NXB-GEN-332-001 Scanner intermittently trips safety circuit on R-50 workcell

Description

We have a NexBot Robotics 332-001 Laser Safety Scanner installed on our R-50 welding cell. For the past week, the cell has been experiencing intermittent and unpredictable safety stops. The robot will stop mid-cycle, and the HMI reports a generic safety circuit fault. The scanner's status LED turns red, indicating a protective field intrusion, but we have visually confirmed multiple times that there is no personnel or equipment in the defined zone. We have cleaned the scanner's optical surface and checked the 24VDC power supply, which is stable. The EtherNet/IP connection also appears solid with no packet loss reported by the switch. The issue seems to happen more frequently in the afternoon. We recently installed some new stainless steel part fixtures in the cell, and we're wondering if reflections could be causing false trips. We need assistance diagnosing whether this is a configuration issue or a hardware malfunction.

Symptoms

• Robot cell enters a safety-stopped state without a visible obstruction.
• Scanner's OSSD (Output Signal Switching Device) outputs go low intermittently.
• Fault occurs randomly, sometimes hours apart.
• Scanner status indicator turns red during a fault event.

Resolution

The investigation determined the root cause was not a hardware fault but a combination of environmental factors and field configuration. The live scan data showed that specular reflections from a newly installed stainless steel fixture were intermittently being detected as an object within the protective field. Additionally, the default contamination monitoring settings were not sensitive enough for the ambient dust levels in the welding environment. The issue was resolved by precisely redrawing the protective field to exclude the reflective surface and by enabling a more aggressive dust filtering algorithm within the scanner's configuration software.

Resolution Steps

1. 1. Connected a laptop with NexBot Safety Configurator software to the same EtherNet/IP network as the scanner.
2. 2. Established a connection to the scanner and activated the live monitoring mode to visualize the scan data.
3. 3. Confirmed that intermittent, single-point detections were appearing at the edge of the protective field, corresponding to the location of the new steel fixture.
4. 4. Modified the active protective field by adjusting the polygon vertices to create a 75mm buffer around the reflective fixture.
5. 5. Navigated to the 'Filtering' tab in the device settings and changed the 'Contamination Function' from 'Standard' to 'High Dust Suppression'.
6. 6. Downloaded the new configuration to the NXB-GEN-332-001 scanner and performed a device restart.
7. 7. Tested the cell by placing certified test objects at various points to confirm correct detection and verified that the false trips no longer occurred during production runs.