SRVO-011

Visually inspect all E-stop devices

Check all emergency stop buttons on the teach pendant, operator panel, and any external E-stop stations. Verify none are pressed or mechanically stuck. On R-30iB controllers, a pressed E-stop will show a red indicator on the button itself and the controller front panel EMERGENCY STOP LED will be illuminated.

Do not defeat or bypass E-stop circuits. These are safety-critical devices required by ANSI/RIA R15.06 standards.

Check safety chain continuity

Navigate to MENU → SYSTEM → Safety → Safety I/O to view safety circuit status. Check *CSTOPI (chain E-stop input) and safety relay states. Verify all safety devices (enabling device, deadman switch, mode selector) are in proper operating state. All safety inputs should show 'ON' when the circuit is complete.

On R-30iB Plus controllers with DCS (Dual Check Safety), both Channel A and Channel B must be closed. Check MENU → SYSTEM → DCS Monitor to verify both channels show identical safe states.

Review alarm history for E-stop source

Press MENU → ALARM → ALARM LOG (F1). Look for the alarm immediately preceding SRVO-011. Common alarms include SRVO-001 (operator panel E-stop), SRVO-002 (external E-stop), or SAFE-xxx series alarms. The timestamp will indicate which E-stop device triggered first.

Use F5 [DETAIL] on the alarm log entry to see exact I/O states and robot position at the moment of the fault. This data is crucial for recurring nuisance trips.

Reset E-stop and restore servo power

Release all E-stop buttons by rotating clockwise until they pop out. Verify teach pendant deadman switch is released. Press the RESET button on the teach pendant. The FAULT LED should extinguish. Press and hold the deadman switch in the middle detent position, then press SHIFT + RESET to restore servo power to all groups.

Ensure all personnel are clear of the robot work envelope before restoring servo power. Verify robot will not move unexpectedly upon power restoration.

Inspect all perimeter guards and gates

Walk the entire robot cell perimeter and verify all access gates are fully closed and latched. Check gate-mounted safety switches (typically Sick, Schmersal, or Pilz devices) for proper mechanical engagement. Look for misaligned strike plates, worn latches, or debris preventing full closure.

Many interlock switches have diagnostic LEDs. A properly closed and functioning switch shows a solid green or yellow LED depending on manufacturer. Flashing or red LEDs indicate a fault condition.

Check light curtain and area scanner status

If the cell uses safety light curtains or laser scanners, check the device status indicators. Navigate to MENU → I/O → Digital → Inputs and monitor the safety input signals (typically SI[1] through SI[16] on DCS systems). Identify which input has changed state. Cross-reference with cell wiring diagrams to identify the physical device.

Never bypass or jumper safety light curtains. These devices provide presence-sensing safeguarding and are legally required in many jurisdictions.

Verify safety interlock wiring integrity

Check for damaged cables between safety devices and the controller. On R-30iB with DCS, verify continuity of both dual-channel safety wiring. Use MENU → SYSTEM → DCS Monitor → Safety I/O Detail to compare Channel A and Channel B inputs. Any discrepancy indicates a wiring fault, broken conductor, or failed safety device.

Intermittent interlock faults are often caused by loose terminal connections in the interlock chain. Check tightness of all terminals in junction boxes and on the FSU connector panels using proper torque specifications (typically 0.5-0.6 N⋅m for FSU terminals).

Test interlock reset functionality

After securing all guards, verify the safety circuit reset mechanism functions properly. Some systems require a deliberate reset action (reset button press) after closing interlocks. Check for illuminated reset buttons at operator stations. Monitor MENU → SYSTEM → Safety → Safety I/O while performing the reset to confirm all inputs transition to safe state.

If the system uses safety relay modules (Pilz PNOZ, Sick UE410, etc.), these often require a power cycle or dedicated reset input after a fault. Check the safety relay module status LEDs and consult the specific relay documentation for reset procedures.

Review complete alarm chronology

Press MENU → ALARM → ALARM LOG and carefully examine all alarms in time sequence. Note the very first alarm before SRVO-011 appeared. Common triggering alarms include SRVO-037 (excess position error), SRVO-050 (amplifier overload), SRVO-038 (motor overheat), MOTN-023 (position error too large), or SAFE-series alarms. The earliest alarm is usually the root cause.

Use F4 [TIME] to sort alarms chronologically. The root cause alarm may have occurred milliseconds before SRVO-011. Pay attention to alarms on specific axes or groups, as these indicate the problem originated in that particular servo channel.