Troubleshooting Error F-107: Protective Field Intrusion on NexBot Vision 332-011 Laser Safety Scanner

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Tools Required

• Appropriate PPE (Safety glasses, gloves)
• Lint-free microfiber cloth
• Isopropyl alcohol or approved lens cleaner
• Multimeter
• Laptop with NexBot Vision Configuration Software
• M12 connector tool

Article

The NexBot Vision 332-011 Laser Safety Scanner is a critical component for safeguarding robotic workcells. An F-107 error code indicates that the scanner's defined protective field has been breached, and the condition has not cleared. This triggers a stop command to the robot's safety controller, halting operations until the issue is resolved. This article outlines the common causes of this fault and provides a systematic approach to identify and correct the problem.

Symptom

When an F-107 fault occurs, you will typically observe one or more of the following:

• The connected robot system comes to a safe stop (e.g., SS1, STO).
• An error message 'F-107: Protective Field Intrusion' is displayed on the robot controller's teach pendant or the main system HMI.
• The status indicator LED on the NXB-GEN-332-011 scanner is solid red.
• The OSSD (Output Signal Switching Device) outputs from the scanner are in an OFF state, opening the safety circuit.
• The system cannot be reset or restarted; the fault immediately reappears after an attempted reset.

Cause

The F-107 fault is triggered when the scanner detects an object within its configured protective field. The most common causes include:

1. Physical Obstruction: A person, forklift, pallet, fallen part, or accumulated debris is physically present within the defined safety zone.
2. Optical Contamination: The scanner's optical window is obscured by dust, dirt, oil, coolant, weld spatter, or smudges, causing the laser to reflect improperly and register a false obstruction.
3. Environmental Interference: High concentrations of airborne particulates like dust, smoke, or steam can interfere with the laser beam. Highly reflective surfaces (e.g., polished floors, reflective tape) near the edge of a field can also cause nuisance trips.
4. Scanner Misalignment: The scanner's mounting bracket has been bumped, bent, or has loosened over time, causing the scanner to monitor an incorrect area which may include a permanent fixture.
5. Incorrect Field Configuration: The protective field is incorrectly drawn in the configuration software, causing it to overlap with a permanent part of the machine or workcell.
6. Wiring or Power Issue: A damaged cable or intermittent connection for the 24VDC power supply can cause the scanner to fault or behave erratically.

Resolution Steps

Follow these steps in order to diagnose and resolve the F-107 error. Always adhere to your facility's Lockout/Tagout (LOTO) procedures before entering a robotic workcell.

Step 1: Perform Initial Safety Precautions Before approaching the scanner or entering the hazardous area, ensure the robotic system is in a safe state. Follow all local safety protocols, including proper LOTO procedures, to de-energize hazardous equipment.

Step 2: Visually Inspect the Protective Field Carefully inspect the entire area covered by the scanner's protective field. Look for any objects that should not be there, such as tools, parts, boxes, or debris. Remove any obstructions found.

Step 3: Clean the Scanner's Optical Window Contamination on the lens is a primary cause of this fault.

1. Power down the scanner or place the system in a safe state.
2. Gently wipe the dark optical window with a clean, dry, lint-free microfiber cloth to remove loose dust.
3. If grime or oily residue remains, lightly dampen a new cloth with isopropyl alcohol (IPA) or an approved, non-abrasive lens cleaning solution.
4. Wipe the window in a single, smooth motion. Do not apply excessive pressure.
5. Allow the window to air dry completely or use a dry section of the cloth to gently dry it.
6. Inspect the window for scratches or damage that could impair operation. If significant damage is found, the unit may require replacement.

Step 4: Verify Scanner Alignment and Mounting Check the NXB-GEN-332-011 scanner's physical mounting.

1. Confirm that the mounting bracket is secure and has not been bent or damaged.
2. Check that all mounting bolts are tightened to the specified torque.
3. Verify that the scanner has not been twisted or knocked out of its original alignment. Compare its position to installation photos or drawings if available.

Step 5: Check Power and Network Connections Ensure the scanner is receiving stable power and has a solid network connection.

1. Inspect the power and EtherNet/IP cables connected to the scanner for signs of damage, pinching, or abrasion.
2. Unscrew and re-seat the M12 connectors to ensure they are fully connected and secure.
3. If the fault persists and you are qualified to do so, use a multimeter to check for a stable 24VDC (+/- 10%) supply at the power connector pins.

Step 6: Review Scanner Configuration If no physical cause is found, the issue may be in the software configuration.

1. Connect to the scanner using a laptop with the NexBot Vision Configuration Software.
2. Go online with the scanner and use the monitoring tool to visualize the live scan data.
3. Verify that the defined protective and warning fields are appropriate for the application and do not overlap with any fixed objects in the cell.
4. Check the device's diagnostic buffer or error log for any other active faults.

Step 7: Reset and Verify Once the potential cause has been addressed, follow your system's standard procedure to reset the safety circuit and clear the fault from the robot controller. Observe the system to ensure the fault does not return.

Prevention

To prevent future occurrences of the F-107 fault:

• Incorporate regular cleaning of the scanner's optical window into your site's preventive maintenance schedule.
• Maintain good housekeeping within the robotic workcell to prevent debris from accumulating in safety zones.
• If the scanner is in a high-traffic area, consider installing a physical guard to protect it from impacts.
• Periodically audit the scanner's configuration to ensure the defined fields remain optimal for the application.

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