (LOG). Karel runtime errors (array bounds, null pointer, divide by zero) can trigger emergency stops. Look for KARL-XXX alarms preceding SRVO-013.

Enable enhanced Karel logging by setting $SCR.$KLIOLOG = 1, then reproduce the fault to capture detailed Karel execution traces.

Test with Karel Programs Disabled

Temporarily disable Karel autostart: MENU > SETUP > Host Comm > Karel Env. Set auto-run programs to FALSE or rename .PC files in MD: device. Run base TP program to isolate if Karel is the trigger source.

Document original Karel startup configuration before making changes. Use MENU > FILE > Set Device > MD: and press F4 (UTIL) > F5 (RENAME) to temporarily disable .PC files.

Review DCS and Safety System Alarms

Press MENU > ALARM > HISTORY and look for SRVO-XXX, SAFE-XXX, or DCSV-XXX alarms immediately before SRVO-013. Note specific alarm codes as these indicate which safety monitoring function triggered the shutdown.

Safety system alarms require root cause resolution before reset. Do not repeatedly reset without identifying the safety violation source.

Check Safety Configuration Parameters

Navigate to MENU > SYSTEM > Safety > Safety Config (password required). Review enabled safety functions: speed monitoring ($SSI.$SAFE_SPD), zone monitoring ($SSI.$SAFE_ZONE), and operational mode settings. Verify configured limits match application requirements.

Parameter $SSI.$SAFE_MON[1-8] shows active safety monitoring status. Value of 2 = active/triggered. Check these during normal operation vs. when alarm occurs.

Verify Safety I/O Signal States

Go to MENU > I/O > Safety I/O. Check safety input states (enabling device, mode selector, guard door signals). Intermittent signals or wiring issues can cause false safety triggers. Monitor signals in real-time during operation.

Use MENU > I/O > Diagnose to force safety outputs (only in T1 mode with safeties bypassed per ISO standards) to test wiring integrity. Check response time - delays over 50ms indicate wiring issues.

Test Motion in Reduced Safety Mode

Switch to T1 mode (reduced speed, enabling device required). Run the program step-by-step using SHIFT+FWD. If SRVO-013 does not occur in T1 but occurs in AUTO, this confirms speed or zone monitoring triggered the shutdown.

Check $SSI.$SAFE_AUT_SPD parameter - this sets maximum speed in AUTO mode. If robot paths approach this limit during acceleration, safety monitoring may preemptively shut down servos.